Add description to file_store cargo metadata

Remove keyword from file_store cargo metadata
2023-03-20 12:45:33 -05:00 · 2023-03-20 12:37:22 -05:00
141 changed files with 11386 additions and 17967 deletions
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -1,8 +0,0 @@
-# Set update schedule for GitHub Actions
-version: 2
-updates:
-  - package-ecosystem: "github-actions"
-    directory: "/"
-    schedule:
-      # Check for updates to GitHub Actions every week
-      interval: "weekly"
--- a/.github/workflows/code_coverage.yml
+++ b/.github/workflows/code_coverage.yml
@@ -9,7 +9,7 @@ jobs:
    env:
      RUSTFLAGS: "-Cinstrument-coverage"
      RUSTDOCFLAGS: "-Cinstrument-coverage"
-      LLVM_PROFILE_FILE: "./target/coverage/%p-%m.profraw"
+      LLVM_PROFILE_FILE: "report-%p-%m.profraw"

    steps:
      - name: Checkout
@@ -19,7 +19,7 @@ jobs:
      - name: Install Rust toolchain
        uses: actions-rs/toolchain@v1
        with:
-            toolchain: stable
+            toolchain: "1.65.0"
            override: true
            profile: minimal
            components: llvm-tools-preview
@@ -27,7 +27,6 @@ jobs:
        uses: Swatinem/rust-cache@v2.2.1
      - name: Install grcov
        run: if [[ ! -e ~/.cargo/bin/grcov ]]; then cargo install grcov; fi
-        # TODO: re-enable the hwi tests
      - name: Build simulator image
        run: docker build -t hwi/ledger_emulator ./ci -f ci/Dockerfile.ledger
      - name: Run simulator image
@@ -40,16 +39,14 @@ jobs:
        run: pip install hwi==2.1.1 protobuf==3.20.1
      - name: Test
        run: cargo test --all-features
-      - name: Make coverage directory
-        run: mkdir coverage
      - name: Run grcov
-        run: grcov . --binary-path ./target/debug/ -s . -t lcov --branch --ignore-not-existing --keep-only '**/crates/**' --ignore '**/tests/**' --ignore '**/examples/**' -o ./coverage/lcov.info
+        run: mkdir coverage; grcov . --binary-path ./target/debug/ -s . -t lcov --branch --ignore-not-existing --ignore '/*' -o ./coverage/lcov.info
      - name: Generate HTML coverage report
-        run: genhtml -o coverage-report.html --ignore-errors source ./coverage/lcov.info
-      - name: Coveralls upload
-        uses: coverallsapp/github-action@master
-        with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
+        run: genhtml -o coverage-report.html ./coverage/lcov.info
+          #      - name: Coveralls upload
+          #        uses: coverallsapp/github-action@master
+          #        with:
+          #          github-token: ${{ secrets.GITHUB_TOKEN }}
      - name: Upload artifact
        uses: actions/upload-artifact@v2
        with:
--- a/.github/workflows/cont_integration.yml
+++ b/.github/workflows/cont_integration.yml
@@ -12,7 +12,7 @@ jobs:
        rust:
          - version: stable
            clippy: true
-          - version: 1.63.0 # MSRV
+          - version: 1.57.0 # MSRV
        features:
          - --no-default-features
          - --all-features
@@ -27,46 +27,11 @@ jobs:
            profile: minimal
      - name: Rust Cache
        uses: Swatinem/rust-cache@v2.2.1
-      - name: Pin dependencies for MSRV
-        if: matrix.rust.version == '1.63.0'
-        run: |
-          cargo update -p zstd-sys --precise "2.0.8+zstd.1.5.5"
-          cargo update -p time --precise "0.3.20"
-          cargo update -p home --precise "0.5.5"
-          cargo update -p proptest --precise "1.2.0"
      - name: Build
        run: cargo build ${{ matrix.features }}
      - name: Test
        run: cargo test ${{ matrix.features }}

-  check-no-std:
-    name: Check no_std
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v2
-      - name: Install Rust toolchain
-        uses: actions-rs/toolchain@v1
-        with:
-          toolchain: stable
-          override: true
-          profile: minimal
-          # target: "thumbv6m-none-eabi"
-      - name: Rust Cache
-        uses: Swatinem/rust-cache@v2.2.1
-      - name: Check bdk_chain
-        working-directory: ./crates/chain
-        # TODO "--target thumbv6m-none-eabi" should work but currently does not
-        run: cargo check --no-default-features --features bitcoin/no-std,miniscript/no-std,hashbrown
-      - name: Check bdk
-        working-directory: ./crates/bdk
-        # TODO "--target thumbv6m-none-eabi" should work but currently does not
-        run: cargo check --no-default-features --features bitcoin/no-std,miniscript/no-std,bdk_chain/hashbrown
-      - name: Check esplora
-        working-directory: ./crates/esplora
-        # TODO "--target thumbv6m-none-eabi" should work but currently does not
-        run: cargo check --no-default-features --features bitcoin/no-std,miniscript/no-std,bdk_chain/hashbrown
-
  check-wasm:
    name: Check WASM
    runs-on: ubuntu-20.04
@@ -78,6 +43,7 @@ jobs:
        uses: actions/checkout@v2
        # Install a recent version of clang that supports wasm32
      - run: wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add - || exit 1
+      - run: sudo apt-add-repository "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-10 main" || exit 1
      - run: sudo apt-get update || exit 1
      - run: sudo apt-get install -y libclang-common-10-dev clang-10 libc6-dev-i386 || exit 1
      - name: Install Rust toolchain
@@ -91,10 +57,10 @@ jobs:
        uses: Swatinem/rust-cache@v2.2.1
      - name: Check bdk
        working-directory: ./crates/bdk
-        run: cargo check --target wasm32-unknown-unknown --no-default-features --features bitcoin/no-std,miniscript/no-std,bdk_chain/hashbrown,dev-getrandom-wasm
+        run: cargo check --target wasm32-unknown-unknown --features dev-getrandom-wasm
      - name: Check esplora
        working-directory: ./crates/esplora
-        run: cargo check --target wasm32-unknown-unknown --no-default-features --features bitcoin/no-std,miniscript/no-std,bdk_chain/hashbrown,async
+        run: cargo check --target wasm32-unknown-unknown --features async --no-default-features

  fmt:
    name: Rust fmt
@@ -118,7 +84,9 @@ jobs:
      - uses: actions/checkout@v1
      - uses: actions-rs/toolchain@v1
        with:
-            toolchain: stable
+            # we pin clippy instead of using "stable" so that our CI doesn't break
+            # at each new cargo release
+            toolchain: "1.67.0"
            components: clippy
            override: true
      - name: Rust Cache
--- a/.github/workflows/nightly_docs.yml
+++ b/.github/workflows/nightly_docs.yml
@@ -17,8 +17,6 @@ jobs:
        run: rustup update
      - name: Rust Cache
        uses: Swatinem/rust-cache@v2.2.1
-      - name: Pin dependencies for MSRV
-        run: cargo update -p home --precise "0.5.5"
      - name: Build docs
        run: cargo doc --no-deps
        env:
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,3 @@ Cargo.lock

 *.swp
 .idea
-
-# Example persisted files.
-*.db
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -158,7 +158,7 @@ BDK and LDK together.
 - Add the ability to specify which leaves to sign in a taproot transaction through `TapLeavesOptions` in `SignOptions`
 - Add the ability to specify whether a taproot transaction should be signed using the internal key or not, using `sign_with_tap_internal_key` in `SignOptions`
 - Consolidate params `fee_amount` and `amount_needed` in `target_amount` in `CoinSelectionAlgorithm::coin_select` signature.
- Change the meaning of the `fee_amount` field inside `CoinSelectionResult`: from now on the `fee_amount` will represent only the fees associated with the utxos in the `selected` field of `CoinSelectionResult`.
+- Change the meaning of the `fee_amount` field inside `CoinSelectionResult`: from now on the `fee_amount` will represent only the fees asociated with the utxos in the `selected` field of `CoinSelectionResult`.
 - New `RpcBlockchain` implementation with various fixes.
 - Return balance in separate categories, namely `confirmed`, `trusted_pending`, `untrusted_pending` & `immature`.

@@ -449,7 +449,7 @@ final transaction is created by calling `finish` on the builder.
 #### Changed
 - Simplify the architecture of blockchain traits
 - Improve sync
- Remove unused variant `HeaderParseFail`
+- Remove unused varaint HeaderParseFail

 ### CLI
 #### Added
@@ -517,7 +517,7 @@ final transaction is created by calling `finish` on the builder.
 - Default to SIGHASH_ALL if not specified
 - Replace ChangeSpendPolicy::filter_utxos with a predicate
 - Make 'unspendable' into a HashSet
- Stop implicitly enforcing manual selection by .add_utxo
+- Stop implicitly enforcing manaul selection by .add_utxo
 - Rename DumbCS to LargestFirstCoinSelection
 - Rename must_use_utxos to required_utxos
 - Rename may_use_utxos to optional_uxtos
@@ -529,7 +529,7 @@ final transaction is created by calling `finish` on the builder.
 - Use TXIN_DEFAULT_WEIGHT constant in coin selection
 - Replace `must_use` with `required` in coin selection
 - Take both spending policies into account in create_tx
- Check last derivation in cache to avoid recomputing
+- Check last derivation in cache to avoid recomputation
 - Use the branch-and-bound cs by default
 - Make coin_select return UTXOs instead of TxIns
 - Build output lookup inside complete transaction
@@ -550,7 +550,7 @@ final transaction is created by calling `finish` on the builder.
 - Require esplora feature for repl example

 #### Security
- Use dirs-next instead of dirs since the latter is unmaintained
+- Use dirs-next instead of dirs since the latter is unmantained

 ## [0.1.0-beta.1] - 2020-09-08

--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -28,7 +28,7 @@ The codebase is maintained using the "contributor workflow" where everyone
 without exception contributes patch proposals using "pull requests". This
 facilitates social contribution, easy testing and peer review.

-To contribute a patch, the workflow is as follows:
+To contribute a patch, the worflow is a as follows:

  1. Fork Repository
  2. Create topic branch
@@ -46,15 +46,15 @@ Every new feature should be covered by functional tests where possible.
 When refactoring, structure your PR to make it easy to review and don't
 hesitate to split it into multiple small, focused PRs.

-The Minimal Supported Rust Version is **1.57.0** (enforced by our CI).
+The Minimal Supported Rust Version is 1.46 (enforced by our CI).

 Commits should cover both the issue fixed and the solution's rationale.
-These [guidelines](https://chris.beams.io/posts/git-commit/) should be kept in mind. Commit messages should follow the ["Conventional Commits 1.0.0"](https://www.conventionalcommits.org/en/v1.0.0/) to make commit histories easier to read by humans and automated tools. 
+These [guidelines](https://chris.beams.io/posts/git-commit/) should be kept in mind.

 To facilitate communication with other contributors, the project is making use
 of GitHub's "assignee" field. First check that no one is assigned and then
 comment suggesting that you're working on it. If someone is already assigned,
-don't hesitate to ask if the assigned party or previous commenter are still
+don't hesitate to ask if the assigned party or previous commenters are still
 working on it if it has been awhile.

 Deprecation policy
@@ -91,7 +91,7 @@ This is also enforced by the CI.
 Security
 --------

-Security is a high priority of BDK; disclosure of security vulnerabilities helps
+Security is a high priority of BDK; disclosure of security vulnerabilites helps
 prevent user loss of funds.

 Note that BDK is currently considered "pre-production" during this time, there
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,22 +1,15 @@
 [workspace]
-resolver = "2"
 members = [
    "crates/bdk",
    "crates/chain",
    "crates/file_store",
    "crates/electrum",
-    "crates/esplora",
-    "crates/bitcoind_rpc",
-    "crates/hwi",
-    "crates/testenv",
-    "example-crates/example_cli",
-    "example-crates/example_electrum",
-    "example-crates/example_esplora",
-    "example-crates/example_bitcoind_rpc_polling",
+    "example-crates/keychain_tracker_electrum",
+    "example-crates/keychain_tracker_esplora",
+    "example-crates/keychain_tracker_example_cli",
    "example-crates/wallet_electrum",
-    "example-crates/wallet_esplora_blocking",
+    "example-crates/wallet_esplora",
    "example-crates/wallet_esplora_async",
-    "example-crates/wallet_rpc",
    "nursery/tmp_plan",
    "nursery/coin_select"
 ]
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@
    <a href="https://github.com/bitcoindevkit/bdk/actions?query=workflow%3ACI"><img alt="CI Status" src="https://github.com/bitcoindevkit/bdk/workflows/CI/badge.svg"></a>
    <a href="https://coveralls.io/github/bitcoindevkit/bdk?branch=master"><img src="https://coveralls.io/repos/github/bitcoindevkit/bdk/badge.svg?branch=master"/></a>
    <a href="https://docs.rs/bdk"><img alt="API Docs" src="https://img.shields.io/badge/docs.rs-bdk-green"/></a>
-    <a href="https://blog.rust-lang.org/2022/08/11/Rust-1.63.0.html"><img alt="Rustc Version 1.63.0+" src="https://img.shields.io/badge/rustc-1.63.0%2B-lightgrey.svg"/></a>
+    <a href="https://blog.rust-lang.org/2021/12/02/Rust-1.57.0.html"><img alt="Rustc Version 1.57.0+" src="https://img.shields.io/badge/rustc-1.57.0%2B-lightgrey.svg"/></a>
    <a href="https://discord.gg/d7NkDKm"><img alt="Chat on Discord" src="https://img.shields.io/discord/753336465005608961?logo=discord"></a>
  </p>

@@ -33,7 +33,7 @@ It is built upon the excellent [`rust-bitcoin`] and [`rust-miniscript`] crates.

 > ⚠ The Bitcoin Dev Kit developers are in the process of releasing a `v1.0` which is a fundamental re-write of how the library works.
 > See for some background on this project: https://bitcoindevkit.org/blog/road-to-bdk-1/ (ignore the timeline 😁)
-> For a release timeline see the [`BDK 1.0 project page`].
+> For a release timeline see the [`bdk_core_staging`] repo where a lot of the component work is being done. The plan is that everything in the `bdk_core_staging` repo will be moved into the `crates` directory here.

 ## Architecture

@@ -45,52 +45,10 @@ The project is split up into several crates in the `/crates` directory:
 - [`esplora`](./crates/esplora): Extends the [`esplora-client`] crate with methods to fetch chain data from an esplora HTTP server in the form that [`bdk_chain`] and `Wallet` can consume.
 - [`electrum`](./crates/electrum): Extends the [`electrum-client`] crate with methods to fetch chain data from an electrum server in the form that [`bdk_chain`] and `Wallet` can consume.

-Fully working examples of how to use these components are in `/example-crates`:
- [`example_cli`](./example-crates/example_cli): Library used by the `example_*` crates. Provides utilities for syncing, showing the balance, generating addresses and creating transactions without using the bdk `Wallet`.
- [`example_electrum`](./example-crates/example_electrum): A command line Bitcoin wallet application built on top of `example_cli` and the `electrum` crate. It shows the power of the bdk tools (`chain` + `file_store` + `electrum`), without depending on the main `bdk` library.
- [`example_esplora`](./example-crates/example_esplora): A command line Bitcoin wallet application built on top of `example_cli` and the `esplora` crate. It shows the power of the bdk tools (`chain` + `file_store` + `esplora`), without depending on the main `bdk` library.
- [`example_bitcoind_rpc_polling`](./example-crates/example_bitcoind_rpc_polling): A command line Bitcoin wallet application built on top of `example_cli` and the `bitcoind_rpc` crate. It shows the power of the bdk tools (`chain` + `file_store` + `bitcoind_rpc`), without depending on the main `bdk` library.
- [`wallet_esplora_blocking`](./example-crates/wallet_esplora_blocking): Uses the `Wallet` to sync and spend using the Esplora blocking interface.
- [`wallet_esplora_async`](./example-crates/wallet_esplora_async): Uses the `Wallet` to sync and spend using the Esplora asynchronous interface.
- [`wallet_electrum`](./example-crates/wallet_electrum): Uses the `Wallet` to sync and spend using Electrum.
+Fully working examples of how to use these components are in `/example-crates`

-[`BDK 1.0 project page`]: https://github.com/orgs/bitcoindevkit/projects/14
+[`bdk_core_staging`]: https://github.com/LLFourn/bdk_core_staging
 [`rust-miniscript`]: https://github.com/rust-bitcoin/rust-miniscript
 [`rust-bitcoin`]: https://github.com/rust-bitcoin/rust-bitcoin
-[`esplora-client`]: https://docs.rs/esplora-client/
-[`electrum-client`]: https://docs.rs/electrum-client/
-[`bdk_chain`]: https://docs.rs/bdk-chain/
-
-## Minimum Supported Rust Version (MSRV)
-This library should compile with any combination of features with Rust 1.63.0.
-
-To build with the MSRV you will need to pin dependencies as follows:
-
-```shell
-# zip 0.6.3 has MSRV 1.64.0
-cargo update -p zip --precise "0.6.2"
-# time 0.3.21 has MSRV 1.65.0
-cargo update -p time --precise "0.3.20"
-# jobserver 0.1.27 has MSRV 1.66.0
-cargo update -p jobserver --precise "0.1.26"
-# home 0.5.9 has MSRV 1.70.0
-cargo update -p home --precise "0.5.5"
-# proptest 1.4.0 has MSRV 1.65.0
-cargo update -p proptest --precise "1.2.0"
-```
-
-## License
-
-Licensed under either of
-
-* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or <https://www.apache.org/licenses/LICENSE-2.0>)
-* MIT license ([LICENSE-MIT](LICENSE-MIT) or <https://opensource.org/licenses/MIT>)
-
-at your option.
-
-### Contribution
-
-Unless you explicitly state otherwise, any contribution intentionally
-submitted for inclusion in the work by you, as defined in the Apache-2.0
-license, shall be dual licensed as above, without any additional terms or
-conditions.
+[`esplora-client`]: https://docs.rs/esplora-client/0.3.0/esplora_client/
+[`electrum-client`]: https://docs.rs/electrum-client/0.13.0/electrum_client/
--- a/clippy.toml
+++ b/clippy.toml
@@ -1 +1 @@
-msrv="1.63.0"
+msrv="1.57.0"
--- a/crates/bdk/Cargo.toml
+++ b/crates/bdk/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "bdk"
 homepage = "https://bitcoindevkit.org"
-version = "1.0.0-alpha.9"
+version = "1.0.0-alpha.0"
 repository = "https://github.com/bitcoindevkit/bdk"
 documentation = "https://docs.rs/bdk"
 description = "A modern, lightweight, descriptor-based wallet library"
@@ -10,29 +10,35 @@ readme = "README.md"
 license = "MIT OR Apache-2.0"
 authors = ["Bitcoin Dev Kit Developers"]
 edition = "2021"
-rust-version = "1.63"
+rust-version = "1.57"

 [dependencies]
+log = "^0.4"
 rand = "^0.8"
-miniscript = { version = "11.0.0", features = ["serde"], default-features = false }
-bitcoin = { version = "0.31.0", features = ["serde", "base64", "rand-std"], default-features = false }
+miniscript = { version = "9", features = ["serde"] }
+bitcoin = { version = "0.29", features = ["serde", "base64", "rand"] }
 serde = { version = "^1.0", features = ["derive"] }
 serde_json = { version = "^1.0" }
-bdk_chain = { path = "../chain", version = "0.12.0", features = ["miniscript", "serde"], default-features = false }
+bdk_chain = { path = "../chain", version = "0.4.0", features = ["miniscript", "serde"] }

 # Optional dependencies
-bip39 = { version = "2.0", optional = true }
+hwi = { version = "0.5", optional = true, features = [ "use-miniscript"] }
+bip39 = { version = "1.0.1", optional = true }

 [target.'cfg(target_arch = "wasm32")'.dependencies]
 getrandom = "0.2"
 js-sys = "0.3"

+
 [features]
 default = ["std"]
-std = ["bitcoin/std", "miniscript/std", "bdk_chain/std"]
+std = []
 compiler = ["miniscript/compiler"]
 all-keys = ["keys-bip39"]
 keys-bip39 = ["bip39"]
+hardware-signer = ["hwi"]
+test-hardware-signer = ["hardware-signer"]
+

 # This feature is used to run `cargo check` in our CI targeting wasm. It's not recommended
 # for libraries to explicitly include the "getrandom/js" feature, so we only do it when
@@ -41,15 +47,17 @@ dev-getrandom-wasm = ["getrandom/js"]

 [dev-dependencies]
 lazy_static = "1.4"
+env_logger = "0.7"
+# Move back to importing from rust-bitcoin once https://github.com/rust-bitcoin/rust-bitcoin/pull/1342 is released
+base64 = "^0.13"
 assert_matches = "1.5.0"
-tempfile = "3"
-bdk_file_store = { path = "../file_store" }
-anyhow = "1"
+

 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]

+
 [[example]]
 name = "mnemonic_to_descriptors"
 path = "examples/mnemonic_to_descriptors.rs"
--- a/crates/bdk/LICENSE
+++ b/crates/bdk/LICENSE
--- a/crates/bdk/LICENSE-APACHE
+++ b/crates/bdk/LICENSE-APACHE
--- a/crates/bdk/LICENSE-MIT
+++ b/crates/bdk/LICENSE-MIT
--- a/crates/bdk/README.md
+++ b/crates/bdk/README.md
@@ -13,7 +13,7 @@
    <a href="https://github.com/bitcoindevkit/bdk/actions?query=workflow%3ACI"><img alt="CI Status" src="https://github.com/bitcoindevkit/bdk/workflows/CI/badge.svg"></a>
    <a href="https://coveralls.io/github/bitcoindevkit/bdk?branch=master"><img src="https://coveralls.io/repos/github/bitcoindevkit/bdk/badge.svg?branch=master"/></a>
    <a href="https://docs.rs/bdk"><img alt="API Docs" src="https://img.shields.io/badge/docs.rs-bdk-green"/></a>
-    <a href="https://blog.rust-lang.org/2022/08/11/Rust-1.63.0.html"><img alt="Rustc Version 1.63.0+" src="https://img.shields.io/badge/rustc-1.63.0%2B-lightgrey.svg"/></a>
+    <a href="https://blog.rust-lang.org/2021/12/02/Rust-1.57.0.html"><img alt="Rustc Version 1.57.0+" src="https://img.shields.io/badge/rustc-1.57.0%2B-lightgrey.svg"/></a>
    <a href="https://discord.gg/d7NkDKm"><img alt="Chat on Discord" src="https://img.shields.io/discord/753336465005608961?logo=discord"></a>
  </p>

@@ -26,7 +26,7 @@

 ## `bdk`

-The `bdk` crate provides the [`Wallet`] type which is a simple, high-level
+The `bdk` crate provides the [`Wallet`](`crate::Wallet`) type which is a simple, high-level
 interface built from the low-level components of [`bdk_chain`]. `Wallet` is a good starting point
 for many simple applications as well as a good demonstration of how to use the other mechanisms to
 construct a wallet. It has two keychains (external and internal) which are defined by
@@ -34,51 +34,51 @@ construct a wallet. It has two keychains (external and internal) which are defin
 chain data it also uses the descriptors to find transaction outputs owned by them. From there, you
 can create and sign transactions.

-For details about the API of `Wallet` see the [module-level documentation][`Wallet`].
+For more information, see the [`Wallet`'s documentation](https://docs.rs/bdk/latest/bdk/wallet/struct.Wallet.html).

 ### Blockchain data

-In order to get blockchain data for `Wallet` to consume, you should configure a client from
-an available chain source. Typically you make a request to the chain source and get a response
-that the `Wallet` can use to update its view of the chain.
+In order to get blockchain data for `Wallet` to consume, you have to put it into particular form.
+Right now this is [`KeychainScan`] which is defined in [`bdk_chain`].
+
+This can be created manually or from blockchain-scanning crates.

 **Blockchain Data Sources**

 * [`bdk_esplora`]: Grabs blockchain data from Esplora for updating BDK structures.
 * [`bdk_electrum`]: Grabs blockchain data from Electrum for updating BDK structures.
-* [`bdk_bitcoind_rpc`]: Grabs blockchain data from Bitcoin Core for updating BDK structures.

 **Examples**

-* [`example-crates/wallet_esplora_async`](https://github.com/bitcoindevkit/bdk/tree/master/example-crates/wallet_esplora_async)
-* [`example-crates/wallet_esplora_blocking`](https://github.com/bitcoindevkit/bdk/tree/master/example-crates/wallet_esplora_blocking)
+* [`example-crates/wallet_esplora`](https://github.com/bitcoindevkit/bdk/tree/master/example-crates/wallet_esplora)
 * [`example-crates/wallet_electrum`](https://github.com/bitcoindevkit/bdk/tree/master/example-crates/wallet_electrum)
-* [`example-crates/wallet_rpc`](https://github.com/bitcoindevkit/bdk/tree/master/example-crates/wallet_rpc)

 ### Persistence

-To persist the `Wallet` on disk, it must be constructed with a [`PersistBackend`] implementation.
+To persist the `Wallet` on disk, `Wallet` needs to be constructed with a
+[`Persist`](https://docs.rs/bdk_chain/latest/bdk_chain/keychain/struct.KeychainPersist.html) implementation.

 **Implementations**

-* [`bdk_file_store`]: A simple flat-file implementation of [`PersistBackend`].
+* [`bdk_file_store`]: a simple flat-file implementation of `Persist`.

 **Example**

-<!-- compile_fail because outpoint and txout are fake variables -->
-```rust,compile_fail
-use bdk::{bitcoin::Network, wallet::{ChangeSet, Wallet}};
+```rust
+use bdk::{bitcoin::Network, wallet::{AddressIndex, Wallet}};

 fn main() {
-    // Create a new file `Store`.
-    let db = bdk_file_store::Store::<ChangeSet>::open_or_create_new(b"magic_bytes", "path/to/my_wallet.db").expect("create store");
+    // a type that implements `Persist`
+    let db = ();

-    let descriptor = "wpkh(tprv8ZgxMBicQKsPdcAqYBpzAFwU5yxBUo88ggoBqu1qPcHUfSbKK1sKMLmC7EAk438btHQrSdu3jGGQa6PA71nvH5nkDexhLteJqkM4dQmWF9g/84'/1'/0'/0/*)";
-    let mut wallet = Wallet::new_or_load(descriptor, None, db, Network::Testnet).expect("create or load wallet");
+    let descriptor = "wpkh(tprv8ZgxMBicQKsPdy6LMhUtFHAgpocR8GC6QmwMSFpZs7h6Eziw3SpThFfczTDh5rW2krkqffa11UpX3XkeTTB2FvzZKWXqPY54Y6Rq4AQ5R8L/84'/0'/0'/0/*)";
+    let mut wallet = Wallet::new(descriptor, None, db, Network::Testnet).expect("should create");

-    // Insert a single `TxOut` at `OutPoint` into the wallet.
-    let _ = wallet.insert_txout(outpoint, txout);
-    wallet.commit().expect("must write to database");
+    // get a new address (this increments revealed derivation index)
+    println!("revealed address: {}", wallet.get_address(AddressIndex::New));
+    println!("staged changes: {:?}", wallet.staged());
+    // persist changes
+    wallet.commit().expect("must save");
 }
 ```

@@ -137,7 +137,7 @@ fn main() {
 <!-- use bdk::electrum_client::Client; -->
 <!-- use bdk::wallet::AddressIndex::New; -->

-<!-- use bitcoin::base64; -->
+<!-- use base64; -->
 <!-- use bdk::bitcoin::consensus::serialize; -->
 <!-- use bdk::bitcoin::Network; -->

@@ -174,7 +174,7 @@ fn main() {
 <!-- ```rust,no_run -->
 <!-- use bdk::{Wallet, SignOptions}; -->

-<!-- use bitcoin::base64; -->
+<!-- use base64; -->
 <!-- use bdk::bitcoin::consensus::deserialize; -->
 <!-- use bdk::bitcoin::Network; -->

@@ -206,23 +206,22 @@ cargo test

 Licensed under either of

-* Apache License, Version 2.0, ([LICENSE-APACHE](../../LICENSE-APACHE) or <https://www.apache.org/licenses/LICENSE-2.0>)
-* MIT license ([LICENSE-MIT](../../LICENSE-MIT) or <https://opensource.org/licenses/MIT>)
+ * Apache License, Version 2.0
+   ([LICENSE-APACHE](LICENSE-APACHE) or <https://www.apache.org/licenses/LICENSE-2.0>)
+ * MIT license
+   ([LICENSE-MIT](LICENSE-MIT) or <https://opensource.org/licenses/MIT>)

 at your option.

-### Contribution
+## Contribution

-Unless you explicitly state otherwise, any contribution intentionally
-submitted for inclusion in the work by you, as defined in the Apache-2.0
-license, shall be dual licensed as above, without any additional terms or
-conditions.
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
+dual licensed as above, without any additional terms or conditions.

-[`Wallet`]: https://docs.rs/bdk/1.0.0-alpha.7/bdk/wallet/struct.Wallet.html
-[`PersistBackend`]: https://docs.rs/bdk_chain/latest/bdk_chain/trait.PersistBackend.html
 [`bdk_chain`]: https://docs.rs/bdk_chain/latest
 [`bdk_file_store`]: https://docs.rs/bdk_file_store/latest
 [`bdk_electrum`]: https://docs.rs/bdk_electrum/latest
 [`bdk_esplora`]: https://docs.rs/bdk_esplora/latest
-[`bdk_bitcoind_rpc`]: https://docs.rs/bdk_bitcoind_rpc/latest
+[`KeychainScan`]: https://docs.rs/bdk_chain/latest/bdk_chain/keychain/struct.KeychainScan.html
 [`rust-miniscript`]: https://docs.rs/miniscript/latest/miniscript/index.html
--- a/crates/bdk/examples/compiler.rs
+++ b/crates/bdk/examples/compiler.rs
@@ -11,12 +11,15 @@

 extern crate bdk;
 extern crate bitcoin;
+extern crate log;
 extern crate miniscript;
 extern crate serde_json;

 use std::error::Error;
 use std::str::FromStr;

+use log::info;
+
 use bitcoin::Network;
 use miniscript::policy::Concrete;
 use miniscript::Descriptor;
@@ -33,9 +36,13 @@ use bdk::{KeychainKind, Wallet};
 /// This example demonstrates the interaction between a bdk wallet and miniscript policy.

 fn main() -> Result<(), Box<dyn Error>> {
+    env_logger::init_from_env(
+        env_logger::Env::default().filter_or(env_logger::DEFAULT_FILTER_ENV, "info"),
+    );
+
    // We start with a generic miniscript policy string
    let policy_str = "or(10@thresh(4,pk(029ffbe722b147f3035c87cb1c60b9a5947dd49c774cc31e94773478711a929ac0),pk(025f05815e3a1a8a83bfbb03ce016c9a2ee31066b98f567f6227df1d76ec4bd143),pk(025625f41e4a065efc06d5019cbbd56fe8c07595af1231e7cbc03fafb87ebb71ec),pk(02a27c8b850a00f67da3499b60562673dcf5fdfb82b7e17652a7ac54416812aefd),pk(03e618ec5f384d6e19ca9ebdb8e2119e5bef978285076828ce054e55c4daf473e2)),1@and(older(4209713),thresh(2,pk(03deae92101c790b12653231439f27b8897264125ecb2f46f48278603102573165),pk(033841045a531e1adf9910a6ec279589a90b3b8a904ee64ffd692bd08a8996c1aa),pk(02aebf2d10b040eb936a6f02f44ee82f8b34f5c1ccb20ff3949c2b28206b7c1068))))";
-    println!("Compiling policy: \n{}", policy_str);
+    info!("Compiling policy: \n{}", policy_str);

    // Parse the string as a [`Concrete`] type miniscript policy.
    let policy = Concrete::<String>::from_str(policy_str)?;
@@ -44,12 +51,12 @@ fn main() -> Result<(), Box<dyn Error>> {
    // `policy.compile()` returns the resulting miniscript from the policy.
    let descriptor = Descriptor::new_wsh(policy.compile()?)?;

-    println!("Compiled into following Descriptor: \n{}", descriptor);
+    info!("Compiled into following Descriptor: \n{}", descriptor);

    // Create a new wallet from this descriptor
    let mut wallet = Wallet::new_no_persist(&format!("{}", descriptor), None, Network::Regtest)?;

-    println!(
+    info!(
        "First derived address from the descriptor: \n{}",
        wallet.get_address(New)
    );
@@ -57,7 +64,7 @@ fn main() -> Result<(), Box<dyn Error>> {
    // BDK also has it's own `Policy` structure to represent the spending condition in a more
    // human readable json format.
    let spending_policy = wallet.policies(KeychainKind::External)?;
-    println!(
+    info!(
        "The BDK spending policy: \n{}",
        serde_json::to_string_pretty(&spending_policy)?
    );
--- a/crates/bdk/examples/mnemonic_to_descriptors.rs
+++ b/crates/bdk/examples/mnemonic_to_descriptors.rs
@@ -6,20 +6,21 @@
 // You may not use this file except in accordance with one or both of these
 // licenses.

-use anyhow::anyhow;
-use bdk::bitcoin::bip32::DerivationPath;
 use bdk::bitcoin::secp256k1::Secp256k1;
+use bdk::bitcoin::util::bip32::DerivationPath;
 use bdk::bitcoin::Network;
 use bdk::descriptor;
 use bdk::descriptor::IntoWalletDescriptor;
 use bdk::keys::bip39::{Language, Mnemonic, WordCount};
 use bdk::keys::{GeneratableKey, GeneratedKey};
 use bdk::miniscript::Tap;
+use bdk::Error as BDK_Error;
+use std::error::Error;
 use std::str::FromStr;

 /// This example demonstrates how to generate a mnemonic phrase
 /// using BDK and use that to generate a descriptor string.
-fn main() -> Result<(), anyhow::Error> {
+fn main() -> Result<(), Box<dyn Error>> {
    let secp = Secp256k1::new();

    // In this example we are generating a 12 words mnemonic phrase
@@ -27,14 +28,14 @@ fn main() -> Result<(), anyhow::Error> {
    // using their respective `WordCount` variant.
    let mnemonic: GeneratedKey<_, Tap> =
        Mnemonic::generate((WordCount::Words12, Language::English))
-            .map_err(|_| anyhow!("Mnemonic generation error"))?;
+            .map_err(|_| BDK_Error::Generic("Mnemonic generation error".to_string()))?;

    println!("Mnemonic phrase: {}", *mnemonic);
    let mnemonic_with_passphrase = (mnemonic, None);

    // define external and internal derivation key path
-    let external_path = DerivationPath::from_str("m/86h/1h/0h/0").unwrap();
-    let internal_path = DerivationPath::from_str("m/86h/1h/0h/1").unwrap();
+    let external_path = DerivationPath::from_str("m/86h/0h/0h/0").unwrap();
+    let internal_path = DerivationPath::from_str("m/86h/0h/0h/1").unwrap();

    // generate external and internal descriptor from mnemonic
    let (external_descriptor, ext_keymap) =
--- a/crates/bdk/examples/policy.rs
+++ b/crates/bdk/examples/policy.rs
@@ -10,6 +10,8 @@
 // licenses.

 extern crate bdk;
+extern crate env_logger;
+extern crate log;
 use std::error::Error;

 use bdk::bitcoin::Network;
@@ -27,6 +29,10 @@ use bdk::wallet::signer::SignersContainer;
 /// one of the Extend Private key.

 fn main() -> Result<(), Box<dyn Error>> {
+    env_logger::init_from_env(
+        env_logger::Env::default().filter_or(env_logger::DEFAULT_FILTER_ENV, "info"),
+    );
+
    let secp = bitcoin::secp256k1::Secp256k1::new();

    // The descriptor used in the example
@@ -42,7 +48,7 @@ fn main() -> Result<(), Box<dyn Error>> {
    // But they can be used as independent tools also.
    let (wallet_desc, keymap) = desc.into_wallet_descriptor(&secp, Network::Testnet)?;

-    println!("Example Descriptor for policy analysis : {}", wallet_desc);
+    log::info!("Example Descriptor for policy analysis : {}", wallet_desc);

    // Create the signer with the keymap and descriptor.
    let signers_container = SignersContainer::build(keymap, &wallet_desc, &secp);
@@ -54,7 +60,7 @@ fn main() -> Result<(), Box<dyn Error>> {
        .extract_policy(&signers_container, BuildSatisfaction::None, &secp)?
        .expect("We expect a policy");

-    println!("Derived Policy for the descriptor {:#?}", policy);
+    log::info!("Derived Policy for the descriptor {:#?}", policy);

    Ok(())
 }
--- a/crates/bdk/src/descriptor/checksum.rs
+++ b/crates/bdk/src/descriptor/checksum.rs
@@ -42,16 +42,22 @@ fn poly_mod(mut c: u64, val: u64) -> u64 {
    c
 }

-/// Compute the checksum bytes of a descriptor, excludes any existing checksum in the descriptor string from the calculation
-pub fn calc_checksum_bytes(mut desc: &str) -> Result<[u8; 8], DescriptorError> {
+/// Computes the checksum bytes of a descriptor.
+/// `exclude_hash = true` ignores all data after the first '#' (inclusive).
+pub(crate) fn calc_checksum_bytes_internal(
+    mut desc: &str,
+    exclude_hash: bool,
+) -> Result<[u8; 8], DescriptorError> {
    let mut c = 1;
    let mut cls = 0;
    let mut clscount = 0;

    let mut original_checksum = None;
-    if let Some(split) = desc.split_once('#') {
-        desc = split.0;
-        original_checksum = Some(split.1);
+    if exclude_hash {
+        if let Some(split) = desc.split_once('#') {
+            desc = split.0;
+            original_checksum = Some(split.1);
+        }
    }

    for ch in desc.as_bytes() {
@@ -89,10 +95,39 @@ pub fn calc_checksum_bytes(mut desc: &str) -> Result<[u8; 8], DescriptorError> {
    Ok(checksum)
 }

+/// Compute the checksum bytes of a descriptor, excludes any existing checksum in the descriptor string from the calculation
+pub fn calc_checksum_bytes(desc: &str) -> Result<[u8; 8], DescriptorError> {
+    calc_checksum_bytes_internal(desc, true)
+}
+
 /// Compute the checksum of a descriptor, excludes any existing checksum in the descriptor string from the calculation
 pub fn calc_checksum(desc: &str) -> Result<String, DescriptorError> {
    // unsafe is okay here as the checksum only uses bytes in `CHECKSUM_CHARSET`
-    calc_checksum_bytes(desc).map(|b| unsafe { String::from_utf8_unchecked(b.to_vec()) })
+    calc_checksum_bytes_internal(desc, true)
+        .map(|b| unsafe { String::from_utf8_unchecked(b.to_vec()) })
+}
+
+// TODO in release 0.25.0, remove get_checksum_bytes and get_checksum
+// TODO in release 0.25.0, consolidate calc_checksum_bytes_internal into calc_checksum_bytes
+
+/// Compute the checksum bytes of a descriptor
+#[deprecated(
+    since = "0.24.0",
+    note = "Use new `calc_checksum_bytes` function which excludes any existing checksum in the descriptor string before calculating the checksum hash bytes. See https://github.com/bitcoindevkit/bdk/pull/765."
+)]
+pub fn get_checksum_bytes(desc: &str) -> Result<[u8; 8], DescriptorError> {
+    calc_checksum_bytes_internal(desc, false)
+}
+
+/// Compute the checksum of a descriptor
+#[deprecated(
+    since = "0.24.0",
+    note = "Use new `calc_checksum` function which excludes any existing checksum in the descriptor string before calculating the checksum hash. See https://github.com/bitcoindevkit/bdk/pull/765."
+)]
+pub fn get_checksum(desc: &str) -> Result<String, DescriptorError> {
+    // unsafe is okay here as the checksum only uses bytes in `CHECKSUM_CHARSET`
+    calc_checksum_bytes_internal(desc, false)
+        .map(|b| unsafe { String::from_utf8_unchecked(b.to_vec()) })
 }

 #[cfg(test)]
--- a/crates/bdk/src/descriptor/dsl.rs
+++ b/crates/bdk/src/descriptor/dsl.rs
@@ -274,13 +274,14 @@ macro_rules! impl_sortedmulti {
 #[macro_export]
 macro_rules! parse_tap_tree {
    ( @merge $tree_a:expr, $tree_b:expr) => {{
+        use $crate::alloc::sync::Arc;
        use $crate::miniscript::descriptor::TapTree;

        $tree_a
            .and_then(|tree_a| Ok((tree_a, $tree_b?)))
            .and_then(|((a_tree, mut a_keymap, a_networks), (b_tree, b_keymap, b_networks))| {
                a_keymap.extend(b_keymap.into_iter());
-                Ok((TapTree::combine(a_tree, b_tree), a_keymap, $crate::keys::merge_networks(&a_networks, &b_networks)))
+                Ok((TapTree::Tree(Arc::new(a_tree), Arc::new(b_tree)), a_keymap, $crate::keys::merge_networks(&a_networks, &b_networks)))
            })

    }};
@@ -515,14 +516,13 @@ macro_rules! descriptor {
        use $crate::miniscript::descriptor::{Descriptor, DescriptorPublicKey};

        $crate::impl_top_level_pk!(Pkh, $crate::miniscript::Legacy, $key)
-            .and_then(|(a, b, c)| Ok((a.map_err(|e| miniscript::Error::from(e))?, b, c)))
            .map(|(a, b, c)| (Descriptor::<DescriptorPublicKey>::Pkh(a), b, c))
    });
    ( wpkh ( $key:expr ) ) => ({
        use $crate::miniscript::descriptor::{Descriptor, DescriptorPublicKey};

        $crate::impl_top_level_pk!(Wpkh, $crate::miniscript::Segwitv0, $key)
-            .and_then(|(a, b, c)| Ok((a.map_err(|e| miniscript::Error::from(e))?, b, c)))
+            .and_then(|(a, b, c)| Ok((a?, b, c)))
            .map(|(a, b, c)| (Descriptor::<DescriptorPublicKey>::Wpkh(a), b, c))
    });
    ( sh ( wpkh ( $key:expr ) ) ) => ({
@@ -532,7 +532,7 @@ macro_rules! descriptor {
        use $crate::miniscript::descriptor::{Descriptor, DescriptorPublicKey, Sh};

        $crate::impl_top_level_pk!(Wpkh, $crate::miniscript::Segwitv0, $key)
-            .and_then(|(a, b, c)| Ok((a.map_err(|e| miniscript::Error::from(e))?, b, c)))
+            .and_then(|(a, b, c)| Ok((a?, b, c)))
            .and_then(|(a, b, c)| Ok((Descriptor::<DescriptorPublicKey>::Sh(Sh::new_wpkh(a.into_inner())?), b, c)))
    });
    ( sh ( $( $minisc:tt )* ) ) => ({
@@ -702,7 +702,7 @@ macro_rules! fragment {
        $crate::keys::make_pkh($key, &secp)
    });
    ( after ( $value:expr ) ) => ({
-        $crate::impl_leaf_opcode_value!(After, $crate::miniscript::AbsLockTime::from_consensus($value))
+        $crate::impl_leaf_opcode_value!(After, $crate::bitcoin::PackedLockTime($value)) // TODO!! https://github.com/rust-bitcoin/rust-bitcoin/issues/1302
    });
    ( older ( $value:expr ) ) => ({
        $crate::impl_leaf_opcode_value!(Older, $crate::bitcoin::Sequence($value)) // TODO!!
@@ -796,6 +796,7 @@ macro_rules! fragment {
 #[cfg(test)]
 mod test {
    use alloc::string::ToString;
+    use bitcoin::hashes::hex::ToHex;
    use bitcoin::secp256k1::Secp256k1;
    use miniscript::descriptor::{DescriptorPublicKey, KeyMap};
    use miniscript::{Descriptor, Legacy, Segwitv0};
@@ -804,8 +805,8 @@ mod test {

    use crate::descriptor::{DescriptorError, DescriptorMeta};
    use crate::keys::{DescriptorKey, IntoDescriptorKey, ValidNetworks};
-    use bitcoin::bip32;
-    use bitcoin::Network::{Bitcoin, Regtest, Signet, Testnet};
+    use bitcoin::network::constants::Network::{Bitcoin, Regtest, Signet, Testnet};
+    use bitcoin::util::bip32;
    use bitcoin::PrivateKey;

    // test the descriptor!() macro
@@ -821,15 +822,18 @@ mod test {
        assert_eq!(desc.is_witness(), is_witness);
        assert_eq!(!desc.has_wildcard(), is_fixed);
        for i in 0..expected.len() {
-            let child_desc = desc
-                .at_derivation_index(i as u32)
-                .expect("i is not hardened");
+            let index = i as u32;
+            let child_desc = if !desc.has_wildcard() {
+                desc.at_derivation_index(0)
+            } else {
+                desc.at_derivation_index(index)
+            };
            let address = child_desc.address(Regtest);
            if let Ok(address) = address {
                assert_eq!(address.to_string(), *expected.get(i).unwrap());
            } else {
                let script = child_desc.script_pubkey();
-                assert_eq!(script.to_hex_string(), *expected.get(i).unwrap());
+                assert_eq!(script.to_hex().as_str(), *expected.get(i).unwrap());
            }
        }
    }
@@ -935,7 +939,7 @@ mod test {

    #[test]
    fn test_bip32_legacy_descriptors() {
-        let xprv = bip32::Xpriv::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
+        let xprv = bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();

        let path = bip32::DerivationPath::from_str("m/0").unwrap();
        let desc_key = (xprv, path.clone()).into_descriptor_key().unwrap();
@@ -980,7 +984,7 @@ mod test {

    #[test]
    fn test_bip32_segwitv0_descriptors() {
-        let xprv = bip32::Xpriv::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
+        let xprv = bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();

        let path = bip32::DerivationPath::from_str("m/0").unwrap();
        let desc_key = (xprv, path.clone()).into_descriptor_key().unwrap();
@@ -1037,10 +1041,10 @@ mod test {

    #[test]
    fn test_dsl_sortedmulti() {
-        let key_1 = bip32::Xpriv::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
+        let key_1 = bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
        let path_1 = bip32::DerivationPath::from_str("m/0").unwrap();

-        let key_2 = bip32::Xpriv::from_str("tprv8ZgxMBicQKsPegBHHnq7YEgM815dG24M2Jk5RVqipgDxF1HJ1tsnT815X5Fd5FRfMVUs8NZs9XCb6y9an8hRPThnhfwfXJ36intaekySHGF").unwrap();
+        let key_2 = bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPegBHHnq7YEgM815dG24M2Jk5RVqipgDxF1HJ1tsnT815X5Fd5FRfMVUs8NZs9XCb6y9an8hRPThnhfwfXJ36intaekySHGF").unwrap();
        let path_2 = bip32::DerivationPath::from_str("m/1").unwrap();

        let desc_key1 = (key_1, path_1);
@@ -1096,7 +1100,7 @@ mod test {
    // - verify the valid_networks returned is correctly computed based on the keys present in the descriptor
    #[test]
    fn test_valid_networks() {
-        let xprv = bip32::Xpriv::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
+        let xprv = bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
        let path = bip32::DerivationPath::from_str("m/0").unwrap();
        let desc_key = (xprv, path).into_descriptor_key().unwrap();

@@ -1106,7 +1110,7 @@ mod test {
            [Testnet, Regtest, Signet].iter().cloned().collect()
        );

-        let xprv = bip32::Xpriv::from_str("xprv9s21ZrQH143K3QTDL4LXw2F7HEK3wJUD2nW2nRk4stbPy6cq3jPPqjiChkVvvNKmPGJxWUtg6LnF5kejMRNNU3TGtRBeJgk33yuGBxrMPHi").unwrap();
+        let xprv = bip32::ExtendedPrivKey::from_str("xprv9s21ZrQH143K3QTDL4LXw2F7HEK3wJUD2nW2nRk4stbPy6cq3jPPqjiChkVvvNKmPGJxWUtg6LnF5kejMRNNU3TGtRBeJgk33yuGBxrMPHi").unwrap();
        let path = bip32::DerivationPath::from_str("m/10/20/30/40").unwrap();
        let desc_key = (xprv, path).into_descriptor_key().unwrap();

@@ -1119,15 +1123,15 @@ mod test {
    fn test_key_maps_merged() {
        let secp = Secp256k1::new();

-        let xprv1 = bip32::Xpriv::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
+        let xprv1 = bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
        let path1 = bip32::DerivationPath::from_str("m/0").unwrap();
        let desc_key1 = (xprv1, path1.clone()).into_descriptor_key().unwrap();

-        let xprv2 = bip32::Xpriv::from_str("tprv8ZgxMBicQKsPegBHHnq7YEgM815dG24M2Jk5RVqipgDxF1HJ1tsnT815X5Fd5FRfMVUs8NZs9XCb6y9an8hRPThnhfwfXJ36intaekySHGF").unwrap();
+        let xprv2 = bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPegBHHnq7YEgM815dG24M2Jk5RVqipgDxF1HJ1tsnT815X5Fd5FRfMVUs8NZs9XCb6y9an8hRPThnhfwfXJ36intaekySHGF").unwrap();
        let path2 = bip32::DerivationPath::from_str("m/2147483647'/0").unwrap();
        let desc_key2 = (xprv2, path2.clone()).into_descriptor_key().unwrap();

-        let xprv3 = bip32::Xpriv::from_str("tprv8ZgxMBicQKsPdZXrcHNLf5JAJWFAoJ2TrstMRdSKtEggz6PddbuSkvHKM9oKJyFgZV1B7rw8oChspxyYbtmEXYyg1AjfWbL3ho3XHDpHRZf").unwrap();
+        let xprv3 = bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPdZXrcHNLf5JAJWFAoJ2TrstMRdSKtEggz6PddbuSkvHKM9oKJyFgZV1B7rw8oChspxyYbtmEXYyg1AjfWbL3ho3XHDpHRZf").unwrap();
        let path3 = bip32::DerivationPath::from_str("m/10/20/30/40").unwrap();
        let desc_key3 = (xprv3, path3.clone()).into_descriptor_key().unwrap();

@@ -1151,7 +1155,7 @@ mod test {
    #[test]
    fn test_script_context_validation() {
        // this compiles
-        let xprv = bip32::Xpriv::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
+        let xprv = bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
        let path = bip32::DerivationPath::from_str("m/0").unwrap();
        let desc_key: DescriptorKey<Legacy> = (xprv, path).into_descriptor_key().unwrap();

@@ -1174,7 +1178,9 @@ mod test {
    }

    #[test]
-    #[should_panic(expected = "Miniscript(ContextError(UncompressedKeysNotAllowed))")]
+    #[should_panic(
+        expected = "Miniscript(ContextError(CompressedOnly(\"04b4632d08485ff1df2db55b9dafd23347d1c47a457072a1e87be26896549a87378ec38ff91d43e8c2092ebda601780485263da089465619e0358a5c1be7ac91f4\")))"
+    )]
    fn test_dsl_miniscript_checks() {
        let mut uncompressed_pk =
            PrivateKey::from_wif("L5EZftvrYaSudiozVRzTqLcHLNDoVn7H5HSfM9BAN6tMJX8oTWz6").unwrap();
--- a/crates/bdk/src/descriptor/error.rs
+++ b/crates/bdk/src/descriptor/error.rs
@@ -10,7 +10,6 @@
 // licenses.

 //! Descriptor errors
-use core::fmt;

 /// Errors related to the parsing and usage of descriptors
 #[derive(Debug)]
@@ -21,8 +20,6 @@ pub enum Error {
    InvalidDescriptorChecksum,
    /// The descriptor contains hardened derivation steps on public extended keys
    HardenedDerivationXpub,
-    /// The descriptor contains multipath keys
-    MultiPath,

    /// Error thrown while working with [`keys`](crate::keys)
    Key(crate::keys::KeyError),
@@ -33,15 +30,15 @@ pub enum Error {
    InvalidDescriptorCharacter(u8),

    /// BIP32 error
-    Bip32(bitcoin::bip32::Error),
+    Bip32(bitcoin::util::bip32::Error),
    /// Error during base58 decoding
-    Base58(bitcoin::base58::Error),
+    Base58(bitcoin::util::base58::Error),
    /// Key-related error
-    Pk(bitcoin::key::Error),
+    Pk(bitcoin::util::key::Error),
    /// Miniscript error
    Miniscript(miniscript::Error),
    /// Hex decoding error
-    Hex(bitcoin::hex::HexToBytesError),
+    Hex(bitcoin::hashes::hex::Error),
 }

 impl From<crate::keys::KeyError> for Error {
@@ -54,8 +51,8 @@ impl From<crate::keys::KeyError> for Error {
    }
 }

-impl fmt::Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::InvalidHdKeyPath => write!(f, "Invalid HD key path"),
            Self::InvalidDescriptorChecksum => {
@@ -65,10 +62,6 @@ impl fmt::Display for Error {
                f,
                "The descriptor contains hardened derivation steps on public extended keys"
            ),
-            Self::MultiPath => write!(
-                f,
-                "The descriptor contains multipath keys, which are not supported yet"
-            ),
            Self::Key(err) => write!(f, "Key error: {}", err),
            Self::Policy(err) => write!(f, "Policy error: {}", err),
            Self::InvalidDescriptorCharacter(char) => {
@@ -86,38 +79,9 @@ impl fmt::Display for Error {
 #[cfg(feature = "std")]
 impl std::error::Error for Error {}

-impl From<bitcoin::bip32::Error> for Error {
-    fn from(err: bitcoin::bip32::Error) -> Self {
-        Error::Bip32(err)
-    }
-}
-
-impl From<bitcoin::base58::Error> for Error {
-    fn from(err: bitcoin::base58::Error) -> Self {
-        Error::Base58(err)
-    }
-}
-
-impl From<bitcoin::key::Error> for Error {
-    fn from(err: bitcoin::key::Error) -> Self {
-        Error::Pk(err)
-    }
-}
-
-impl From<miniscript::Error> for Error {
-    fn from(err: miniscript::Error) -> Self {
-        Error::Miniscript(err)
-    }
-}
-
-impl From<bitcoin::hex::HexToBytesError> for Error {
-    fn from(err: bitcoin::hex::HexToBytesError) -> Self {
-        Error::Hex(err)
-    }
-}
-
-impl From<crate::descriptor::policy::PolicyError> for Error {
-    fn from(err: crate::descriptor::policy::PolicyError) -> Self {
-        Error::Policy(err)
-    }
-}
+impl_error!(bitcoin::util::bip32::Error, Bip32);
+impl_error!(bitcoin::util::base58::Error, Base58);
+impl_error!(bitcoin::util::key::Error, Pk);
+impl_error!(miniscript::Error, Miniscript);
+impl_error!(bitcoin::hashes::hex::Error, Hex);
+impl_error!(crate::descriptor::policy::PolicyError, Policy);
--- a/crates/bdk/src/descriptor/mod.rs
+++ b/crates/bdk/src/descriptor/mod.rs
@@ -18,17 +18,17 @@ use crate::collections::BTreeMap;
 use alloc::string::String;
 use alloc::vec::Vec;

-use bitcoin::bip32::{ChildNumber, DerivationPath, Fingerprint, KeySource, Xpub};
-use bitcoin::{key::XOnlyPublicKey, secp256k1, PublicKey};
-use bitcoin::{psbt, taproot};
+use bitcoin::util::bip32::{ChildNumber, DerivationPath, ExtendedPubKey, Fingerprint, KeySource};
+use bitcoin::util::{psbt, taproot};
+use bitcoin::{secp256k1, PublicKey, XOnlyPublicKey};
 use bitcoin::{Network, TxOut};

 use miniscript::descriptor::{
-    DefiniteDescriptorKey, DescriptorMultiXKey, DescriptorSecretKey, DescriptorType,
-    DescriptorXKey, InnerXKey, KeyMap, SinglePubKey, Wildcard,
+    DefiniteDescriptorKey, DescriptorSecretKey, DescriptorType, InnerXKey, SinglePubKey,
 };
 pub use miniscript::{
-    Descriptor, DescriptorPublicKey, Legacy, Miniscript, ScriptContext, Segwitv0,
+    descriptor::DescriptorXKey, descriptor::KeyMap, descriptor::Wildcard, Descriptor,
+    DescriptorPublicKey, Legacy, Miniscript, ScriptContext, Segwitv0,
 };
 use miniscript::{ForEachKey, MiniscriptKey, TranslatePk};

@@ -59,16 +59,16 @@ pub type DerivedDescriptor = Descriptor<DefiniteDescriptorKey>;
 /// Alias for the type of maps that represent derivation paths in a [`psbt::Input`] or
 /// [`psbt::Output`]
 ///
-/// [`psbt::Input`]: bitcoin::psbt::Input
-/// [`psbt::Output`]: bitcoin::psbt::Output
+/// [`psbt::Input`]: bitcoin::util::psbt::Input
+/// [`psbt::Output`]: bitcoin::util::psbt::Output
 pub type HdKeyPaths = BTreeMap<secp256k1::PublicKey, KeySource>;

 /// Alias for the type of maps that represent taproot key origins in a [`psbt::Input`] or
 /// [`psbt::Output`]
 ///
-/// [`psbt::Input`]: bitcoin::psbt::Input
-/// [`psbt::Output`]: bitcoin::psbt::Output
-pub type TapKeyOrigins = BTreeMap<XOnlyPublicKey, (Vec<taproot::TapLeafHash>, KeySource)>;
+/// [`psbt::Input`]: bitcoin::util::psbt::Input
+/// [`psbt::Output`]: bitcoin::util::psbt::Output
+pub type TapKeyOrigins = BTreeMap<bitcoin::XOnlyPublicKey, (Vec<taproot::TapLeafHash>, KeySource)>;

 /// Trait for types which can be converted into an [`ExtendedDescriptor`] and a [`KeyMap`] usable by a wallet in a specific [`Network`]
 pub trait IntoWalletDescriptor {
@@ -136,10 +136,14 @@ impl IntoWalletDescriptor for (ExtendedDescriptor, KeyMap) {
            network: Network,
        }

-        impl<'s, 'd> miniscript::Translator<DescriptorPublicKey, String, DescriptorError>
+        impl<'s, 'd>
+            miniscript::Translator<DescriptorPublicKey, miniscript::DummyKey, DescriptorError>
            for Translator<'s, 'd>
        {
-            fn pk(&mut self, pk: &DescriptorPublicKey) -> Result<String, DescriptorError> {
+            fn pk(
+                &mut self,
+                pk: &DescriptorPublicKey,
+            ) -> Result<miniscript::DummyKey, DescriptorError> {
                let secp = &self.secp;

                let (_, _, networks) = if self.descriptor.is_taproot() {
@@ -157,7 +161,7 @@ impl IntoWalletDescriptor for (ExtendedDescriptor, KeyMap) {
                };

                if networks.contains(&self.network) {
-                    Ok(Default::default())
+                    Ok(miniscript::DummyKey)
                } else {
                    Err(DescriptorError::Key(KeyError::InvalidNetwork))
                }
@@ -165,40 +169,35 @@ impl IntoWalletDescriptor for (ExtendedDescriptor, KeyMap) {
            fn sha256(
                &mut self,
                _sha256: &<DescriptorPublicKey as MiniscriptKey>::Sha256,
-            ) -> Result<String, DescriptorError> {
+            ) -> Result<miniscript::DummySha256Hash, DescriptorError> {
                Ok(Default::default())
            }
            fn hash256(
                &mut self,
                _hash256: &<DescriptorPublicKey as MiniscriptKey>::Hash256,
-            ) -> Result<String, DescriptorError> {
+            ) -> Result<miniscript::DummyHash256Hash, DescriptorError> {
                Ok(Default::default())
            }
            fn ripemd160(
                &mut self,
                _ripemd160: &<DescriptorPublicKey as MiniscriptKey>::Ripemd160,
-            ) -> Result<String, DescriptorError> {
+            ) -> Result<miniscript::DummyRipemd160Hash, DescriptorError> {
                Ok(Default::default())
            }
            fn hash160(
                &mut self,
                _hash160: &<DescriptorPublicKey as MiniscriptKey>::Hash160,
-            ) -> Result<String, DescriptorError> {
+            ) -> Result<miniscript::DummyHash160Hash, DescriptorError> {
                Ok(Default::default())
            }
        }

        // check the network for the keys
-        use miniscript::TranslateErr;
-        match self.0.translate_pk(&mut Translator {
+        self.0.translate_pk(&mut Translator {
            secp,
            network,
            descriptor: &self.0,
-        }) {
-            Ok(_) => {}
-            Err(TranslateErr::TranslatorErr(e)) => return Err(e),
-            Err(TranslateErr::OuterError(e)) => return Err(e.into()),
-        }
+        })?;

        Ok(self)
    }
@@ -252,12 +251,7 @@ impl IntoWalletDescriptor for DescriptorTemplateOut {
        }

        // fixup the network for keys that need it in the descriptor
-        use miniscript::TranslateErr;
-        let translated = match desc.translate_pk(&mut Translator { network }) {
-            Ok(descriptor) => descriptor,
-            Err(TranslateErr::TranslatorErr(e)) => return Err(e),
-            Err(TranslateErr::OuterError(e)) => return Err(e.into()),
-        };
+        let translated = desc.translate_pk(&mut Translator { network })?;
        // ...and in the key map
        let fixed_keymap = keymap
            .into_iter()
@@ -308,10 +302,6 @@ pub(crate) fn into_wallet_descriptor_checked<T: IntoWalletDescriptor>(
        return Err(DescriptorError::HardenedDerivationXpub);
    }

-    if descriptor.is_multipath() {
-        return Err(DescriptorError::MultiPath);
-    }
-
    // Run miniscript's sanity check, which will look for duplicated keys and other potential
    // issues
    descriptor.sanity_check()?;
@@ -350,18 +340,6 @@ pub(crate) trait XKeyUtils {
    fn root_fingerprint(&self, secp: &SecpCtx) -> Fingerprint;
 }

-impl<T> XKeyUtils for DescriptorMultiXKey<T>
-where
-    T: InnerXKey,
-{
-    fn root_fingerprint(&self, secp: &SecpCtx) -> Fingerprint {
-        match self.origin {
-            Some((fingerprint, _)) => fingerprint,
-            None => self.xkey.xkey_fingerprint(secp),
-        }
-    }
-}
-
 impl<T> XKeyUtils for DescriptorXKey<T>
 where
    T: InnerXKey,
@@ -377,7 +355,7 @@ where
 pub(crate) trait DescriptorMeta {
    fn is_witness(&self) -> bool;
    fn is_taproot(&self) -> bool;
-    fn get_extended_keys(&self) -> Vec<DescriptorXKey<Xpub>>;
+    fn get_extended_keys(&self) -> Vec<DescriptorXKey<ExtendedPubKey>>;
    fn derive_from_hd_keypaths(
        &self,
        hd_keypaths: &HdKeyPaths,
@@ -418,7 +396,7 @@ impl DescriptorMeta for ExtendedDescriptor {
        self.desc_type() == DescriptorType::Tr
    }

-    fn get_extended_keys(&self) -> Vec<DescriptorXKey<Xpub>> {
+    fn get_extended_keys(&self) -> Vec<DescriptorXKey<ExtendedPubKey>> {
        let mut answer = Vec::new();

        self.for_each_key(|pk| {
@@ -438,20 +416,21 @@ impl DescriptorMeta for ExtendedDescriptor {
        secp: &SecpCtx,
    ) -> Option<DerivedDescriptor> {
        // Ensure that deriving `xpub` with `path` yields `expected`
-        let verify_key =
-            |xpub: &DescriptorXKey<Xpub>, path: &DerivationPath, expected: &SinglePubKey| {
-                let derived = xpub
-                    .xkey
-                    .derive_pub(secp, path)
-                    .expect("The path should never contain hardened derivation steps")
-                    .public_key;
+        let verify_key = |xpub: &DescriptorXKey<ExtendedPubKey>,
+                          path: &DerivationPath,
+                          expected: &SinglePubKey| {
+            let derived = xpub
+                .xkey
+                .derive_pub(secp, path)
+                .expect("The path should never contain hardened derivation steps")
+                .public_key;

-                match expected {
-                    SinglePubKey::FullKey(pk) if &PublicKey::new(derived) == pk => true,
-                    SinglePubKey::XOnly(pk) if &XOnlyPublicKey::from(derived) == pk => true,
-                    _ => false,
-                }
-            };
+            match expected {
+                SinglePubKey::FullKey(pk) if &PublicKey::new(derived) == pk => true,
+                SinglePubKey::XOnly(pk) if &XOnlyPublicKey::from(derived) == pk => true,
+                _ => false,
+            }
+        };

        let mut path_found = None;

@@ -487,6 +466,11 @@ impl DescriptorMeta for ExtendedDescriptor {
                        ) {
                            Some(derive_path)
                        } else {
+                            log::debug!(
+                                "Key `{}` derived with {} yields an unexpected key",
+                                root_fingerprint,
+                                derive_path
+                            );
                            None
                        }
                    });
@@ -510,10 +494,7 @@ impl DescriptorMeta for ExtendedDescriptor {
            false
        });

-        path_found.map(|path| {
-            self.at_derivation_index(path)
-                .expect("We ignore hardened wildcards")
-        })
+        path_found.map(|path| self.at_derivation_index(path))
    }

    fn derive_from_hd_keypaths(
@@ -564,7 +545,7 @@ impl DescriptorMeta for ExtendedDescriptor {
            return None;
        }

-        let descriptor = self.at_derivation_index(0).expect("0 is not hardened");
+        let descriptor = self.at_derivation_index(0);
        match descriptor.desc_type() {
            // TODO: add pk() here
            DescriptorType::Pkh
@@ -604,10 +585,11 @@ mod test {
    use core::str::FromStr;

    use assert_matches::assert_matches;
-    use bitcoin::hex::FromHex;
+    use bitcoin::consensus::encode::deserialize;
+    use bitcoin::hashes::hex::FromHex;
    use bitcoin::secp256k1::Secp256k1;
-    use bitcoin::ScriptBuf;
-    use bitcoin::{bip32, Psbt};
+    use bitcoin::util::{bip32, psbt};
+    use bitcoin::Script;

    use super::*;
    use crate::psbt::PsbtUtils;
@@ -618,7 +600,7 @@ mod test {
            "wpkh(02b4632d08485ff1df2db55b9dafd23347d1c47a457072a1e87be26896549a8737)",
        )
        .unwrap();
-        let psbt = Psbt::deserialize(
+        let psbt: psbt::PartiallySignedTransaction = deserialize(
            &Vec::<u8>::from_hex(
                "70736274ff010052010000000162307be8e431fbaff807cdf9cdc3fde44d7402\
                 11bc8342c31ffd6ec11fe35bcc0100000000ffffffff01328601000000000016\
@@ -641,7 +623,7 @@ mod test {
            "pkh([0f056943/44h/0h/0h]tpubDDpWvmUrPZrhSPmUzCMBHffvC3HyMAPnWDSAQNBTnj1iZeJa7BZQEttFiP4DS4GCcXQHezdXhn86Hj6LHX5EDstXPWrMaSneRWM8yUf6NFd/10/*)",
        )
        .unwrap();
-        let psbt = Psbt::deserialize(
+        let psbt: psbt::PartiallySignedTransaction = deserialize(
            &Vec::<u8>::from_hex(
                "70736274ff010053010000000145843b86be54a3cd8c9e38444e1162676c00df\
                 e7964122a70df491ea12fd67090100000000ffffffff01c19598000000000017\
@@ -672,7 +654,7 @@ mod test {
            "wsh(and_v(v:pk(03b6633fef2397a0a9de9d7b6f23aef8368a6e362b0581f0f0af70d5ecfd254b14),older(6)))",
        )
        .unwrap();
-        let psbt = Psbt::deserialize(
+        let psbt: psbt::PartiallySignedTransaction = deserialize(
            &Vec::<u8>::from_hex(
                "70736274ff01005302000000011c8116eea34408ab6529223c9a176606742207\
                 67a1ff1d46a6e3c4a88243ea6e01000000000600000001109698000000000017\
@@ -696,7 +678,7 @@ mod test {
            "sh(and_v(v:pk(021403881a5587297818fcaf17d239cefca22fce84a45b3b1d23e836c4af671dbb),after(630000)))",
        )
        .unwrap();
-        let psbt = Psbt::deserialize(
+        let psbt: psbt::PartiallySignedTransaction = deserialize(
            &Vec::<u8>::from_hex(
                "70736274ff0100530100000001bc8c13df445dfadcc42afa6dc841f85d22b01d\
                 a6270ebf981740f4b7b1d800390000000000feffffff01ba9598000000000017\
@@ -726,7 +708,7 @@ mod test {

        let secp = Secp256k1::new();

-        let xprv = bip32::Xpriv::from_str("xprv9s21ZrQH143K3c3gF1DUWpWNr2SG2XrG8oYPpqYh7hoWsJy9NjabErnzriJPpnGHyKz5NgdXmq1KVbqS1r4NXdCoKitWg5e86zqXHa8kxyB").unwrap();
+        let xprv = bip32::ExtendedPrivKey::from_str("xprv9s21ZrQH143K3c3gF1DUWpWNr2SG2XrG8oYPpqYh7hoWsJy9NjabErnzriJPpnGHyKz5NgdXmq1KVbqS1r4NXdCoKitWg5e86zqXHa8kxyB").unwrap();
        let path = bip32::DerivationPath::from_str("m/0").unwrap();

        // here `to_descriptor_key` will set the valid networks for the key to only mainnet, since
@@ -745,7 +727,7 @@ mod test {
        let mut xprv_testnet = xprv;
        xprv_testnet.network = Network::Testnet;

-        let xpub_testnet = bip32::Xpub::from_priv(&secp, &xprv_testnet);
+        let xpub_testnet = bip32::ExtendedPubKey::from_priv(&secp, &xprv_testnet);
        let desc_pubkey = DescriptorPublicKey::XPub(DescriptorXKey {
            xkey: xpub_testnet,
            origin: None,
@@ -835,7 +817,7 @@ mod test {
    fn test_descriptor_from_str_from_output_of_macro() {
        let secp = Secp256k1::new();

-        let tpub = bip32::Xpub::from_str("tpubD6NzVbkrYhZ4XHndKkuB8FifXm8r5FQHwrN6oZuWCz13qb93rtgKvD4PQsqC4HP4yhV3tA2fqr2RbY5mNXfM7RxXUoeABoDtsFUq2zJq6YK").unwrap();
+        let tpub = bip32::ExtendedPubKey::from_str("tpubD6NzVbkrYhZ4XHndKkuB8FifXm8r5FQHwrN6oZuWCz13qb93rtgKvD4PQsqC4HP4yhV3tA2fqr2RbY5mNXfM7RxXUoeABoDtsFUq2zJq6YK").unwrap();
        let path = bip32::DerivationPath::from_str("m/1/2").unwrap();
        let key = (tpub, path).into_descriptor_key().unwrap();

@@ -863,12 +845,6 @@ mod test {

        assert_matches!(result, Err(DescriptorError::HardenedDerivationXpub));

-        let descriptor = "wpkh(tpubD6NzVbkrYhZ4XHndKkuB8FifXm8r5FQHwrN6oZuWCz13qb93rtgKvD4PQsqC4HP4yhV3tA2fqr2RbY5mNXfM7RxXUoeABoDtsFUq2zJq6YK/<0;1>/*)";
-        let result = into_wallet_descriptor_checked(descriptor, &secp, Network::Testnet);
-
-        assert_matches!(result, Err(DescriptorError::MultiPath));
-
-        // repeated pubkeys
        let descriptor = "wsh(multi(2,tpubD6NzVbkrYhZ4XHndKkuB8FifXm8r5FQHwrN6oZuWCz13qb93rtgKvD4PQsqC4HP4yhV3tA2fqr2RbY5mNXfM7RxXUoeABoDtsFUq2zJq6YK/0/*,tpubD6NzVbkrYhZ4XHndKkuB8FifXm8r5FQHwrN6oZuWCz13qb93rtgKvD4PQsqC4HP4yhV3tA2fqr2RbY5mNXfM7RxXUoeABoDtsFUq2zJq6YK/0/*))";
        let result = into_wallet_descriptor_checked(descriptor, &secp, Network::Testnet);

@@ -885,16 +861,16 @@ mod test {
        let (descriptor, _) =
            into_wallet_descriptor_checked(descriptor, &secp, Network::Testnet).unwrap();

-        let descriptor = descriptor.at_derivation_index(0).unwrap();
+        let descriptor = descriptor.at_derivation_index(0);

-        let script = ScriptBuf::from_hex("5321022f533b667e2ea3b36e21961c9fe9dca340fbe0af5210173a83ae0337ab20a57621026bb53a98e810bd0ee61a0ed1164ba6c024786d76554e793e202dc6ce9c78c4ea2102d5b8a7d66a41ffdb6f4c53d61994022e886b4f45001fb158b95c9164d45f8ca3210324b75eead2c1f9c60e8adeb5e7009fec7a29afcdb30d829d82d09562fe8bae8521032d34f8932200833487bd294aa219dcbe000b9f9b3d824799541430009f0fa55121037468f8ea99b6c64788398b5ad25480cad08f4b0d65be54ce3a55fd206b5ae4722103f72d3d96663b0ea99b0aeb0d7f273cab11a8de37885f1dddc8d9112adb87169357ae").unwrap();
+        let script = Script::from_str("5321022f533b667e2ea3b36e21961c9fe9dca340fbe0af5210173a83ae0337ab20a57621026bb53a98e810bd0ee61a0ed1164ba6c024786d76554e793e202dc6ce9c78c4ea2102d5b8a7d66a41ffdb6f4c53d61994022e886b4f45001fb158b95c9164d45f8ca3210324b75eead2c1f9c60e8adeb5e7009fec7a29afcdb30d829d82d09562fe8bae8521032d34f8932200833487bd294aa219dcbe000b9f9b3d824799541430009f0fa55121037468f8ea99b6c64788398b5ad25480cad08f4b0d65be54ce3a55fd206b5ae4722103f72d3d96663b0ea99b0aeb0d7f273cab11a8de37885f1dddc8d9112adb87169357ae").unwrap();

        let mut psbt_input = psbt::Input::default();
        psbt_input
            .update_with_descriptor_unchecked(&descriptor)
            .unwrap();

-        assert_eq!(psbt_input.redeem_script, Some(script.to_p2wsh()));
+        assert_eq!(psbt_input.redeem_script, Some(script.to_v0_p2wsh()));
        assert_eq!(psbt_input.witness_script, Some(script));
    }
 }
--- a/crates/bdk/src/descriptor/policy.rs
+++ b/crates/bdk/src/descriptor/policy.rs
@@ -33,22 +33,21 @@
 //! let signers = Arc::new(SignersContainer::build(key_map, &extended_desc, &secp));
 //! let policy = extended_desc.extract_policy(&signers, BuildSatisfaction::None, &secp)?;
 //! println!("policy: {}", serde_json::to_string(&policy).unwrap());
-//! # Ok::<(), anyhow::Error>(())
+//! # Ok::<(), bdk::Error>(())
 //! ```

 use crate::collections::{BTreeMap, HashSet, VecDeque};
 use alloc::string::String;
 use alloc::vec::Vec;
 use core::cmp::max;
-
 use core::fmt;

 use serde::ser::SerializeMap;
 use serde::{Serialize, Serializer};

-use bitcoin::bip32::Fingerprint;
 use bitcoin::hashes::{hash160, ripemd160, sha256};
-use bitcoin::{absolute, key::XOnlyPublicKey, PublicKey, Sequence};
+use bitcoin::util::bip32::Fingerprint;
+use bitcoin::{LockTime, PublicKey, Sequence, XOnlyPublicKey};

 use miniscript::descriptor::{
    DescriptorPublicKey, ShInner, SinglePub, SinglePubKey, SortedMultiVec, WshInner,
@@ -58,6 +57,9 @@ use miniscript::{
    Descriptor, Miniscript, Satisfier, ScriptContext, SigType, Terminal, ToPublicKey,
 };

+#[allow(unused_imports)]
+use log::{debug, error, info, trace};
+
 use crate::descriptor::ExtractPolicy;
 use crate::keys::ExtScriptContext;
 use crate::wallet::signer::{SignerId, SignersContainer};
@@ -66,7 +68,7 @@ use crate::wallet::utils::{After, Older, SecpCtx};
 use super::checksum::calc_checksum;
 use super::error::Error;
 use super::XKeyUtils;
-use bitcoin::psbt::{self, Psbt};
+use bitcoin::util::psbt::{Input as PsbtInput, PartiallySignedTransaction as Psbt};
 use miniscript::psbt::PsbtInputSatisfier;

 /// A unique identifier for a key
@@ -93,9 +95,6 @@ impl PkOrF {
                ..
            }) => PkOrF::XOnlyPubkey(*pk),
            DescriptorPublicKey::XPub(xpub) => PkOrF::Fingerprint(xpub.root_fingerprint(secp)),
-            DescriptorPublicKey::MultiXPub(multi) => {
-                PkOrF::Fingerprint(multi.root_fingerprint(secp))
-            }
        }
    }
 }
@@ -132,7 +131,7 @@ pub enum SatisfiableItem {
    /// Absolute timeclock timestamp
    AbsoluteTimelock {
        /// The timelock value
-        value: absolute::LockTime,
+        value: LockTime,
    },
    /// Relative timelock locktime
    RelativeTimelock {
@@ -452,14 +451,11 @@ pub struct Condition {
    pub csv: Option<Sequence>,
    /// Optional timelock condition
    #[serde(skip_serializing_if = "Option::is_none")]
-    pub timelock: Option<absolute::LockTime>,
+    pub timelock: Option<LockTime>,
 }

 impl Condition {
-    fn merge_nlocktime(
-        a: absolute::LockTime,
-        b: absolute::LockTime,
-    ) -> Result<absolute::LockTime, PolicyError> {
+    fn merge_nlocktime(a: LockTime, b: LockTime) -> Result<LockTime, PolicyError> {
        if !a.is_same_unit(b) {
            Err(PolicyError::MixedTimelockUnits)
        } else if a > b {
@@ -519,7 +515,7 @@ pub enum PolicyError {
 impl fmt::Display for PolicyError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
-            Self::NotEnoughItemsSelected(err) => write!(f, "Not enough items selected: {}", err),
+            Self::NotEnoughItemsSelected(err) => write!(f, "Not enought items selected: {}", err),
            Self::IndexOutOfRange(index) => write!(f, "Index out of range: {}", index),
            Self::AddOnLeaf => write!(f, "Add on leaf"),
            Self::AddOnPartialComplete => write!(f, "Add on partial complete"),
@@ -666,11 +662,11 @@ impl Policy {
                (0..*threshold).collect()
            }
            SatisfiableItem::Multisig { keys, .. } => (0..keys.len()).collect(),
-            _ => HashSet::new(),
+            _ => vec![],
        };
-        let selected: HashSet<_> = match path.get(&self.id) {
-            Some(arr) => arr.iter().copied().collect(),
-            _ => default,
+        let selected = match path.get(&self.id) {
+            Some(arr) => arr,
+            _ => &default,
        };

        match &self.item {
@@ -678,24 +674,14 @@ impl Policy {
                let mapped_req = items
                    .iter()
                    .map(|i| i.get_condition(path))
-                    .collect::<Vec<_>>();
+                    .collect::<Result<Vec<_>, _>>()?;

                // if all the requirements are null we don't care about `selected` because there
                // are no requirements
-                if mapped_req
-                    .iter()
-                    .all(|cond| matches!(cond, Ok(c) if c.is_null()))
-                {
+                if mapped_req.iter().all(Condition::is_null) {
                    return Ok(Condition::default());
                }

-                // make sure all the indexes in the `selected` list are within range
-                for index in &selected {
-                    if *index >= items.len() {
-                        return Err(PolicyError::IndexOutOfRange(*index));
-                    }
-                }
-
                // if we have something, make sure we have enough items. note that the user can set
                // an empty value for this step in case of n-of-n, because `selected` is set to all
                // the elements above
@@ -704,18 +690,23 @@ impl Policy {
                }

                // check the selected items, see if there are conflicting requirements
-                mapped_req
-                    .into_iter()
-                    .enumerate()
-                    .filter(|(index, _)| selected.contains(index))
-                    .try_fold(Condition::default(), |acc, (_, cond)| acc.merge(&cond?))
+                let mut requirements = Condition::default();
+                for item_index in selected {
+                    requirements = requirements.merge(
+                        mapped_req
+                            .get(*item_index)
+                            .ok_or(PolicyError::IndexOutOfRange(*item_index))?,
+                    )?;
+                }
+
+                Ok(requirements)
            }
            SatisfiableItem::Multisig { keys, threshold } => {
                if selected.len() < *threshold {
                    return Err(PolicyError::NotEnoughItemsSelected(self.id.clone()));
                }
-                if let Some(item) = selected.into_iter().find(|&i| i >= keys.len()) {
-                    return Err(PolicyError::IndexOutOfRange(item));
+                if let Some(item) = selected.iter().find(|i| **i >= keys.len()) {
+                    return Err(PolicyError::IndexOutOfRange(*item));
                }

                Ok(Condition::default())
@@ -753,7 +744,6 @@ fn signer_id(key: &DescriptorPublicKey, secp: &SecpCtx) -> SignerId {
            ..
        }) => pk.to_pubkeyhash(SigType::Ecdsa).into(),
        DescriptorPublicKey::XPub(xpub) => xpub.root_fingerprint(secp).into(),
-        DescriptorPublicKey::MultiXPub(xpub) => xpub.root_fingerprint(secp).into(),
    }
 }

@@ -791,9 +781,9 @@ fn make_generic_signature<M: Fn() -> SatisfiableItem, F: Fn(&Psbt) -> bool>(
 fn generic_sig_in_psbt<
    // C is for "check", it's a closure we use to *check* if a psbt input contains the signature
    // for a specific key
-    C: Fn(&psbt::Input, &SinglePubKey) -> bool,
+    C: Fn(&PsbtInput, &SinglePubKey) -> bool,
    // E is for "extract", it extracts a key from the bip32 derivations found in the psbt input
-    E: Fn(&psbt::Input, Fingerprint) -> Option<SinglePubKey>,
+    E: Fn(&PsbtInput, Fingerprint) -> Option<SinglePubKey>,
 >(
    psbt: &Psbt,
    key: &DescriptorPublicKey,
@@ -811,13 +801,6 @@ fn generic_sig_in_psbt<
                None => false,
            }
        }
-        DescriptorPublicKey::MultiXPub(xpub) => {
-            //TODO check actual derivation matches
-            match extract(input, xpub.root_fingerprint(secp)) {
-                Some(pubkey) => check(input, &pubkey),
-                None => false,
-            }
-        }
    })
 }

@@ -923,12 +906,12 @@ impl<Ctx: ScriptContext + 'static> ExtractPolicy for Miniscript<DescriptorPublic
            }
            Terminal::After(value) => {
                let mut policy: Policy = SatisfiableItem::AbsoluteTimelock {
-                    value: (*value).into(),
+                    value: value.into(),
                }
                .into();
                policy.contribution = Satisfaction::Complete {
                    condition: Condition {
-                        timelock: Some((*value).into()),
+                        timelock: Some(value.into()),
                        csv: None,
                    },
                };
@@ -940,9 +923,9 @@ impl<Ctx: ScriptContext + 'static> ExtractPolicy for Miniscript<DescriptorPublic
                {
                    let after = After::new(Some(current_height), false);
                    let after_sat =
-                        Satisfier::<bitcoin::PublicKey>::check_after(&after, (*value).into());
+                        Satisfier::<bitcoin::PublicKey>::check_after(&after, value.into());
                    let inputs_sat = psbt_inputs_sat(psbt).all(|sat| {
-                        Satisfier::<bitcoin::PublicKey>::check_after(&sat, (*value).into())
+                        Satisfier::<bitcoin::PublicKey>::check_after(&sat, value.into())
                    });
                    if after_sat && inputs_sat {
                        policy.satisfaction = policy.contribution.clone();
@@ -1137,7 +1120,7 @@ impl ExtractPolicy for Descriptor<DescriptorPublicKey> {
                let key_spend_sig =
                    miniscript::Tap::make_signature(tr.internal_key(), signers, build_sat, secp);

-                if tr.tap_tree().is_none() {
+                if tr.taptree().is_none() {
                    Ok(Some(key_spend_sig))
                } else {
                    let mut items = vec![key_spend_sig];
@@ -1168,8 +1151,8 @@ mod test {
    use crate::wallet::signer::SignersContainer;
    use alloc::{string::ToString, sync::Arc};
    use assert_matches::assert_matches;
-    use bitcoin::bip32;
    use bitcoin::secp256k1::Secp256k1;
+    use bitcoin::util::bip32;
    use bitcoin::Network;
    use core::str::FromStr;

@@ -1184,8 +1167,8 @@ mod test {
        secp: &SecpCtx,
    ) -> (DescriptorKey<Ctx>, DescriptorKey<Ctx>, Fingerprint) {
        let path = bip32::DerivationPath::from_str(path).unwrap();
-        let tprv = bip32::Xpriv::from_str(tprv).unwrap();
-        let tpub = bip32::Xpub::from_priv(secp, &tprv);
+        let tprv = bip32::ExtendedPrivKey::from_str(tprv).unwrap();
+        let tpub = bip32::ExtendedPubKey::from_priv(secp, &tprv);
        let fingerprint = tprv.fingerprint(secp);
        let prvkey = (tprv, path.clone()).into_descriptor_key().unwrap();
        let pubkey = (tpub, path).into_descriptor_key().unwrap();
@@ -1587,7 +1570,6 @@ mod test {

        let addr = wallet_desc
            .at_derivation_index(0)
-            .unwrap()
            .address(Network::Testnet)
            .unwrap();
        assert_eq!(
@@ -1654,7 +1636,6 @@ mod test {

        let addr = wallet_desc
            .at_derivation_index(0)
-            .unwrap()
            .address(Network::Testnet)
            .unwrap();
        assert_eq!(
--- a/crates/bdk/src/descriptor/template.rs
+++ b/crates/bdk/src/descriptor/template.rs
@@ -14,10 +14,10 @@
 //! This module contains the definition of various common script templates that are ready to be
 //! used. See the documentation of each template for an example.

-use bitcoin::bip32;
+use bitcoin::util::bip32;
 use bitcoin::Network;

-use miniscript::{Legacy, Segwitv0, Tap};
+use miniscript::{Legacy, Segwitv0};

 use super::{ExtendedDescriptor, IntoWalletDescriptor, KeyMap};
 use crate::descriptor::DescriptorError;
@@ -152,34 +152,6 @@ impl<K: IntoDescriptorKey<Segwitv0>> DescriptorTemplate for P2Wpkh<K> {
    }
 }

-/// P2TR template. Expands to a descriptor `tr(key)`
-///
-/// ## Example
-///
-/// ```
-/// # use bdk::bitcoin::{PrivateKey, Network};
-/// # use bdk::Wallet;
-/// # use bdk::wallet::AddressIndex::New;
-/// use bdk::template::P2TR;
-///
-/// let key =
-///     bitcoin::PrivateKey::from_wif("cTc4vURSzdx6QE6KVynWGomDbLaA75dNALMNyfjh3p8DRRar84Um")?;
-/// let mut wallet = Wallet::new_no_persist(P2TR(key), None, Network::Testnet)?;
-///
-/// assert_eq!(
-///     wallet.get_address(New).to_string(),
-///     "tb1pvjf9t34fznr53u5tqhejz4nr69luzkhlvsdsdfq9pglutrpve2xq7hps46"
-/// );
-/// # Ok::<_, Box<dyn std::error::Error>>(())
-/// ```
-pub struct P2TR<K: IntoDescriptorKey<Tap>>(pub K);
-
-impl<K: IntoDescriptorKey<Tap>> DescriptorTemplate for P2TR<K> {
-    fn build(self, _network: Network) -> Result<DescriptorTemplateOut, DescriptorError> {
-        descriptor!(tr(self.0))
-    }
-}
-
 /// BIP44 template. Expands to `pkh(key/44'/{0,1}'/0'/{0,1}/*)`
 ///
 /// Since there are hardened derivation steps, this template requires a private derivable key (generally a `xprv`/`tprv`).
@@ -195,7 +167,7 @@ impl<K: IntoDescriptorKey<Tap>> DescriptorTemplate for P2TR<K> {
 /// # use bdk::wallet::AddressIndex::New;
 /// use bdk::template::Bip44;
 ///
-/// let key = bitcoin::bip32::Xpriv::from_str("tprv8ZgxMBicQKsPeZRHk4rTG6orPS2CRNFX3njhUXx5vj9qGog5ZMH4uGReDWN5kCkY3jmWEtWause41CDvBRXD1shKknAMKxT99o9qUTRVC6m")?;
+/// let key = bitcoin::util::bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPeZRHk4rTG6orPS2CRNFX3njhUXx5vj9qGog5ZMH4uGReDWN5kCkY3jmWEtWause41CDvBRXD1shKknAMKxT99o9qUTRVC6m")?;
 /// let mut wallet = Wallet::new_no_persist(
 ///     Bip44(key.clone(), KeychainKind::External),
 ///     Some(Bip44(key, KeychainKind::Internal)),
@@ -232,8 +204,8 @@ impl<K: DerivableKey<Legacy>> DescriptorTemplate for Bip44<K> {
 /// # use bdk::wallet::AddressIndex::New;
 /// use bdk::template::Bip44Public;
 ///
-/// let key = bitcoin::bip32::Xpub::from_str("tpubDDDzQ31JkZB7VxUr9bjvBivDdqoFLrDPyLWtLapArAi51ftfmCb2DPxwLQzX65iNcXz1DGaVvyvo6JQ6rTU73r2gqdEo8uov9QKRb7nKCSU")?;
-/// let fingerprint = bitcoin::bip32::Fingerprint::from_str("c55b303f")?;
+/// let key = bitcoin::util::bip32::ExtendedPubKey::from_str("tpubDDDzQ31JkZB7VxUr9bjvBivDdqoFLrDPyLWtLapArAi51ftfmCb2DPxwLQzX65iNcXz1DGaVvyvo6JQ6rTU73r2gqdEo8uov9QKRb7nKCSU")?;
+/// let fingerprint = bitcoin::util::bip32::Fingerprint::from_str("c55b303f")?;
 /// let mut wallet = Wallet::new_no_persist(
 ///     Bip44Public(key.clone(), fingerprint, KeychainKind::External),
 ///     Some(Bip44Public(key, fingerprint, KeychainKind::Internal)),
@@ -270,7 +242,7 @@ impl<K: DerivableKey<Legacy>> DescriptorTemplate for Bip44Public<K> {
 /// # use bdk::wallet::AddressIndex::New;
 /// use bdk::template::Bip49;
 ///
-/// let key = bitcoin::bip32::Xpriv::from_str("tprv8ZgxMBicQKsPeZRHk4rTG6orPS2CRNFX3njhUXx5vj9qGog5ZMH4uGReDWN5kCkY3jmWEtWause41CDvBRXD1shKknAMKxT99o9qUTRVC6m")?;
+/// let key = bitcoin::util::bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPeZRHk4rTG6orPS2CRNFX3njhUXx5vj9qGog5ZMH4uGReDWN5kCkY3jmWEtWause41CDvBRXD1shKknAMKxT99o9qUTRVC6m")?;
 /// let mut wallet = Wallet::new_no_persist(
 ///     Bip49(key.clone(), KeychainKind::External),
 ///     Some(Bip49(key, KeychainKind::Internal)),
@@ -307,8 +279,8 @@ impl<K: DerivableKey<Segwitv0>> DescriptorTemplate for Bip49<K> {
 /// # use bdk::wallet::AddressIndex::New;
 /// use bdk::template::Bip49Public;
 ///
-/// let key = bitcoin::bip32::Xpub::from_str("tpubDC49r947KGK52X5rBWS4BLs5m9SRY3pYHnvRrm7HcybZ3BfdEsGFyzCMzayi1u58eT82ZeyFZwH7DD6Q83E3fM9CpfMtmnTygnLfP59jL9L")?;
-/// let fingerprint = bitcoin::bip32::Fingerprint::from_str("c55b303f")?;
+/// let key = bitcoin::util::bip32::ExtendedPubKey::from_str("tpubDC49r947KGK52X5rBWS4BLs5m9SRY3pYHnvRrm7HcybZ3BfdEsGFyzCMzayi1u58eT82ZeyFZwH7DD6Q83E3fM9CpfMtmnTygnLfP59jL9L")?;
+/// let fingerprint = bitcoin::util::bip32::Fingerprint::from_str("c55b303f")?;
 /// let mut wallet = Wallet::new_no_persist(
 ///     Bip49Public(key.clone(), fingerprint, KeychainKind::External),
 ///     Some(Bip49Public(key, fingerprint, KeychainKind::Internal)),
@@ -345,7 +317,7 @@ impl<K: DerivableKey<Segwitv0>> DescriptorTemplate for Bip49Public<K> {
 /// # use bdk::wallet::AddressIndex::New;
 /// use bdk::template::Bip84;
 ///
-/// let key = bitcoin::bip32::Xpriv::from_str("tprv8ZgxMBicQKsPeZRHk4rTG6orPS2CRNFX3njhUXx5vj9qGog5ZMH4uGReDWN5kCkY3jmWEtWause41CDvBRXD1shKknAMKxT99o9qUTRVC6m")?;
+/// let key = bitcoin::util::bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPeZRHk4rTG6orPS2CRNFX3njhUXx5vj9qGog5ZMH4uGReDWN5kCkY3jmWEtWause41CDvBRXD1shKknAMKxT99o9qUTRVC6m")?;
 /// let mut wallet = Wallet::new_no_persist(
 ///     Bip84(key.clone(), KeychainKind::External),
 ///     Some(Bip84(key, KeychainKind::Internal)),
@@ -382,8 +354,8 @@ impl<K: DerivableKey<Segwitv0>> DescriptorTemplate for Bip84<K> {
 /// # use bdk::wallet::AddressIndex::New;
 /// use bdk::template::Bip84Public;
 ///
-/// let key = bitcoin::bip32::Xpub::from_str("tpubDC2Qwo2TFsaNC4ju8nrUJ9mqVT3eSgdmy1yPqhgkjwmke3PRXutNGRYAUo6RCHTcVQaDR3ohNU9we59brGHuEKPvH1ags2nevW5opEE9Z5Q")?;
-/// let fingerprint = bitcoin::bip32::Fingerprint::from_str("c55b303f")?;
+/// let key = bitcoin::util::bip32::ExtendedPubKey::from_str("tpubDC2Qwo2TFsaNC4ju8nrUJ9mqVT3eSgdmy1yPqhgkjwmke3PRXutNGRYAUo6RCHTcVQaDR3ohNU9we59brGHuEKPvH1ags2nevW5opEE9Z5Q")?;
+/// let fingerprint = bitcoin::util::bip32::Fingerprint::from_str("c55b303f")?;
 /// let mut wallet = Wallet::new_no_persist(
 ///     Bip84Public(key.clone(), fingerprint, KeychainKind::External),
 ///     Some(Bip84Public(key, fingerprint, KeychainKind::Internal)),
@@ -405,81 +377,6 @@ impl<K: DerivableKey<Segwitv0>> DescriptorTemplate for Bip84Public<K> {
    }
 }

-/// BIP86 template. Expands to `tr(key/86'/{0,1}'/0'/{0,1}/*)`
-///
-/// Since there are hardened derivation steps, this template requires a private derivable key (generally a `xprv`/`tprv`).
-///
-/// See [`Bip86Public`] for a template that can work with a `xpub`/`tpub`.
-///
-/// ## Example
-///
-/// ```
-/// # use std::str::FromStr;
-/// # use bdk::bitcoin::{PrivateKey, Network};
-/// # use bdk::{Wallet,  KeychainKind};
-/// # use bdk::wallet::AddressIndex::New;
-/// use bdk::template::Bip86;
-///
-/// let key = bitcoin::bip32::Xpriv::from_str("tprv8ZgxMBicQKsPeZRHk4rTG6orPS2CRNFX3njhUXx5vj9qGog5ZMH4uGReDWN5kCkY3jmWEtWause41CDvBRXD1shKknAMKxT99o9qUTRVC6m")?;
-/// let mut wallet = Wallet::new_no_persist(
-///     Bip86(key.clone(), KeychainKind::External),
-///     Some(Bip86(key, KeychainKind::Internal)),
-///     Network::Testnet,
-/// )?;
-///
-/// assert_eq!(wallet.get_address(New).to_string(), "tb1p5unlj09djx8xsjwe97269kqtxqpwpu2epeskgqjfk4lnf69v4tnqpp35qu");
-/// assert_eq!(wallet.public_descriptor(KeychainKind::External).unwrap().to_string(), "tr([c55b303f/86'/1'/0']tpubDCiHofpEs47kx358bPdJmTZHmCDqQ8qw32upCSxHrSEdeeBs2T5Mq6QMB2ukeMqhNBiyhosBvJErteVhfURPGXPv3qLJPw5MVpHUewsbP2m/0/*)#dkgvr5hm");
-/// # Ok::<_, Box<dyn std::error::Error>>(())
-/// ```
-pub struct Bip86<K: DerivableKey<Tap>>(pub K, pub KeychainKind);
-
-impl<K: DerivableKey<Tap>> DescriptorTemplate for Bip86<K> {
-    fn build(self, network: Network) -> Result<DescriptorTemplateOut, DescriptorError> {
-        P2TR(segwit_v1::make_bipxx_private(86, self.0, self.1, network)?).build(network)
-    }
-}
-
-/// BIP86 public template. Expands to `tr(key/{0,1}/*)`
-///
-/// This assumes that the key used has already been derived with `m/86'/0'/0'` for Mainnet or `m/86'/1'/0'` for Testnet.
-///
-/// This template requires the parent fingerprint to populate correctly the metadata of PSBTs.
-///
-/// See [`Bip86`] for a template that does the full derivation, but requires private data
-/// for the key.
-///
-/// ## Example
-///
-/// ```
-/// # use std::str::FromStr;
-/// # use bdk::bitcoin::{PrivateKey, Network};
-/// # use bdk::{Wallet,  KeychainKind};
-/// # use bdk::wallet::AddressIndex::New;
-/// use bdk::template::Bip86Public;
-///
-/// let key = bitcoin::bip32::Xpub::from_str("tpubDC2Qwo2TFsaNC4ju8nrUJ9mqVT3eSgdmy1yPqhgkjwmke3PRXutNGRYAUo6RCHTcVQaDR3ohNU9we59brGHuEKPvH1ags2nevW5opEE9Z5Q")?;
-/// let fingerprint = bitcoin::bip32::Fingerprint::from_str("c55b303f")?;
-/// let mut wallet = Wallet::new_no_persist(
-///     Bip86Public(key.clone(), fingerprint, KeychainKind::External),
-///     Some(Bip86Public(key, fingerprint, KeychainKind::Internal)),
-///     Network::Testnet,
-/// )?;
-///
-/// assert_eq!(wallet.get_address(New).to_string(), "tb1pwjp9f2k5n0xq73ecuu0c5njvgqr3vkh7yaylmpqvsuuaafymh0msvcmh37");
-/// assert_eq!(wallet.public_descriptor(KeychainKind::External).unwrap().to_string(), "tr([c55b303f/86'/1'/0']tpubDC2Qwo2TFsaNC4ju8nrUJ9mqVT3eSgdmy1yPqhgkjwmke3PRXutNGRYAUo6RCHTcVQaDR3ohNU9we59brGHuEKPvH1ags2nevW5opEE9Z5Q/0/*)#2p65srku");
-/// # Ok::<_, Box<dyn std::error::Error>>(())
-/// ```
-pub struct Bip86Public<K: DerivableKey<Tap>>(pub K, pub bip32::Fingerprint, pub KeychainKind);
-
-impl<K: DerivableKey<Tap>> DescriptorTemplate for Bip86Public<K> {
-    fn build(self, network: Network) -> Result<DescriptorTemplateOut, DescriptorError> {
-        P2TR(segwit_v1::make_bipxx_public(
-            86, self.0, self.1, self.2, network,
-        )?)
-        .build(network)
-    }
-}
-
 macro_rules! expand_make_bipxx {
    ( $mod_name:ident, $ctx:ty ) => {
        mod $mod_name {
@@ -546,7 +443,6 @@ macro_rules! expand_make_bipxx {

 expand_make_bipxx!(legacy, Legacy);
 expand_make_bipxx!(segwit_v0, Segwitv0);
-expand_make_bipxx!(segwit_v1, Tap);

 #[cfg(test)]
 mod test {
@@ -559,37 +455,38 @@ mod test {
    use crate::descriptor::{DescriptorError, DescriptorMeta};
    use crate::keys::ValidNetworks;
    use assert_matches::assert_matches;
+    use bitcoin::network::constants::Network::Regtest;
    use miniscript::descriptor::{DescriptorPublicKey, KeyMap};
    use miniscript::Descriptor;

    // BIP44 `pkh(key/44'/{0,1}'/0'/{0,1}/*)`
    #[test]
    fn test_bip44_template_cointype() {
-        use bitcoin::bip32::ChildNumber::{self, Hardened};
+        use bitcoin::util::bip32::ChildNumber::{self, Hardened};

-        let xprvkey = bitcoin::bip32::Xpriv::from_str("xprv9s21ZrQH143K2fpbqApQL69a4oKdGVnVN52R82Ft7d1pSqgKmajF62acJo3aMszZb6qQ22QsVECSFxvf9uyxFUvFYQMq3QbtwtRSMjLAhMf").unwrap();
+        let xprvkey = bitcoin::util::bip32::ExtendedPrivKey::from_str("xprv9s21ZrQH143K2fpbqApQL69a4oKdGVnVN52R82Ft7d1pSqgKmajF62acJo3aMszZb6qQ22QsVECSFxvf9uyxFUvFYQMq3QbtwtRSMjLAhMf").unwrap();
        assert_eq!(Network::Bitcoin, xprvkey.network);
        let xdesc = Bip44(xprvkey, KeychainKind::Internal)
            .build(Network::Bitcoin)
            .unwrap();

        if let ExtendedDescriptor::Pkh(pkh) = xdesc.0 {
-            let path: Vec<ChildNumber> = pkh.into_inner().full_derivation_path().unwrap().into();
-            let purpose = path.first().unwrap();
+            let path: Vec<ChildNumber> = pkh.into_inner().full_derivation_path().into();
+            let purpose = path.get(0).unwrap();
            assert_matches!(purpose, Hardened { index: 44 });
            let coin_type = path.get(1).unwrap();
            assert_matches!(coin_type, Hardened { index: 0 });
        }

-        let tprvkey = bitcoin::bip32::Xpriv::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
+        let tprvkey = bitcoin::util::bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
        assert_eq!(Network::Testnet, tprvkey.network);
        let tdesc = Bip44(tprvkey, KeychainKind::Internal)
            .build(Network::Testnet)
            .unwrap();

        if let ExtendedDescriptor::Pkh(pkh) = tdesc.0 {
-            let path: Vec<ChildNumber> = pkh.into_inner().full_derivation_path().unwrap().into();
-            let purpose = path.first().unwrap();
+            let path: Vec<ChildNumber> = pkh.into_inner().full_derivation_path().into();
+            let purpose = path.get(0).unwrap();
            assert_matches!(purpose, Hardened { index: 44 });
            let coin_type = path.get(1).unwrap();
            assert_matches!(coin_type, Hardened { index: 1 });
@@ -600,23 +497,20 @@ mod test {
    fn check(
        desc: Result<(Descriptor<DescriptorPublicKey>, KeyMap, ValidNetworks), DescriptorError>,
        is_witness: bool,
-        is_taproot: bool,
        is_fixed: bool,
-        network: Network,
        expected: &[&str],
    ) {
        let (desc, _key_map, _networks) = desc.unwrap();
        assert_eq!(desc.is_witness(), is_witness);
-        assert_eq!(desc.is_taproot(), is_taproot);
        assert_eq!(!desc.has_wildcard(), is_fixed);
        for i in 0..expected.len() {
            let index = i as u32;
            let child_desc = if !desc.has_wildcard() {
-                desc.at_derivation_index(0).unwrap()
+                desc.at_derivation_index(0)
            } else {
-                desc.at_derivation_index(index).unwrap()
+                desc.at_derivation_index(index)
            };
-            let address = child_desc.address(network).unwrap();
+            let address = child_desc.address(Regtest).unwrap();
            assert_eq!(address.to_string(), *expected.get(i).unwrap());
        }
    }
@@ -630,9 +524,7 @@ mod test {
        check(
            P2Pkh(prvkey).build(Network::Bitcoin),
            false,
-            false,
            true,
-            Network::Regtest,
            &["mwJ8hxFYW19JLuc65RCTaP4v1rzVU8cVMT"],
        );

@@ -643,9 +535,7 @@ mod test {
        check(
            P2Pkh(pubkey).build(Network::Bitcoin),
            false,
-            false,
            true,
-            Network::Regtest,
            &["muZpTpBYhxmRFuCjLc7C6BBDF32C8XVJUi"],
        );
    }
@@ -659,9 +549,7 @@ mod test {
        check(
            P2Wpkh_P2Sh(prvkey).build(Network::Bitcoin),
            true,
-            false,
            true,
-            Network::Regtest,
            &["2NB4ox5VDRw1ecUv6SnT3VQHPXveYztRqk5"],
        );

@@ -672,9 +560,7 @@ mod test {
        check(
            P2Wpkh_P2Sh(pubkey).build(Network::Bitcoin),
            true,
-            false,
            true,
-            Network::Regtest,
            &["2N5LiC3CqzxDamRTPG1kiNv1FpNJQ7x28sb"],
        );
    }
@@ -688,9 +574,7 @@ mod test {
        check(
            P2Wpkh(prvkey).build(Network::Bitcoin),
            true,
-            false,
            true,
-            Network::Regtest,
            &["bcrt1q4525hmgw265tl3drrl8jjta7ayffu6jfcwxx9y"],
        );

@@ -701,52 +585,19 @@ mod test {
        check(
            P2Wpkh(pubkey).build(Network::Bitcoin),
            true,
-            false,
            true,
-            Network::Regtest,
            &["bcrt1qngw83fg8dz0k749cg7k3emc7v98wy0c7azaa6h"],
        );
    }

-    // P2TR `tr(key)`
-    #[test]
-    fn test_p2tr_template() {
-        let prvkey =
-            bitcoin::PrivateKey::from_wif("cTc4vURSzdx6QE6KVynWGomDbLaA75dNALMNyfjh3p8DRRar84Um")
-                .unwrap();
-        check(
-            P2TR(prvkey).build(Network::Bitcoin),
-            false,
-            true,
-            true,
-            Network::Regtest,
-            &["bcrt1pvjf9t34fznr53u5tqhejz4nr69luzkhlvsdsdfq9pglutrpve2xqnwtkqq"],
-        );
-
-        let pubkey = bitcoin::PublicKey::from_str(
-            "03a34b99f22c790c4e36b2b3c2c35a36db06226e41c692fc82b8b56ac1c540c5bd",
-        )
-        .unwrap();
-        check(
-            P2TR(pubkey).build(Network::Bitcoin),
-            false,
-            true,
-            true,
-            Network::Regtest,
-            &["bcrt1pw74tdcrxlzn5r8z6ku2vztr86fgq0m245s72mjktf4afwzsf8ugs4evwdf"],
-        );
-    }
-
    // BIP44 `pkh(key/44'/0'/0'/{0,1}/*)`
    #[test]
    fn test_bip44_template() {
-        let prvkey = bitcoin::bip32::Xpriv::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
+        let prvkey = bitcoin::util::bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
        check(
            Bip44(prvkey, KeychainKind::External).build(Network::Bitcoin),
            false,
            false,
-            false,
-            Network::Regtest,
            &[
                "n453VtnjDHPyDt2fDstKSu7A3YCJoHZ5g5",
                "mvfrrumXgTtwFPWDNUecBBgzuMXhYM7KRP",
@@ -757,8 +608,6 @@ mod test {
            Bip44(prvkey, KeychainKind::Internal).build(Network::Bitcoin),
            false,
            false,
-            false,
-            Network::Regtest,
            &[
                "muHF98X9KxEzdKrnFAX85KeHv96eXopaip",
                "n4hpyLJE5ub6B5Bymv4eqFxS5KjrewSmYR",
@@ -770,14 +619,12 @@ mod test {
    // BIP44 public `pkh(key/{0,1}/*)`
    #[test]
    fn test_bip44_public_template() {
-        let pubkey = bitcoin::bip32::Xpub::from_str("tpubDDDzQ31JkZB7VxUr9bjvBivDdqoFLrDPyLWtLapArAi51ftfmCb2DPxwLQzX65iNcXz1DGaVvyvo6JQ6rTU73r2gqdEo8uov9QKRb7nKCSU").unwrap();
-        let fingerprint = bitcoin::bip32::Fingerprint::from_str("c55b303f").unwrap();
+        let pubkey = bitcoin::util::bip32::ExtendedPubKey::from_str("tpubDDDzQ31JkZB7VxUr9bjvBivDdqoFLrDPyLWtLapArAi51ftfmCb2DPxwLQzX65iNcXz1DGaVvyvo6JQ6rTU73r2gqdEo8uov9QKRb7nKCSU").unwrap();
+        let fingerprint = bitcoin::util::bip32::Fingerprint::from_str("c55b303f").unwrap();
        check(
            Bip44Public(pubkey, fingerprint, KeychainKind::External).build(Network::Bitcoin),
            false,
            false,
-            false,
-            Network::Regtest,
            &[
                "miNG7dJTzJqNbFS19svRdTCisC65dsubtR",
                "n2UqaDbCjWSFJvpC84m3FjUk5UaeibCzYg",
@@ -788,8 +635,6 @@ mod test {
            Bip44Public(pubkey, fingerprint, KeychainKind::Internal).build(Network::Bitcoin),
            false,
            false,
-            false,
-            Network::Regtest,
            &[
                "moDr3vJ8wpt5nNxSK55MPq797nXJb2Ru9H",
                "ms7A1Yt4uTezT2XkefW12AvLoko8WfNJMG",
@@ -801,13 +646,11 @@ mod test {
    // BIP49 `sh(wpkh(key/49'/0'/0'/{0,1}/*))`
    #[test]
    fn test_bip49_template() {
-        let prvkey = bitcoin::bip32::Xpriv::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
+        let prvkey = bitcoin::util::bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
        check(
            Bip49(prvkey, KeychainKind::External).build(Network::Bitcoin),
            true,
            false,
-            false,
-            Network::Regtest,
            &[
                "2N9bCAJXGm168MjVwpkBdNt6ucka3PKVoUV",
                "2NDckYkqrYyDMtttEav5hB3Bfw9EGAW5HtS",
@@ -818,8 +661,6 @@ mod test {
            Bip49(prvkey, KeychainKind::Internal).build(Network::Bitcoin),
            true,
            false,
-            false,
-            Network::Regtest,
            &[
                "2NB3pA8PnzJLGV8YEKNDFpbViZv3Bm1K6CG",
                "2NBiX2Wzxngb5rPiWpUiJQ2uLVB4HBjFD4p",
@@ -831,14 +672,12 @@ mod test {
    // BIP49 public `sh(wpkh(key/{0,1}/*))`
    #[test]
    fn test_bip49_public_template() {
-        let pubkey = bitcoin::bip32::Xpub::from_str("tpubDC49r947KGK52X5rBWS4BLs5m9SRY3pYHnvRrm7HcybZ3BfdEsGFyzCMzayi1u58eT82ZeyFZwH7DD6Q83E3fM9CpfMtmnTygnLfP59jL9L").unwrap();
-        let fingerprint = bitcoin::bip32::Fingerprint::from_str("c55b303f").unwrap();
+        let pubkey = bitcoin::util::bip32::ExtendedPubKey::from_str("tpubDC49r947KGK52X5rBWS4BLs5m9SRY3pYHnvRrm7HcybZ3BfdEsGFyzCMzayi1u58eT82ZeyFZwH7DD6Q83E3fM9CpfMtmnTygnLfP59jL9L").unwrap();
+        let fingerprint = bitcoin::util::bip32::Fingerprint::from_str("c55b303f").unwrap();
        check(
            Bip49Public(pubkey, fingerprint, KeychainKind::External).build(Network::Bitcoin),
            true,
            false,
-            false,
-            Network::Regtest,
            &[
                "2N3K4xbVAHoiTQSwxkZjWDfKoNC27pLkYnt",
                "2NCTQfJ1sZa3wQ3pPseYRHbaNEpC3AquEfX",
@@ -849,8 +688,6 @@ mod test {
            Bip49Public(pubkey, fingerprint, KeychainKind::Internal).build(Network::Bitcoin),
            true,
            false,
-            false,
-            Network::Regtest,
            &[
                "2NF2vttKibwyxigxtx95Zw8K7JhDbo5zPVJ",
                "2Mtmyd8taksxNVWCJ4wVvaiss7QPZGcAJuH",
@@ -862,13 +699,11 @@ mod test {
    // BIP84 `wpkh(key/84'/0'/0'/{0,1}/*)`
    #[test]
    fn test_bip84_template() {
-        let prvkey = bitcoin::bip32::Xpriv::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
+        let prvkey = bitcoin::util::bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPcx5nBGsR63Pe8KnRUqmbJNENAfGftF3yuXoMMoVJJcYeUw5eVkm9WBPjWYt6HMWYJNesB5HaNVBaFc1M6dRjWSYnmewUMYy").unwrap();
        check(
            Bip84(prvkey, KeychainKind::External).build(Network::Bitcoin),
            true,
            false,
-            false,
-            Network::Regtest,
            &[
                "bcrt1qkmvk2nadgplmd57ztld8nf8v2yxkzmdvwtjf8s",
                "bcrt1qx0v6zgfwe50m4kqc58cqzcyem7ay2sfl3gvqhp",
@@ -879,8 +714,6 @@ mod test {
            Bip84(prvkey, KeychainKind::Internal).build(Network::Bitcoin),
            true,
            false,
-            false,
-            Network::Regtest,
            &[
                "bcrt1qtrwtz00wxl69e5xex7amy4xzlxkaefg3gfdkxa",
                "bcrt1qqqasfhxpkkf7zrxqnkr2sfhn74dgsrc3e3ky45",
@@ -892,14 +725,12 @@ mod test {
    // BIP84 public `wpkh(key/{0,1}/*)`
    #[test]
    fn test_bip84_public_template() {
-        let pubkey = bitcoin::bip32::Xpub::from_str("tpubDC2Qwo2TFsaNC4ju8nrUJ9mqVT3eSgdmy1yPqhgkjwmke3PRXutNGRYAUo6RCHTcVQaDR3ohNU9we59brGHuEKPvH1ags2nevW5opEE9Z5Q").unwrap();
-        let fingerprint = bitcoin::bip32::Fingerprint::from_str("c55b303f").unwrap();
+        let pubkey = bitcoin::util::bip32::ExtendedPubKey::from_str("tpubDC2Qwo2TFsaNC4ju8nrUJ9mqVT3eSgdmy1yPqhgkjwmke3PRXutNGRYAUo6RCHTcVQaDR3ohNU9we59brGHuEKPvH1ags2nevW5opEE9Z5Q").unwrap();
+        let fingerprint = bitcoin::util::bip32::Fingerprint::from_str("c55b303f").unwrap();
        check(
            Bip84Public(pubkey, fingerprint, KeychainKind::External).build(Network::Bitcoin),
            true,
            false,
-            false,
-            Network::Regtest,
            &[
                "bcrt1qedg9fdlf8cnnqfd5mks6uz5w4kgpk2prcdvd0h",
                "bcrt1q3lncdlwq3lgcaaeyruynjnlccr0ve0kakh6ana",
@@ -910,8 +741,6 @@ mod test {
            Bip84Public(pubkey, fingerprint, KeychainKind::Internal).build(Network::Bitcoin),
            true,
            false,
-            false,
-            Network::Regtest,
            &[
                "bcrt1qm6wqukenh7guu792lj2njgw9n78cmwsy8xy3z2",
                "bcrt1q694twxtjn4nnrvnyvra769j0a23rllj5c6cgwp",
@@ -919,67 +748,4 @@ mod test {
            ],
        );
    }
-
-    // BIP86 `tr(key/86'/0'/0'/{0,1}/*)`
-    // Used addresses in test vector in https://github.com/bitcoin/bips/blob/master/bip-0086.mediawiki
-    #[test]
-    fn test_bip86_template() {
-        let prvkey = bitcoin::bip32::Xpriv::from_str("xprv9s21ZrQH143K3GJpoapnV8SFfukcVBSfeCficPSGfubmSFDxo1kuHnLisriDvSnRRuL2Qrg5ggqHKNVpxR86QEC8w35uxmGoggxtQTPvfUu").unwrap();
-        check(
-            Bip86(prvkey, KeychainKind::External).build(Network::Bitcoin),
-            false,
-            true,
-            false,
-            Network::Bitcoin,
-            &[
-                "bc1p5cyxnuxmeuwuvkwfem96lqzszd02n6xdcjrs20cac6yqjjwudpxqkedrcr",
-                "bc1p4qhjn9zdvkux4e44uhx8tc55attvtyu358kutcqkudyccelu0was9fqzwh",
-                "bc1p0d0rhyynq0awa9m8cqrcr8f5nxqx3aw29w4ru5u9my3h0sfygnzs9khxz8",
-            ],
-        );
-        check(
-            Bip86(prvkey, KeychainKind::Internal).build(Network::Bitcoin),
-            false,
-            true,
-            false,
-            Network::Bitcoin,
-            &[
-                "bc1p3qkhfews2uk44qtvauqyr2ttdsw7svhkl9nkm9s9c3x4ax5h60wqwruhk7",
-                "bc1ptdg60grjk9t3qqcqczp4tlyy3z47yrx9nhlrjsmw36q5a72lhdrs9f00nj",
-                "bc1pgcwgsu8naxp7xlp5p7ufzs7emtfza2las7r2e7krzjhe5qj5xz2q88kmk5",
-            ],
-        );
-    }
-
-    // BIP86 public `tr(key/{0,1}/*)`
-    // Used addresses in test vector in https://github.com/bitcoin/bips/blob/master/bip-0086.mediawiki
-    #[test]
-    fn test_bip86_public_template() {
-        let pubkey = bitcoin::bip32::Xpub::from_str("xpub6BgBgsespWvERF3LHQu6CnqdvfEvtMcQjYrcRzx53QJjSxarj2afYWcLteoGVky7D3UKDP9QyrLprQ3VCECoY49yfdDEHGCtMMj92pReUsQ").unwrap();
-        let fingerprint = bitcoin::bip32::Fingerprint::from_str("73c5da0a").unwrap();
-        check(
-            Bip86Public(pubkey, fingerprint, KeychainKind::External).build(Network::Bitcoin),
-            false,
-            true,
-            false,
-            Network::Bitcoin,
-            &[
-                "bc1p5cyxnuxmeuwuvkwfem96lqzszd02n6xdcjrs20cac6yqjjwudpxqkedrcr",
-                "bc1p4qhjn9zdvkux4e44uhx8tc55attvtyu358kutcqkudyccelu0was9fqzwh",
-                "bc1p0d0rhyynq0awa9m8cqrcr8f5nxqx3aw29w4ru5u9my3h0sfygnzs9khxz8",
-            ],
-        );
-        check(
-            Bip86Public(pubkey, fingerprint, KeychainKind::Internal).build(Network::Bitcoin),
-            false,
-            true,
-            false,
-            Network::Bitcoin,
-            &[
-                "bc1p3qkhfews2uk44qtvauqyr2ttdsw7svhkl9nkm9s9c3x4ax5h60wqwruhk7",
-                "bc1ptdg60grjk9t3qqcqczp4tlyy3z47yrx9nhlrjsmw36q5a72lhdrs9f00nj",
-                "bc1pgcwgsu8naxp7xlp5p7ufzs7emtfza2las7r2e7krzjhe5qj5xz2q88kmk5",
-            ],
-        );
-    }
 }
--- a/crates/bdk/src/error.rs
+++ b/crates/bdk/src/error.rs
@@ -0,0 +1,199 @@
+// Bitcoin Dev Kit
+// Written in 2020 by Alekos Filini <alekos.filini@gmail.com>
+//
+// Copyright (c) 2020-2021 Bitcoin Dev Kit Developers
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
+use crate::bitcoin::Network;
+use crate::{descriptor, wallet};
+use alloc::{string::String, vec::Vec};
+use bitcoin::{OutPoint, Txid};
+use core::fmt;
+
+/// Errors that can be thrown by the [`Wallet`](crate::wallet::Wallet)
+#[derive(Debug)]
+pub enum Error {
+    /// Generic error
+    Generic(String),
+    /// Cannot build a tx without recipients
+    NoRecipients,
+    /// `manually_selected_only` option is selected but no utxo has been passed
+    NoUtxosSelected,
+    /// Output created is under the dust limit, 546 satoshis
+    OutputBelowDustLimit(usize),
+    /// Wallet's UTXO set is not enough to cover recipient's requested plus fee
+    InsufficientFunds {
+        /// Sats needed for some transaction
+        needed: u64,
+        /// Sats available for spending
+        available: u64,
+    },
+    /// Branch and bound coin selection possible attempts with sufficiently big UTXO set could grow
+    /// exponentially, thus a limit is set, and when hit, this error is thrown
+    BnBTotalTriesExceeded,
+    /// Branch and bound coin selection tries to avoid needing a change by finding the right inputs for
+    /// the desired outputs plus fee, if there is not such combination this error is thrown
+    BnBNoExactMatch,
+    /// Happens when trying to spend an UTXO that is not in the internal database
+    UnknownUtxo,
+    /// Thrown when a tx is not found in the internal database
+    TransactionNotFound,
+    /// Happens when trying to bump a transaction that is already confirmed
+    TransactionConfirmed,
+    /// Trying to replace a tx that has a sequence >= `0xFFFFFFFE`
+    IrreplaceableTransaction,
+    /// When bumping a tx the fee rate requested is lower than required
+    FeeRateTooLow {
+        /// Required fee rate (satoshi/vbyte)
+        required: crate::types::FeeRate,
+    },
+    /// When bumping a tx the absolute fee requested is lower than replaced tx absolute fee
+    FeeTooLow {
+        /// Required fee absolute value (satoshi)
+        required: u64,
+    },
+    /// Node doesn't have data to estimate a fee rate
+    FeeRateUnavailable,
+    /// In order to use the [`TxBuilder::add_global_xpubs`] option every extended
+    /// key in the descriptor must either be a master key itself (having depth = 0) or have an
+    /// explicit origin provided
+    ///
+    /// [`TxBuilder::add_global_xpubs`]: crate::wallet::tx_builder::TxBuilder::add_global_xpubs
+    MissingKeyOrigin(String),
+    /// Error while working with [`keys`](crate::keys)
+    Key(crate::keys::KeyError),
+    /// Descriptor checksum mismatch
+    ChecksumMismatch,
+    /// Spending policy is not compatible with this [`KeychainKind`](crate::types::KeychainKind)
+    SpendingPolicyRequired(crate::types::KeychainKind),
+    /// Error while extracting and manipulating policies
+    InvalidPolicyPathError(crate::descriptor::policy::PolicyError),
+    /// Signing error
+    Signer(crate::wallet::signer::SignerError),
+    /// Requested outpoint doesn't exist in the tx (vout greater than available outputs)
+    InvalidOutpoint(OutPoint),
+    /// Error related to the parsing and usage of descriptors
+    Descriptor(crate::descriptor::error::Error),
+    /// Miniscript error
+    Miniscript(miniscript::Error),
+    /// Miniscript PSBT error
+    MiniscriptPsbt(MiniscriptPsbtError),
+    /// BIP32 error
+    Bip32(bitcoin::util::bip32::Error),
+    /// Partially signed bitcoin transaction error
+    Psbt(bitcoin::util::psbt::Error),
+}
+
+/// Errors returned by miniscript when updating inconsistent PSBTs
+#[derive(Debug, Clone)]
+pub enum MiniscriptPsbtError {
+    Conversion(miniscript::descriptor::ConversionError),
+    UtxoUpdate(miniscript::psbt::UtxoUpdateError),
+    OutputUpdate(miniscript::psbt::OutputUpdateError),
+}
+
+impl fmt::Display for MiniscriptPsbtError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Conversion(err) => write!(f, "Conversion error: {}", err),
+            Self::UtxoUpdate(err) => write!(f, "UTXO update error: {}", err),
+            Self::OutputUpdate(err) => write!(f, "Output update error: {}", err),
+        }
+    }
+}
+
+impl std::error::Error for MiniscriptPsbtError {}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Generic(err) => write!(f, "Generic error: {}", err),
+            Self::NoRecipients => write!(f, "Cannot build tx without recipients"),
+            Self::NoUtxosSelected => write!(f, "No UTXO selected"),
+            Self::OutputBelowDustLimit(limit) => {
+                write!(f, "Output below the dust limit: {}", limit)
+            }
+            Self::InsufficientFunds { needed, available } => write!(
+                f,
+                "Insufficient funds: {} sat available of {} sat needed",
+                available, needed
+            ),
+            Self::BnBTotalTriesExceeded => {
+                write!(f, "Branch and bound coin selection: total tries exceeded")
+            }
+            Self::BnBNoExactMatch => write!(f, "Branch and bound coin selection: not exact match"),
+            Self::UnknownUtxo => write!(f, "UTXO not found in the internal database"),
+            Self::TransactionNotFound => {
+                write!(f, "Transaction not found in the internal database")
+            }
+            Self::TransactionConfirmed => write!(f, "Transaction already confirmed"),
+            Self::IrreplaceableTransaction => write!(f, "Transaction can't be replaced"),
+            Self::FeeRateTooLow { required } => write!(
+                f,
+                "Fee rate too low: required {} sat/vbyte",
+                required.as_sat_per_vb()
+            ),
+            Self::FeeTooLow { required } => write!(f, "Fee to low: required {} sat", required),
+            Self::FeeRateUnavailable => write!(f, "Fee rate unavailable"),
+            Self::MissingKeyOrigin(err) => write!(f, "Missing key origin: {}", err),
+            Self::Key(err) => write!(f, "Key error: {}", err),
+            Self::ChecksumMismatch => write!(f, "Descriptor checksum mismatch"),
+            Self::SpendingPolicyRequired(keychain_kind) => {
+                write!(f, "Spending policy required: {:?}", keychain_kind)
+            }
+            Self::InvalidPolicyPathError(err) => write!(f, "Invalid policy path: {}", err),
+            Self::Signer(err) => write!(f, "Signer error: {}", err),
+            Self::InvalidOutpoint(outpoint) => write!(
+                f,
+                "Requested outpoint doesn't exist in the tx: {}",
+                outpoint
+            ),
+            Self::Descriptor(err) => write!(f, "Descriptor error: {}", err),
+            Self::Miniscript(err) => write!(f, "Miniscript error: {}", err),
+            Self::MiniscriptPsbt(err) => write!(f, "Miniscript PSBT error: {}", err),
+            Self::Bip32(err) => write!(f, "BIP32 error: {}", err),
+            Self::Psbt(err) => write!(f, "PSBT error: {}", err),
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for Error {}
+
+macro_rules! impl_error {
+    ( $from:ty, $to:ident ) => {
+        impl_error!($from, $to, Error);
+    };
+    ( $from:ty, $to:ident, $impl_for:ty ) => {
+        impl core::convert::From<$from> for $impl_for {
+            fn from(err: $from) -> Self {
+                <$impl_for>::$to(err)
+            }
+        }
+    };
+}
+
+impl_error!(descriptor::error::Error, Descriptor);
+impl_error!(descriptor::policy::PolicyError, InvalidPolicyPathError);
+impl_error!(wallet::signer::SignerError, Signer);
+
+impl From<crate::keys::KeyError> for Error {
+    fn from(key_error: crate::keys::KeyError) -> Error {
+        match key_error {
+            crate::keys::KeyError::Miniscript(inner) => Error::Miniscript(inner),
+            crate::keys::KeyError::Bip32(inner) => Error::Bip32(inner),
+            crate::keys::KeyError::InvalidChecksum => Error::ChecksumMismatch,
+            e => Error::Key(e),
+        }
+    }
+}
+
+impl_error!(miniscript::Error, Miniscript);
+impl_error!(MiniscriptPsbtError, MiniscriptPsbt);
+impl_error!(bitcoin::util::bip32::Error, Bip32);
+impl_error!(bitcoin::util::psbt::Error, Psbt);
--- a/crates/bdk/src/keys/bip39.rs
+++ b/crates/bdk/src/keys/bip39.rs
@@ -15,7 +15,7 @@
 // something that should be fairly simple to re-implement.

 use alloc::string::String;
-use bitcoin::bip32;
+use bitcoin::util::bip32;
 use bitcoin::Network;

 use miniscript::ScriptContext;
@@ -57,7 +57,7 @@ pub type MnemonicWithPassphrase = (Mnemonic, Option<String>);
 #[cfg_attr(docsrs, doc(cfg(feature = "keys-bip39")))]
 impl<Ctx: ScriptContext> DerivableKey<Ctx> for Seed {
    fn into_extended_key(self) -> Result<ExtendedKey<Ctx>, KeyError> {
-        Ok(bip32::Xpriv::new_master(Network::Bitcoin, &self[..])?.into())
+        Ok(bip32::ExtendedPrivKey::new_master(Network::Bitcoin, &self[..])?.into())
    }

    fn into_descriptor_key(
@@ -142,7 +142,7 @@ impl<Ctx: ScriptContext> GeneratableKey<Ctx> for Mnemonic {
        (word_count, language): Self::Options,
        entropy: Self::Entropy,
    ) -> Result<GeneratedKey<Self, Ctx>, Self::Error> {
-        let entropy = &entropy[..(word_count as usize / 8)];
+        let entropy = &entropy.as_ref()[..(word_count as usize / 8)];
        let mnemonic = Mnemonic::from_entropy_in(language, entropy)?;

        Ok(GeneratedKey::new(mnemonic, any_network()))
@@ -154,7 +154,7 @@ mod test {
    use alloc::string::ToString;
    use core::str::FromStr;

-    use bitcoin::bip32;
+    use bitcoin::util::bip32;

    use bip39::{Language, Mnemonic};

--- a/crates/bdk/src/keys/mod.rs
+++ b/crates/bdk/src/keys/mod.rs
@@ -15,15 +15,14 @@ use crate::collections::HashSet;
 use alloc::string::{String, ToString};
 use alloc::vec::Vec;
 use core::any::TypeId;
-use core::fmt;
 use core::marker::PhantomData;
 use core::ops::Deref;
 use core::str::FromStr;

 use bitcoin::secp256k1::{self, Secp256k1, Signing};

-use bitcoin::bip32;
-use bitcoin::{key::XOnlyPublicKey, Network, PrivateKey, PublicKey};
+use bitcoin::util::bip32;
+use bitcoin::{Network, PrivateKey, PublicKey, XOnlyPublicKey};

 use miniscript::descriptor::{Descriptor, DescriptorXKey, Wildcard};
 pub use miniscript::descriptor::{
@@ -110,7 +109,7 @@ impl<Ctx: ScriptContext> DescriptorKey<Ctx> {
                Ok((public, KeyMap::default(), valid_networks))
            }
            DescriptorKey::Secret(secret, valid_networks, _) => {
-                let mut key_map = KeyMap::new();
+                let mut key_map = KeyMap::with_capacity(1);

                let public = secret
                    .to_public(secp)
@@ -309,15 +308,15 @@ pub trait IntoDescriptorKey<Ctx: ScriptContext>: Sized {

 /// Enum for extended keys that can be either `xprv` or `xpub`
 ///
-/// An instance of [`ExtendedKey`] can be constructed from an [`Xpriv`](bip32::Xpriv)
-/// or an [`Xpub`](bip32::Xpub) by using the `From` trait.
+/// An instance of [`ExtendedKey`] can be constructed from an [`ExtendedPrivKey`](bip32::ExtendedPrivKey)
+/// or an [`ExtendedPubKey`](bip32::ExtendedPubKey) by using the `From` trait.
 ///
 /// Defaults to the [`Legacy`](miniscript::Legacy) context.
 pub enum ExtendedKey<Ctx: ScriptContext = miniscript::Legacy> {
    /// A private extended key, aka an `xprv`
-    Private((bip32::Xpriv, PhantomData<Ctx>)),
+    Private((bip32::ExtendedPrivKey, PhantomData<Ctx>)),
    /// A public extended key, aka an `xpub`
-    Public((bip32::Xpub, PhantomData<Ctx>)),
+    Public((bip32::ExtendedPubKey, PhantomData<Ctx>)),
 }

 impl<Ctx: ScriptContext> ExtendedKey<Ctx> {
@@ -329,9 +328,9 @@ impl<Ctx: ScriptContext> ExtendedKey<Ctx> {
        }
    }

-    /// Transform the [`ExtendedKey`] into an [`Xpriv`](bip32::Xpriv) for the
+    /// Transform the [`ExtendedKey`] into an [`ExtendedPrivKey`](bip32::ExtendedPrivKey) for the
    /// given [`Network`], if the key contains the private data
-    pub fn into_xprv(self, network: Network) -> Option<bip32::Xpriv> {
+    pub fn into_xprv(self, network: Network) -> Option<bip32::ExtendedPrivKey> {
        match self {
            ExtendedKey::Private((mut xprv, _)) => {
                xprv.network = network;
@@ -341,15 +340,15 @@ impl<Ctx: ScriptContext> ExtendedKey<Ctx> {
        }
    }

-    /// Transform the [`ExtendedKey`] into an [`Xpub`](bip32::Xpub) for the
+    /// Transform the [`ExtendedKey`] into an [`ExtendedPubKey`](bip32::ExtendedPubKey) for the
    /// given [`Network`]
    pub fn into_xpub<C: Signing>(
        self,
        network: bitcoin::Network,
        secp: &Secp256k1<C>,
-    ) -> bip32::Xpub {
+    ) -> bip32::ExtendedPubKey {
        let mut xpub = match self {
-            ExtendedKey::Private((xprv, _)) => bip32::Xpub::from_priv(secp, &xprv),
+            ExtendedKey::Private((xprv, _)) => bip32::ExtendedPubKey::from_priv(secp, &xprv),
            ExtendedKey::Public((xpub, _)) => xpub,
        };

@@ -358,14 +357,14 @@ impl<Ctx: ScriptContext> ExtendedKey<Ctx> {
    }
 }

-impl<Ctx: ScriptContext> From<bip32::Xpub> for ExtendedKey<Ctx> {
-    fn from(xpub: bip32::Xpub) -> Self {
+impl<Ctx: ScriptContext> From<bip32::ExtendedPubKey> for ExtendedKey<Ctx> {
+    fn from(xpub: bip32::ExtendedPubKey) -> Self {
        ExtendedKey::Public((xpub, PhantomData))
    }
 }

-impl<Ctx: ScriptContext> From<bip32::Xpriv> for ExtendedKey<Ctx> {
-    fn from(xprv: bip32::Xpriv) -> Self {
+impl<Ctx: ScriptContext> From<bip32::ExtendedPrivKey> for ExtendedKey<Ctx> {
+    fn from(xprv: bip32::ExtendedPrivKey) -> Self {
        ExtendedKey::Private((xprv, PhantomData))
    }
 }
@@ -383,28 +382,28 @@ impl<Ctx: ScriptContext> From<bip32::Xpriv> for ExtendedKey<Ctx> {
 ///
 /// ## Examples
 ///
-/// Key types that can be directly converted into an [`Xpriv`] or
-/// an [`Xpub`] can implement only the required `into_extended_key()` method.
+/// Key types that can be directly converted into an [`ExtendedPrivKey`] or
+/// an [`ExtendedPubKey`] can implement only the required `into_extended_key()` method.
 ///
 /// ```
 /// use bdk::bitcoin;
-/// use bdk::bitcoin::bip32;
+/// use bdk::bitcoin::util::bip32;
 /// use bdk::keys::{DerivableKey, ExtendedKey, KeyError, ScriptContext};
 ///
 /// struct MyCustomKeyType {
 ///     key_data: bitcoin::PrivateKey,
-///     chain_code: [u8; 32],
+///     chain_code: Vec<u8>,
 ///     network: bitcoin::Network,
 /// }
 ///
 /// impl<Ctx: ScriptContext> DerivableKey<Ctx> for MyCustomKeyType {
 ///     fn into_extended_key(self) -> Result<ExtendedKey<Ctx>, KeyError> {
-///         let xprv = bip32::Xpriv {
+///         let xprv = bip32::ExtendedPrivKey {
 ///             network: self.network,
 ///             depth: 0,
 ///             parent_fingerprint: bip32::Fingerprint::default(),
 ///             private_key: self.key_data.inner,
-///             chain_code: bip32::ChainCode::from(&self.chain_code),
+///             chain_code: bip32::ChainCode::from(self.chain_code.as_ref()),
 ///             child_number: bip32::ChildNumber::Normal { index: 0 },
 ///         };
 ///
@@ -413,30 +412,30 @@ impl<Ctx: ScriptContext> From<bip32::Xpriv> for ExtendedKey<Ctx> {
 /// }
 /// ```
 ///
-/// Types that don't internally encode the [`Network`] in which they are valid need some extra
+/// Types that don't internally encode the [`Network`](bitcoin::Network) in which they are valid need some extra
 /// steps to override the set of valid networks, otherwise only the network specified in the
-/// [`Xpriv`] or [`Xpub`] will be considered valid.
+/// [`ExtendedPrivKey`] or [`ExtendedPubKey`] will be considered valid.
 ///
 /// ```
 /// use bdk::bitcoin;
-/// use bdk::bitcoin::bip32;
+/// use bdk::bitcoin::util::bip32;
 /// use bdk::keys::{
 ///     any_network, DerivableKey, DescriptorKey, ExtendedKey, KeyError, ScriptContext,
 /// };
 ///
 /// struct MyCustomKeyType {
 ///     key_data: bitcoin::PrivateKey,
-///     chain_code: [u8; 32],
+///     chain_code: Vec<u8>,
 /// }
 ///
 /// impl<Ctx: ScriptContext> DerivableKey<Ctx> for MyCustomKeyType {
 ///     fn into_extended_key(self) -> Result<ExtendedKey<Ctx>, KeyError> {
-///         let xprv = bip32::Xpriv {
+///         let xprv = bip32::ExtendedPrivKey {
 ///             network: bitcoin::Network::Bitcoin, // pick an arbitrary network here
 ///             depth: 0,
 ///             parent_fingerprint: bip32::Fingerprint::default(),
 ///             private_key: self.key_data.inner,
-///             chain_code: bip32::ChainCode::from(&self.chain_code),
+///             chain_code: bip32::ChainCode::from(self.chain_code.as_ref()),
 ///             child_number: bip32::ChildNumber::Normal { index: 0 },
 ///         };
 ///
@@ -459,8 +458,8 @@ impl<Ctx: ScriptContext> From<bip32::Xpriv> for ExtendedKey<Ctx> {
 /// ```
 ///
 /// [`DerivationPath`]: (bip32::DerivationPath)
-/// [`Xpriv`]: (bip32::Xpriv)
-/// [`Xpub`]: (bip32::Xpub)
+/// [`ExtendedPrivKey`]: (bip32::ExtendedPrivKey)
+/// [`ExtendedPubKey`]: (bip32::ExtendedPubKey)
 pub trait DerivableKey<Ctx: ScriptContext = miniscript::Legacy>: Sized {
    /// Consume `self` and turn it into an [`ExtendedKey`]
    #[cfg_attr(
@@ -520,13 +519,13 @@ impl<Ctx: ScriptContext> DerivableKey<Ctx> for ExtendedKey<Ctx> {
    }
 }

-impl<Ctx: ScriptContext> DerivableKey<Ctx> for bip32::Xpub {
+impl<Ctx: ScriptContext> DerivableKey<Ctx> for bip32::ExtendedPubKey {
    fn into_extended_key(self) -> Result<ExtendedKey<Ctx>, KeyError> {
        Ok(self.into())
    }
 }

-impl<Ctx: ScriptContext> DerivableKey<Ctx> for bip32::Xpriv {
+impl<Ctx: ScriptContext> DerivableKey<Ctx> for bip32::ExtendedPrivKey {
    fn into_extended_key(self) -> Result<ExtendedKey<Ctx>, KeyError> {
        Ok(self.into())
    }
@@ -670,7 +669,7 @@ where
 {
 }

-impl<Ctx: ScriptContext> GeneratableKey<Ctx> for bip32::Xpriv {
+impl<Ctx: ScriptContext> GeneratableKey<Ctx> for bip32::ExtendedPrivKey {
    type Entropy = [u8; 32];

    type Options = ();
@@ -681,7 +680,7 @@ impl<Ctx: ScriptContext> GeneratableKey<Ctx> for bip32::Xpriv {
        entropy: Self::Entropy,
    ) -> Result<GeneratedKey<Self, Ctx>, Self::Error> {
        // pick a arbitrary network here, but say that we support all of them
-        let xprv = bip32::Xpriv::new_master(Network::Bitcoin, entropy.as_ref())?;
+        let xprv = bip32::ExtendedPrivKey::new_master(Network::Bitcoin, entropy.as_ref())?;
        Ok(GeneratedKey::new(xprv, any_network()))
    }
 }
@@ -754,7 +753,7 @@ fn expand_multi_keys<Pk: IntoDescriptorKey<Ctx>, Ctx: ScriptContext>(
    let (key_map, valid_networks) = key_maps_networks.into_iter().fold(
        (KeyMap::default(), any_network()),
        |(mut keys_acc, net_acc), (key, net)| {
-            keys_acc.extend(key);
+            keys_acc.extend(key.into_iter());
            let net_acc = merge_networks(&net_acc, &net);

            (keys_acc, net_acc)
@@ -927,25 +926,16 @@ pub enum KeyError {
    Message(String),

    /// BIP32 error
-    Bip32(bitcoin::bip32::Error),
+    Bip32(bitcoin::util::bip32::Error),
    /// Miniscript error
    Miniscript(miniscript::Error),
 }

-impl From<miniscript::Error> for KeyError {
-    fn from(err: miniscript::Error) -> Self {
-        KeyError::Miniscript(err)
-    }
-}
+impl_error!(miniscript::Error, Miniscript, KeyError);
+impl_error!(bitcoin::util::bip32::Error, Bip32, KeyError);

-impl From<bip32::Error> for KeyError {
-    fn from(err: bip32::Error) -> Self {
-        KeyError::Bip32(err)
-    }
-}
-
-impl fmt::Display for KeyError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+impl std::fmt::Display for KeyError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::InvalidScriptContext => write!(f, "Invalid script context"),
            Self::InvalidNetwork => write!(f, "Invalid network"),
@@ -962,7 +952,7 @@ impl std::error::Error for KeyError {}

 #[cfg(test)]
 pub mod test {
-    use bitcoin::bip32;
+    use bitcoin::util::bip32;

    use super::*;

@@ -971,7 +961,7 @@ pub mod test {
    #[test]
    fn test_keys_generate_xprv() {
        let generated_xprv: GeneratedKey<_, miniscript::Segwitv0> =
-            bip32::Xpriv::generate_with_entropy_default(TEST_ENTROPY).unwrap();
+            bip32::ExtendedPrivKey::generate_with_entropy_default(TEST_ENTROPY).unwrap();

        assert_eq!(generated_xprv.valid_networks, any_network());
        assert_eq!(generated_xprv.to_string(), "xprv9s21ZrQH143K4Xr1cJyqTvuL2FWR8eicgY9boWqMBv8MDVUZ65AXHnzBrK1nyomu6wdcabRgmGTaAKawvhAno1V5FowGpTLVx3jxzE5uk3Q");
--- a/crates/bdk/src/lib.rs
+++ b/crates/bdk/src/lib.rs
@@ -1,13 +1,5 @@
 #![doc = include_str!("../README.md")]
-// only enables the `doc_cfg` feature when the `docsrs` configuration attribute is defined
-#![cfg_attr(docsrs, feature(doc_cfg))]
-#![cfg_attr(
-    docsrs,
-    doc(html_logo_url = "https://github.com/bitcoindevkit/bdk/raw/master/static/bdk.png")
-)]
 #![no_std]
-#![warn(missing_docs)]
-
 #[cfg(feature = "std")]
 #[macro_use]
 extern crate std;
@@ -17,6 +9,9 @@ extern crate std;
 pub extern crate alloc;

 pub extern crate bitcoin;
+#[cfg(feature = "hardware-signer")]
+pub extern crate hwi;
+extern crate log;
 pub extern crate miniscript;
 extern crate serde;
 extern crate serde_json;
@@ -24,6 +19,9 @@ extern crate serde_json;
 #[cfg(feature = "keys-bip39")]
 extern crate bip39;

+#[allow(unused_imports)]
+#[macro_use]
+pub(crate) mod error;
 pub mod descriptor;
 pub mod keys;
 pub mod psbt;
@@ -32,6 +30,7 @@ pub mod wallet;

 pub use descriptor::template;
 pub use descriptor::HdKeyPaths;
+pub use error::Error;
 pub use types::*;
 pub use wallet::signer;
 pub use wallet::signer::SignOptions;
--- a/crates/bdk/src/psbt/mod.rs
+++ b/crates/bdk/src/psbt/mod.rs
@@ -9,12 +9,11 @@
 // You may not use this file except in accordance with one or both of these
 // licenses.

-//! Additional functions on the `rust-bitcoin` `Psbt` structure.
+//! Additional functions on the `rust-bitcoin` `PartiallySignedTransaction` structure.

+use crate::FeeRate;
 use alloc::vec::Vec;
-use bitcoin::Amount;
-use bitcoin::FeeRate;
-use bitcoin::Psbt;
+use bitcoin::util::psbt::PartiallySignedTransaction as Psbt;
 use bitcoin::TxOut;

 // TODO upstream the functions here to `rust-bitcoin`?
@@ -29,23 +28,31 @@ pub trait PsbtUtils {
    fn fee_amount(&self) -> Option<u64>;

    /// The transaction's fee rate. This value will only be accurate if calculated AFTER the
-    /// `Psbt` is finalized and all witness/signature data is added to the
+    /// `PartiallySignedTransaction` is finalized and all witness/signature data is added to the
    /// transaction.
    /// If the PSBT is missing a TxOut for an input returns None.
    fn fee_rate(&self) -> Option<FeeRate>;
 }

 impl PsbtUtils for Psbt {
+    #[allow(clippy::all)] // We want to allow `manual_map` but it is too new.
    fn get_utxo_for(&self, input_index: usize) -> Option<TxOut> {
        let tx = &self.unsigned_tx;
-        let input = self.inputs.get(input_index)?;

-        match (&input.witness_utxo, &input.non_witness_utxo) {
-            (Some(_), _) => input.witness_utxo.clone(),
-            (_, Some(_)) => input.non_witness_utxo.as_ref().map(|in_tx| {
-                in_tx.output[tx.input[input_index].previous_output.vout as usize].clone()
-            }),
-            _ => None,
+        if input_index >= tx.input.len() {
+            return None;
+        }
+
+        if let Some(input) = self.inputs.get(input_index) {
+            if let Some(wit_utxo) = &input.witness_utxo {
+                Some(wit_utxo.clone())
+            } else if let Some(in_tx) = &input.non_witness_utxo {
+                Some(in_tx.output[tx.input[input_index].previous_output.vout as usize].clone())
+            } else {
+                None
+            }
+        } else {
+            None
        }
    }

@@ -54,13 +61,8 @@ impl PsbtUtils for Psbt {
        let utxos: Option<Vec<TxOut>> = (0..tx.input.len()).map(|i| self.get_utxo_for(i)).collect();

        utxos.map(|inputs| {
-            let input_amount: u64 = inputs.iter().map(|i| i.value.to_sat()).sum();
-            let output_amount: u64 = self
-                .unsigned_tx
-                .output
-                .iter()
-                .map(|o| o.value.to_sat())
-                .sum();
+            let input_amount: u64 = inputs.iter().map(|i| i.value).sum();
+            let output_amount: u64 = self.unsigned_tx.output.iter().map(|o| o.value).sum();
            input_amount
                .checked_sub(output_amount)
                .expect("input amount must be greater than output amount")
@@ -69,7 +71,9 @@ impl PsbtUtils for Psbt {

    fn fee_rate(&self) -> Option<FeeRate> {
        let fee_amount = self.fee_amount();
-        let weight = self.clone().extract_tx().ok()?.weight();
-        fee_amount.map(|fee| Amount::from_sat(fee) / weight)
+        fee_amount.map(|fee| {
+            let weight = self.clone().extract_tx().weight();
+            FeeRate::from_wu(fee, weight)
+        })
    }
 }
--- a/crates/bdk/src/types.rs
+++ b/crates/bdk/src/types.rs
@@ -11,19 +11,20 @@

 use alloc::boxed::Box;
 use core::convert::AsRef;
+use core::ops::Sub;

 use bdk_chain::ConfirmationTime;
-use bitcoin::blockdata::transaction::{OutPoint, Sequence, TxOut};
-use bitcoin::psbt;
+use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxOut};
+use bitcoin::{hash_types::Txid, util::psbt};

 use serde::{Deserialize, Serialize};

 /// Types of keychains
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub enum KeychainKind {
-    /// External keychain, used for deriving recipient addresses.
+    /// External
    External = 0,
-    /// Internal keychain, used for deriving change addresses.
+    /// Internal, usually used for change outputs
    Internal = 1,
 }

@@ -46,11 +47,116 @@ impl AsRef<[u8]> for KeychainKind {
    }
 }

+/// Fee rate
+#[derive(Debug, Copy, Clone, PartialEq, PartialOrd)]
+// Internally stored as satoshi/vbyte
+pub struct FeeRate(f32);
+
+impl FeeRate {
+    /// Create a new instance checking the value provided
+    ///
+    /// ## Panics
+    ///
+    /// Panics if the value is not [normal](https://doc.rust-lang.org/std/primitive.f32.html#method.is_normal) (except if it's a positive zero) or negative.
+    fn new_checked(value: f32) -> Self {
+        assert!(value.is_normal() || value == 0.0);
+        assert!(value.is_sign_positive());
+
+        FeeRate(value)
+    }
+
+    /// Create a new instance of [`FeeRate`] given a float fee rate in sats/kwu
+    pub fn from_sat_per_kwu(sat_per_kwu: f32) -> Self {
+        FeeRate::new_checked(sat_per_kwu / 250.0_f32)
+    }
+
+    /// Create a new instance of [`FeeRate`] given a float fee rate in sats/kvb
+    pub fn from_sat_per_kvb(sat_per_kvb: f32) -> Self {
+        FeeRate::new_checked(sat_per_kvb / 1000.0_f32)
+    }
+
+    /// Create a new instance of [`FeeRate`] given a float fee rate in btc/kvbytes
+    ///
+    /// ## Panics
+    ///
+    /// Panics if the value is not [normal](https://doc.rust-lang.org/std/primitive.f32.html#method.is_normal) (except if it's a positive zero) or negative.
+    pub fn from_btc_per_kvb(btc_per_kvb: f32) -> Self {
+        FeeRate::new_checked(btc_per_kvb * 1e5)
+    }
+
+    /// Create a new instance of [`FeeRate`] given a float fee rate in satoshi/vbyte
+    ///
+    /// ## Panics
+    ///
+    /// Panics if the value is not [normal](https://doc.rust-lang.org/std/primitive.f32.html#method.is_normal) (except if it's a positive zero) or negative.
+    pub fn from_sat_per_vb(sat_per_vb: f32) -> Self {
+        FeeRate::new_checked(sat_per_vb)
+    }
+
+    /// Create a new [`FeeRate`] with the default min relay fee value
+    pub const fn default_min_relay_fee() -> Self {
+        FeeRate(1.0)
+    }
+
+    /// Calculate fee rate from `fee` and weight units (`wu`).
+    pub fn from_wu(fee: u64, wu: usize) -> FeeRate {
+        Self::from_vb(fee, wu.vbytes())
+    }
+
+    /// Calculate fee rate from `fee` and `vbytes`.
+    pub fn from_vb(fee: u64, vbytes: usize) -> FeeRate {
+        let rate = fee as f32 / vbytes as f32;
+        Self::from_sat_per_vb(rate)
+    }
+
+    /// Return the value as satoshi/vbyte
+    pub fn as_sat_per_vb(&self) -> f32 {
+        self.0
+    }
+
+    /// Calculate absolute fee in Satoshis using size in weight units.
+    pub fn fee_wu(&self, wu: usize) -> u64 {
+        self.fee_vb(wu.vbytes())
+    }
+
+    /// Calculate absolute fee in Satoshis using size in virtual bytes.
+    pub fn fee_vb(&self, vbytes: usize) -> u64 {
+        (self.as_sat_per_vb() * vbytes as f32).ceil() as u64
+    }
+}
+
+impl Default for FeeRate {
+    fn default() -> Self {
+        FeeRate::default_min_relay_fee()
+    }
+}
+
+impl Sub for FeeRate {
+    type Output = Self;
+
+    fn sub(self, other: FeeRate) -> Self::Output {
+        FeeRate(self.0 - other.0)
+    }
+}
+
+/// Trait implemented by types that can be used to measure weight units.
+pub trait Vbytes {
+    /// Convert weight units to virtual bytes.
+    fn vbytes(self) -> usize;
+}
+
+impl Vbytes for usize {
+    fn vbytes(self) -> usize {
+        // ref: https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki#transaction-size-calculations
+        (self as f32 / 4.0).ceil() as usize
+    }
+}
+
 /// An unspent output owned by a [`Wallet`].
 ///
 /// [`Wallet`]: crate::Wallet
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Hash)]
-pub struct LocalOutput {
+pub struct LocalUtxo {
    /// Reference to a transaction output
    pub outpoint: OutPoint,
    /// Transaction output
@@ -81,13 +187,11 @@ pub struct WeightedUtxo {
 /// An unspent transaction output (UTXO).
 pub enum Utxo {
    /// A UTXO owned by the local wallet.
-    Local(LocalOutput),
+    Local(LocalUtxo),
    /// A UTXO owned by another wallet.
    Foreign {
        /// The location of the output.
        outpoint: OutPoint,
-        /// The nSequence value to set for this input.
-        sequence: Option<Sequence>,
        /// The information about the input we require to add it to a PSBT.
        // Box it to stop the type being too big.
        psbt_input: Box<psbt::Input>,
@@ -110,7 +214,6 @@ impl Utxo {
            Utxo::Foreign {
                outpoint,
                psbt_input,
-                ..
            } => {
                if let Some(prev_tx) = &psbt_input.non_witness_utxo {
                    return &prev_tx.output[outpoint.vout as usize];
@@ -124,12 +227,107 @@ impl Utxo {
            }
        }
    }
+}

-    /// Get the sequence number if an explicit sequence number has to be set for this input.
-    pub fn sequence(&self) -> Option<Sequence> {
-        match self {
-            Utxo::Local(_) => None,
-            Utxo::Foreign { sequence, .. } => *sequence,
-        }
+/// A wallet transaction
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
+pub struct TransactionDetails {
+    /// Optional transaction
+    pub transaction: Option<Transaction>,
+    /// Transaction id
+    pub txid: Txid,
+    /// Received value (sats)
+    /// Sum of owned outputs of this transaction.
+    pub received: u64,
+    /// Sent value (sats)
+    /// Sum of owned inputs of this transaction.
+    pub sent: u64,
+    /// Fee value in sats if it was available.
+    pub fee: Option<u64>,
+    /// If the transaction is confirmed, contains height and Unix timestamp of the block containing the
+    /// transaction, unconfirmed transaction contains `None`.
+    pub confirmation_time: ConfirmationTime,
+}
+
+impl PartialOrd for TransactionDetails {
+    fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for TransactionDetails {
+    fn cmp(&self, other: &Self) -> core::cmp::Ordering {
+        self.confirmation_time
+            .cmp(&other.confirmation_time)
+            .then_with(|| self.txid.cmp(&other.txid))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn can_store_feerate_in_const() {
+        const _MIN_RELAY: FeeRate = FeeRate::default_min_relay_fee();
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_invalid_feerate_neg_zero() {
+        let _ = FeeRate::from_sat_per_vb(-0.0);
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_invalid_feerate_neg_value() {
+        let _ = FeeRate::from_sat_per_vb(-5.0);
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_invalid_feerate_nan() {
+        let _ = FeeRate::from_sat_per_vb(f32::NAN);
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_invalid_feerate_inf() {
+        let _ = FeeRate::from_sat_per_vb(f32::INFINITY);
+    }
+
+    #[test]
+    fn test_valid_feerate_pos_zero() {
+        let _ = FeeRate::from_sat_per_vb(0.0);
+    }
+
+    #[test]
+    fn test_fee_from_btc_per_kvb() {
+        let fee = FeeRate::from_btc_per_kvb(1e-5);
+        assert!((fee.as_sat_per_vb() - 1.0).abs() < f32::EPSILON);
+    }
+
+    #[test]
+    fn test_fee_from_sat_per_vbyte() {
+        let fee = FeeRate::from_sat_per_vb(1.0);
+        assert!((fee.as_sat_per_vb() - 1.0).abs() < f32::EPSILON);
+    }
+
+    #[test]
+    fn test_fee_default_min_relay_fee() {
+        let fee = FeeRate::default_min_relay_fee();
+        assert!((fee.as_sat_per_vb() - 1.0).abs() < f32::EPSILON);
+    }
+
+    #[test]
+    fn test_fee_from_sat_per_kvb() {
+        let fee = FeeRate::from_sat_per_kvb(1000.0);
+        assert!((fee.as_sat_per_vb() - 1.0).abs() < f32::EPSILON);
+    }
+
+    #[test]
+    fn test_fee_from_sat_per_kwu() {
+        let fee = FeeRate::from_sat_per_kwu(250.0);
+        assert!((fee.as_sat_per_vb() - 1.0).abs() < f32::EPSILON);
    }
 }
--- a/crates/bdk/src/wallet/coin_selection.rs
+++ b/crates/bdk/src/wallet/coin_selection.rs
@@ -26,12 +26,10 @@
 //! ```
 //! # use std::str::FromStr;
 //! # use bitcoin::*;
-//! # use bdk::wallet::{self, ChangeSet, coin_selection::*, coin_selection};
-//! # use bdk::wallet::error::CreateTxError;
-//! # use bdk_chain::PersistBackend;
+//! # use bdk::wallet::{self, coin_selection::*};
 //! # use bdk::*;
 //! # use bdk::wallet::coin_selection::decide_change;
-//! # use anyhow::Error;
+//! # const TXIN_BASE_WEIGHT: usize = (32 + 4 + 4) * 4;
 //! #[derive(Debug)]
 //! struct AlwaysSpendEverything;
 //!
@@ -43,29 +41,25 @@
 //!         fee_rate: FeeRate,
 //!         target_amount: u64,
 //!         drain_script: &Script,
-//!     ) -> Result<CoinSelectionResult, coin_selection::Error> {
+//!     ) -> Result<CoinSelectionResult, bdk::Error> {
 //!         let mut selected_amount = 0;
-//!         let mut additional_weight = Weight::ZERO;
+//!         let mut additional_weight = 0;
 //!         let all_utxos_selected = required_utxos
 //!             .into_iter()
 //!             .chain(optional_utxos)
 //!             .scan(
 //!                 (&mut selected_amount, &mut additional_weight),
 //!                 |(selected_amount, additional_weight), weighted_utxo| {
-//!                     **selected_amount += weighted_utxo.utxo.txout().value.to_sat();
-//!                     **additional_weight += Weight::from_wu(
-//!                         (TxIn::default().segwit_weight().to_wu()
-//!                             + weighted_utxo.satisfaction_weight as u64)
-//!                             as u64,
-//!                     );
+//!                     **selected_amount += weighted_utxo.utxo.txout().value;
+//!                     **additional_weight += TXIN_BASE_WEIGHT + weighted_utxo.satisfaction_weight;
 //!                     Some(weighted_utxo.utxo)
 //!                 },
 //!             )
 //!             .collect::<Vec<_>>();
-//!         let additional_fees = (fee_rate * additional_weight).to_sat();
+//!         let additional_fees = fee_rate.fee_wu(additional_weight);
 //!         let amount_needed_with_fees = additional_fees + target_amount;
 //!         if selected_amount < amount_needed_with_fees {
-//!             return Err(coin_selection::Error::InsufficientFunds {
+//!             return Err(bdk::Error::InsufficientFunds {
 //!                 needed: amount_needed_with_fees,
 //!                 available: selected_amount,
 //!             });
@@ -86,11 +80,8 @@
 //! # let mut wallet = doctest_wallet!();
 //! // create wallet, sync, ...
 //!
-//! let to_address = Address::from_str("2N4eQYCbKUHCCTUjBJeHcJp9ok6J2GZsTDt")
-//!     .unwrap()
-//!     .require_network(Network::Testnet)
-//!     .unwrap();
-//! let psbt = {
+//! let to_address = Address::from_str("2N4eQYCbKUHCCTUjBJeHcJp9ok6J2GZsTDt").unwrap();
+//! let (psbt, details) = {
 //!     let mut builder = wallet.build_tx().coin_selection(AlwaysSpendEverything);
 //!     builder.add_recipient(to_address.script_pubkey(), 50_000);
 //!     builder.finish()?
@@ -98,65 +89,28 @@
 //!
 //! // inspect, sign, broadcast, ...
 //!
-//! # Ok::<(), anyhow::Error>(())
+//! # Ok::<(), bdk::Error>(())
 //! ```

-use crate::chain::collections::HashSet;
+use crate::types::FeeRate;
 use crate::wallet::utils::IsDust;
-use crate::Utxo;
 use crate::WeightedUtxo;
-use bitcoin::FeeRate;
+use crate::{error::Error, Utxo};

 use alloc::vec::Vec;
 use bitcoin::consensus::encode::serialize;
-use bitcoin::OutPoint;
-use bitcoin::TxIn;
-use bitcoin::{Script, Weight};
+use bitcoin::Script;

 use core::convert::TryInto;
-use core::fmt::{self, Formatter};
 use rand::seq::SliceRandom;

 /// Default coin selection algorithm used by [`TxBuilder`](super::tx_builder::TxBuilder) if not
 /// overridden
 pub type DefaultCoinSelectionAlgorithm = BranchAndBoundCoinSelection;

-/// Errors that can be thrown by the [`coin_selection`](crate::wallet::coin_selection) module
-#[derive(Debug)]
-pub enum Error {
-    /// Wallet's UTXO set is not enough to cover recipient's requested plus fee
-    InsufficientFunds {
-        /// Sats needed for some transaction
-        needed: u64,
-        /// Sats available for spending
-        available: u64,
-    },
-    /// Branch and bound coin selection tries to avoid needing a change by finding the right inputs for
-    /// the desired outputs plus fee, if there is not such combination this error is thrown
-    BnBNoExactMatch,
-    /// Branch and bound coin selection possible attempts with sufficiently big UTXO set could grow
-    /// exponentially, thus a limit is set, and when hit, this error is thrown
-    BnBTotalTriesExceeded,
-}
-
-impl fmt::Display for Error {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::InsufficientFunds { needed, available } => write!(
-                f,
-                "Insufficient funds: {} sat available of {} sat needed",
-                available, needed
-            ),
-            Self::BnBTotalTriesExceeded => {
-                write!(f, "Branch and bound coin selection: total tries exceeded")
-            }
-            Self::BnBNoExactMatch => write!(f, "Branch and bound coin selection: not exact match"),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for Error {}
+// Base weight of a Txin, not counting the weight needed for satisfying it.
+// prev_txid (32 bytes) + prev_vout (4 bytes) + sequence (4 bytes)
+pub(crate) const TXIN_BASE_WEIGHT: usize = (32 + 4 + 4) * 4;

 #[derive(Debug)]
 /// Remaining amount after performing coin selection
@@ -193,7 +147,7 @@ pub struct CoinSelectionResult {
 impl CoinSelectionResult {
    /// The total value of the inputs selected.
    pub fn selected_amount(&self) -> u64 {
-        self.selected.iter().map(|u| u.txout().value.to_sat()).sum()
+        self.selected.iter().map(|u| u.txout().value).sum()
    }

    /// The total value of the inputs selected from the local wallet.
@@ -201,7 +155,7 @@ impl CoinSelectionResult {
        self.selected
            .iter()
            .filter_map(|u| match u {
-                Utxo::Local(_) => Some(u.txout().value.to_sat()),
+                Utxo::Local(_) => Some(u.txout().value),
                _ => None,
            })
            .sum()
@@ -254,6 +208,12 @@ impl CoinSelectionAlgorithm for LargestFirstCoinSelection {
        target_amount: u64,
        drain_script: &Script,
    ) -> Result<CoinSelectionResult, Error> {
+        log::debug!(
+            "target_amount = `{}`, fee_rate = `{:?}`",
+            target_amount,
+            fee_rate
+        );
+
        // We put the "required UTXOs" first and make sure the optional UTXOs are sorted,
        // initially smallest to largest, before being reversed with `.rev()`.
        let utxos = {
@@ -311,8 +271,7 @@ impl CoinSelectionAlgorithm for OldestFirstCoinSelection {
 pub fn decide_change(remaining_amount: u64, fee_rate: FeeRate, drain_script: &Script) -> Excess {
    // drain_output_len = size(len(script_pubkey)) + len(script_pubkey) + size(output_value)
    let drain_output_len = serialize(drain_script).len() + 8usize;
-    let change_fee =
-        (fee_rate * Weight::from_vb(drain_output_len as u64).expect("overflow occurred")).to_sat();
+    let change_fee = fee_rate.fee_vb(drain_output_len);
    let drain_val = remaining_amount.saturating_sub(change_fee);

    if drain_val.is_dust(drain_script) {
@@ -343,13 +302,16 @@ fn select_sorted_utxos(
            (&mut selected_amount, &mut fee_amount),
            |(selected_amount, fee_amount), (must_use, weighted_utxo)| {
                if must_use || **selected_amount < target_amount + **fee_amount {
-                    **fee_amount += (fee_rate
-                        * Weight::from_wu(
-                            TxIn::default().segwit_weight().to_wu()
-                                + weighted_utxo.satisfaction_weight as u64,
-                        ))
-                    .to_sat();
-                    **selected_amount += weighted_utxo.utxo.txout().value.to_sat();
+                    **fee_amount +=
+                        fee_rate.fee_wu(TXIN_BASE_WEIGHT + weighted_utxo.satisfaction_weight);
+                    **selected_amount += weighted_utxo.utxo.txout().value;
+
+                    log::debug!(
+                        "Selected {}, updated fee_amount = `{}`",
+                        weighted_utxo.utxo.outpoint(),
+                        fee_amount
+                    );
+
                    Some(weighted_utxo.utxo)
                } else {
                    None
@@ -389,12 +351,8 @@ struct OutputGroup {

 impl OutputGroup {
    fn new(weighted_utxo: WeightedUtxo, fee_rate: FeeRate) -> Self {
-        let fee = (fee_rate
-            * Weight::from_wu(
-                TxIn::default().segwit_weight().to_wu() + weighted_utxo.satisfaction_weight as u64,
-            ))
-        .to_sat();
-        let effective_value = weighted_utxo.utxo.txout().value.to_sat() as i64 - fee as i64;
+        let fee = fee_rate.fee_wu(TXIN_BASE_WEIGHT + weighted_utxo.satisfaction_weight);
+        let effective_value = weighted_utxo.utxo.txout().value as i64 - fee as i64;
        OutputGroup {
            weighted_utxo,
            fee,
@@ -460,8 +418,7 @@ impl CoinSelectionAlgorithm for BranchAndBoundCoinSelection {
            .iter()
            .fold(0, |acc, x| acc + x.effective_value);

-        let cost_of_change =
-            (Weight::from_vb(self.size_of_change).expect("overflow occurred") * fee_rate).to_sat();
+        let cost_of_change = self.size_of_change as f32 * fee_rate.as_sat_per_vb();

        // `curr_value` and `curr_available_value` are both the sum of *effective_values* of
        // the UTXOs. For the optional UTXOs (curr_available_value) we filter out UTXOs with
@@ -485,7 +442,7 @@ impl CoinSelectionAlgorithm for BranchAndBoundCoinSelection {
                    .chain(optional_utxos.iter())
                    .fold((0, 0), |(mut fees, mut value), utxo| {
                        fees += utxo.fee;
-                        value += utxo.weighted_utxo.utxo.txout().value.to_sat();
+                        value += utxo.weighted_utxo.utxo.txout().value;

                        (fees, value)
                    });
@@ -552,7 +509,7 @@ impl BranchAndBoundCoinSelection {
        mut curr_value: i64,
        mut curr_available_value: i64,
        target_amount: i64,
-        cost_of_change: u64,
+        cost_of_change: f32,
        drain_script: &Script,
        fee_rate: FeeRate,
    ) -> Result<CoinSelectionResult, Error> {
@@ -589,7 +546,7 @@ impl BranchAndBoundCoinSelection {
                // If we found a solution better than the previous one, or if there wasn't previous
                // solution, update the best solution
                if best_selection_value.is_none() || curr_value < best_selection_value.unwrap() {
-                    best_selection.clone_from(&current_selection);
+                    best_selection = current_selection.clone();
                    best_selection_value = Some(curr_value);
                }

@@ -718,44 +675,25 @@ impl BranchAndBoundCoinSelection {
    }
 }

-/// Remove duplicate UTXOs.
-///
-/// If a UTXO appears in both `required` and `optional`, the appearance in `required` is kept.
-pub(crate) fn filter_duplicates<I>(required: I, optional: I) -> (I, I)
-where
-    I: IntoIterator<Item = WeightedUtxo> + FromIterator<WeightedUtxo>,
-{
-    let mut visited = HashSet::<OutPoint>::new();
-    let required = required
-        .into_iter()
-        .filter(|utxo| visited.insert(utxo.utxo.outpoint()))
-        .collect::<I>();
-    let optional = optional
-        .into_iter()
-        .filter(|utxo| visited.insert(utxo.utxo.outpoint()))
-        .collect::<I>();
-    (required, optional)
-}
-
 #[cfg(test)]
 mod test {
    use assert_matches::assert_matches;
    use core::str::FromStr;

    use bdk_chain::ConfirmationTime;
-    use bitcoin::{Amount, ScriptBuf, TxIn, TxOut};
+    use bitcoin::{OutPoint, Script, TxOut};

    use super::*;
    use crate::types::*;
-    use crate::wallet::coin_selection::filter_duplicates;
+    use crate::wallet::Vbytes;

    use rand::rngs::StdRng;
    use rand::seq::SliceRandom;
    use rand::{Rng, RngCore, SeedableRng};

-    // signature len (1WU) + signature and sighash (72WU)
-    // + pubkey len (1WU) + pubkey (33WU)
-    const P2WPKH_SATISFACTION_SIZE: usize = 1 + 72 + 1 + 33;
+    // n. of items on witness (1WU) + signature len (1WU) + signature and sighash (72WU)
+    // + pubkey len (1WU) + pubkey (33WU) + script sig len (1 byte, 4WU)
+    const P2WPKH_SATISFACTION_SIZE: usize = 1 + 1 + 72 + 1 + 33 + 4;

    const FEE_AMOUNT: u64 = 50;

@@ -768,11 +706,11 @@ mod test {
        .unwrap();
        WeightedUtxo {
            satisfaction_weight: P2WPKH_SATISFACTION_SIZE,
-            utxo: Utxo::Local(LocalOutput {
+            utxo: Utxo::Local(LocalUtxo {
                outpoint,
                txout: TxOut {
-                    value: Amount::from_sat(value),
-                    script_pubkey: ScriptBuf::new(),
+                    value,
+                    script_pubkey: Script::new(),
                },
                keychain: KeychainKind::External,
                is_spent: false,
@@ -784,13 +722,9 @@ mod test {

    fn get_test_utxos() -> Vec<WeightedUtxo> {
        vec![
-            utxo(100_000, 0, ConfirmationTime::Unconfirmed { last_seen: 0 }),
-            utxo(
-                FEE_AMOUNT - 40,
-                1,
-                ConfirmationTime::Unconfirmed { last_seen: 0 },
-            ),
-            utxo(200_000, 2, ConfirmationTime::Unconfirmed { last_seen: 0 }),
+            utxo(100_000, 0, ConfirmationTime::Unconfirmed),
+            utxo(FEE_AMOUNT - 40, 1, ConfirmationTime::Unconfirmed),
+            utxo(200_000, 2, ConfirmationTime::Unconfirmed),
        ]
    }

@@ -825,18 +759,17 @@ mod test {

    fn generate_random_utxos(rng: &mut StdRng, utxos_number: usize) -> Vec<WeightedUtxo> {
        let mut res = Vec::new();
-        for i in 0..utxos_number {
+        for _ in 0..utxos_number {
            res.push(WeightedUtxo {
                satisfaction_weight: P2WPKH_SATISFACTION_SIZE,
-                utxo: Utxo::Local(LocalOutput {
-                    outpoint: OutPoint::from_str(&format!(
-                        "ebd9813ecebc57ff8f30797de7c205e3c7498ca950ea4341ee51a685ff2fa30a:{}",
-                        i
-                    ))
+                utxo: Utxo::Local(LocalUtxo {
+                    outpoint: OutPoint::from_str(
+                        "ebd9813ecebc57ff8f30797de7c205e3c7498ca950ea4341ee51a685ff2fa30a:0",
+                    )
                    .unwrap(),
                    txout: TxOut {
-                        value: Amount::from_sat(rng.gen_range(0..200000000)),
-                        script_pubkey: ScriptBuf::new(),
+                        value: rng.gen_range(0..200000000),
+                        script_pubkey: Script::new(),
                    },
                    keychain: KeychainKind::External,
                    is_spent: false,
@@ -847,7 +780,7 @@ mod test {
                            time: rng.next_u64(),
                        }
                    } else {
-                        ConfirmationTime::Unconfirmed { last_seen: 0 }
+                        ConfirmationTime::Unconfirmed
                    },
                }),
            });
@@ -856,26 +789,24 @@ mod test {
    }

    fn generate_same_value_utxos(utxos_value: u64, utxos_number: usize) -> Vec<WeightedUtxo> {
-        (0..utxos_number)
-            .map(|i| WeightedUtxo {
-                satisfaction_weight: P2WPKH_SATISFACTION_SIZE,
-                utxo: Utxo::Local(LocalOutput {
-                    outpoint: OutPoint::from_str(&format!(
-                        "ebd9813ecebc57ff8f30797de7c205e3c7498ca950ea4341ee51a685ff2fa30a:{}",
-                        i
-                    ))
-                    .unwrap(),
-                    txout: TxOut {
-                        value: Amount::from_sat(utxos_value),
-                        script_pubkey: ScriptBuf::new(),
-                    },
-                    keychain: KeychainKind::External,
-                    is_spent: false,
-                    derivation_index: 42,
-                    confirmation_time: ConfirmationTime::Unconfirmed { last_seen: 0 },
-                }),
-            })
-            .collect()
+        let utxo = WeightedUtxo {
+            satisfaction_weight: P2WPKH_SATISFACTION_SIZE,
+            utxo: Utxo::Local(LocalUtxo {
+                outpoint: OutPoint::from_str(
+                    "ebd9813ecebc57ff8f30797de7c205e3c7498ca950ea4341ee51a685ff2fa30a:0",
+                )
+                .unwrap(),
+                txout: TxOut {
+                    value: utxos_value,
+                    script_pubkey: Script::new(),
+                },
+                keychain: KeychainKind::External,
+                is_spent: false,
+                derivation_index: 42,
+                confirmation_time: ConfirmationTime::Unconfirmed,
+            }),
+        };
+        vec![utxo; utxos_number]
    }

    fn sum_random_utxos(mut rng: &mut StdRng, utxos: &mut Vec<WeightedUtxo>) -> u64 {
@@ -883,21 +814,21 @@ mod test {
        utxos.shuffle(&mut rng);
        utxos[..utxos_picked_len]
            .iter()
-            .map(|u| u.utxo.txout().value.to_sat())
+            .map(|u| u.utxo.txout().value)
            .sum()
    }

    #[test]
    fn test_largest_first_coin_selection_success() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 250_000 + FEE_AMOUNT;

-        let result = LargestFirstCoinSelection
+        let result = LargestFirstCoinSelection::default()
            .coin_select(
                utxos,
                vec![],
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -911,14 +842,14 @@ mod test {
    #[test]
    fn test_largest_first_coin_selection_use_all() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 20_000 + FEE_AMOUNT;

-        let result = LargestFirstCoinSelection
+        let result = LargestFirstCoinSelection::default()
            .coin_select(
                utxos,
                vec![],
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -932,14 +863,14 @@ mod test {
    #[test]
    fn test_largest_first_coin_selection_use_only_necessary() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 20_000 + FEE_AMOUNT;

-        let result = LargestFirstCoinSelection
+        let result = LargestFirstCoinSelection::default()
            .coin_select(
                vec![],
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -954,14 +885,14 @@ mod test {
    #[should_panic(expected = "InsufficientFunds")]
    fn test_largest_first_coin_selection_insufficient_funds() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 500_000 + FEE_AMOUNT;

-        LargestFirstCoinSelection
+        LargestFirstCoinSelection::default()
            .coin_select(
                vec![],
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -972,14 +903,14 @@ mod test {
    #[should_panic(expected = "InsufficientFunds")]
    fn test_largest_first_coin_selection_insufficient_funds_high_fees() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 250_000 + FEE_AMOUNT;

-        LargestFirstCoinSelection
+        LargestFirstCoinSelection::default()
            .coin_select(
                vec![],
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1000),
+                FeeRate::from_sat_per_vb(1000.0),
                target_amount,
                &drain_script,
            )
@@ -989,14 +920,14 @@ mod test {
    #[test]
    fn test_oldest_first_coin_selection_success() {
        let utxos = get_oldest_first_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 180_000 + FEE_AMOUNT;

-        let result = OldestFirstCoinSelection
+        let result = OldestFirstCoinSelection::default()
            .coin_select(
                vec![],
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -1010,14 +941,14 @@ mod test {
    #[test]
    fn test_oldest_first_coin_selection_use_all() {
        let utxos = get_oldest_first_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 20_000 + FEE_AMOUNT;

-        let result = OldestFirstCoinSelection
+        let result = OldestFirstCoinSelection::default()
            .coin_select(
                utxos,
                vec![],
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -1031,14 +962,14 @@ mod test {
    #[test]
    fn test_oldest_first_coin_selection_use_only_necessary() {
        let utxos = get_oldest_first_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 20_000 + FEE_AMOUNT;

-        let result = OldestFirstCoinSelection
+        let result = OldestFirstCoinSelection::default()
            .coin_select(
                vec![],
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -1053,14 +984,14 @@ mod test {
    #[should_panic(expected = "InsufficientFunds")]
    fn test_oldest_first_coin_selection_insufficient_funds() {
        let utxos = get_oldest_first_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 600_000 + FEE_AMOUNT;

-        OldestFirstCoinSelection
+        OldestFirstCoinSelection::default()
            .coin_select(
                vec![],
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -1072,18 +1003,14 @@ mod test {
    fn test_oldest_first_coin_selection_insufficient_funds_high_fees() {
        let utxos = get_oldest_first_test_utxos();

-        let target_amount: u64 = utxos
-            .iter()
-            .map(|wu| wu.utxo.txout().value.to_sat())
-            .sum::<u64>()
-            - 50;
-        let drain_script = ScriptBuf::default();
+        let target_amount: u64 = utxos.iter().map(|wu| wu.utxo.txout().value).sum::<u64>() - 50;
+        let drain_script = Script::default();

-        OldestFirstCoinSelection
+        OldestFirstCoinSelection::default()
            .coin_select(
                vec![],
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1000),
+                FeeRate::from_sat_per_vb(1000.0),
                target_amount,
                &drain_script,
            )
@@ -1096,7 +1023,7 @@ mod test {
        // select three outputs
        let utxos = generate_same_value_utxos(100_000, 20);

-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();

        let target_amount = 250_000 + FEE_AMOUNT;

@@ -1104,7 +1031,7 @@ mod test {
            .coin_select(
                vec![],
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -1118,14 +1045,14 @@ mod test {
    #[test]
    fn test_bnb_coin_selection_required_are_enough() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 20_000 + FEE_AMOUNT;

        let result = BranchAndBoundCoinSelection::default()
            .coin_select(
                utxos.clone(),
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -1139,14 +1066,14 @@ mod test {
    #[test]
    fn test_bnb_coin_selection_optional_are_enough() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 299756 + FEE_AMOUNT;

        let result = BranchAndBoundCoinSelection::default()
            .coin_select(
                vec![],
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -1164,18 +1091,14 @@ mod test {

        let required = vec![utxos[0].clone()];
        let mut optional = utxos[1..].to_vec();
-        optional.push(utxo(
-            500_000,
-            3,
-            ConfirmationTime::Unconfirmed { last_seen: 0 },
-        ));
+        optional.push(utxo(500_000, 3, ConfirmationTime::Unconfirmed));

        // Defensive assertions, for sanity and in case someone changes the test utxos vector.
-        let amount: u64 = required.iter().map(|u| u.utxo.txout().value.to_sat()).sum();
+        let amount: u64 = required.iter().map(|u| u.utxo.txout().value).sum();
        assert_eq!(amount, 100_000);
-        let amount: u64 = optional.iter().map(|u| u.utxo.txout().value.to_sat()).sum();
+        let amount: u64 = optional.iter().map(|u| u.utxo.txout().value).sum();
        assert!(amount > 150_000);
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();

        let target_amount = 150_000 + FEE_AMOUNT;

@@ -1183,7 +1106,7 @@ mod test {
            .coin_select(
                required,
                optional,
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -1198,14 +1121,14 @@ mod test {
    #[should_panic(expected = "InsufficientFunds")]
    fn test_bnb_coin_selection_insufficient_funds() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 500_000 + FEE_AMOUNT;

        BranchAndBoundCoinSelection::default()
            .coin_select(
                vec![],
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1),
+                FeeRate::from_sat_per_vb(1.0),
                target_amount,
                &drain_script,
            )
@@ -1216,14 +1139,14 @@ mod test {
    #[should_panic(expected = "InsufficientFunds")]
    fn test_bnb_coin_selection_insufficient_funds_high_fees() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 250_000 + FEE_AMOUNT;

        BranchAndBoundCoinSelection::default()
            .coin_select(
                vec![],
                utxos,
-                FeeRate::from_sat_per_vb_unchecked(1000),
+                FeeRate::from_sat_per_vb(1000.0),
                target_amount,
                &drain_script,
            )
@@ -1233,21 +1156,24 @@ mod test {
    #[test]
    fn test_bnb_coin_selection_check_fee_rate() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 99932; // first utxo's effective value
-        let feerate = FeeRate::BROADCAST_MIN;

        let result = BranchAndBoundCoinSelection::new(0)
-            .coin_select(vec![], utxos, feerate, target_amount, &drain_script)
+            .coin_select(
+                vec![],
+                utxos,
+                FeeRate::from_sat_per_vb(1.0),
+                target_amount,
+                &drain_script,
+            )
            .unwrap();

        assert_eq!(result.selected.len(), 1);
        assert_eq!(result.selected_amount(), 100_000);
-        let input_weight =
-            TxIn::default().segwit_weight().to_wu() + P2WPKH_SATISFACTION_SIZE as u64;
+        let input_size = (TXIN_BASE_WEIGHT + P2WPKH_SATISFACTION_SIZE).vbytes();
        // the final fee rate should be exactly the same as the fee rate given
-        let result_feerate = Amount::from_sat(result.fee_amount) / Weight::from_wu(input_weight);
-        assert_eq!(result_feerate, feerate);
+        assert!((1.0 - (result.fee_amount as f32 / input_size as f32)).abs() < f32::EPSILON);
    }

    #[test]
@@ -1258,12 +1184,12 @@ mod test {
        for _i in 0..200 {
            let mut optional_utxos = generate_random_utxos(&mut rng, 16);
            let target_amount = sum_random_utxos(&mut rng, &mut optional_utxos);
-            let drain_script = ScriptBuf::default();
+            let drain_script = Script::default();
            let result = BranchAndBoundCoinSelection::new(0)
                .coin_select(
                    vec![],
                    optional_utxos,
-                    FeeRate::ZERO,
+                    FeeRate::from_sat_per_vb(0.0),
                    target_amount,
                    &drain_script,
                )
@@ -1275,7 +1201,7 @@ mod test {
    #[test]
    #[should_panic(expected = "BnBNoExactMatch")]
    fn test_bnb_function_no_exact_match() {
-        let fee_rate = FeeRate::from_sat_per_vb_unchecked(10);
+        let fee_rate = FeeRate::from_sat_per_vb(10.0);
        let utxos: Vec<OutputGroup> = get_test_utxos()
            .into_iter()
            .map(|u| OutputGroup::new(u, fee_rate))
@@ -1284,9 +1210,9 @@ mod test {
        let curr_available_value = utxos.iter().fold(0, |acc, x| acc + x.effective_value);

        let size_of_change = 31;
-        let cost_of_change = (Weight::from_vb_unchecked(size_of_change) * fee_rate).to_sat();
+        let cost_of_change = size_of_change as f32 * fee_rate.as_sat_per_vb();

-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();
        let target_amount = 20_000 + FEE_AMOUNT;
        BranchAndBoundCoinSelection::new(size_of_change)
            .bnb(
@@ -1305,7 +1231,7 @@ mod test {
    #[test]
    #[should_panic(expected = "BnBTotalTriesExceeded")]
    fn test_bnb_function_tries_exceeded() {
-        let fee_rate = FeeRate::from_sat_per_vb_unchecked(10);
+        let fee_rate = FeeRate::from_sat_per_vb(10.0);
        let utxos: Vec<OutputGroup> = generate_same_value_utxos(100_000, 100_000)
            .into_iter()
            .map(|u| OutputGroup::new(u, fee_rate))
@@ -1314,10 +1240,10 @@ mod test {
        let curr_available_value = utxos.iter().fold(0, |acc, x| acc + x.effective_value);

        let size_of_change = 31;
-        let cost_of_change = (Weight::from_vb_unchecked(size_of_change) * fee_rate).to_sat();
+        let cost_of_change = size_of_change as f32 * fee_rate.as_sat_per_vb();
        let target_amount = 20_000 + FEE_AMOUNT;

-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();

        BranchAndBoundCoinSelection::new(size_of_change)
            .bnb(
@@ -1336,9 +1262,9 @@ mod test {
    // The match won't be exact but still in the range
    #[test]
    fn test_bnb_function_almost_exact_match_with_fees() {
-        let fee_rate = FeeRate::from_sat_per_vb_unchecked(1);
+        let fee_rate = FeeRate::from_sat_per_vb(1.0);
        let size_of_change = 31;
-        let cost_of_change = (Weight::from_vb_unchecked(size_of_change) * fee_rate).to_sat();
+        let cost_of_change = size_of_change as f32 * fee_rate.as_sat_per_vb();

        let utxos: Vec<_> = generate_same_value_utxos(50_000, 10)
            .into_iter()
@@ -1351,9 +1277,9 @@ mod test {

        // 2*(value of 1 utxo)  - 2*(1 utxo fees with 1.0sat/vbyte fee rate) -
        // cost_of_change + 5.
-        let target_amount = 2 * 50_000 - 2 * 67 - cost_of_change as i64 + 5;
+        let target_amount = 2 * 50_000 - 2 * 67 - cost_of_change.ceil() as i64 + 5;

-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();

        let result = BranchAndBoundCoinSelection::new(size_of_change)
            .bnb(
@@ -1376,7 +1302,7 @@ mod test {
    fn test_bnb_function_exact_match_more_utxos() {
        let seed = [0; 32];
        let mut rng: StdRng = SeedableRng::from_seed(seed);
-        let fee_rate = FeeRate::ZERO;
+        let fee_rate = FeeRate::from_sat_per_vb(0.0);

        for _ in 0..200 {
            let optional_utxos: Vec<_> = generate_random_utxos(&mut rng, 40)
@@ -1393,7 +1319,7 @@ mod test {
            let target_amount =
                optional_utxos[3].effective_value + optional_utxos[23].effective_value;

-            let drain_script = ScriptBuf::default();
+            let drain_script = Script::default();

            let result = BranchAndBoundCoinSelection::new(0)
                .bnb(
@@ -1402,7 +1328,7 @@ mod test {
                    curr_value,
                    curr_available_value,
                    target_amount,
-                    0,
+                    0.0,
                    &drain_script,
                    fee_rate,
                )
@@ -1418,13 +1344,13 @@ mod test {
        let mut utxos = generate_random_utxos(&mut rng, 300);
        let target_amount = sum_random_utxos(&mut rng, &mut utxos) + FEE_AMOUNT;

-        let fee_rate = FeeRate::from_sat_per_vb_unchecked(1);
+        let fee_rate = FeeRate::from_sat_per_vb(1.0);
        let utxos: Vec<OutputGroup> = utxos
            .into_iter()
            .map(|u| OutputGroup::new(u, fee_rate))
            .collect();

-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();

        let result = BranchAndBoundCoinSelection::default().single_random_draw(
            vec![],
@@ -1442,12 +1368,12 @@ mod test {
    #[test]
    fn test_bnb_exclude_negative_effective_value() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();

        let selection = BranchAndBoundCoinSelection::default().coin_select(
            vec![],
            utxos,
-            FeeRate::from_sat_per_vb_unchecked(10),
+            FeeRate::from_sat_per_vb(10.0),
            500_000,
            &drain_script,
        );
@@ -1464,16 +1390,16 @@ mod test {
    #[test]
    fn test_bnb_include_negative_effective_value_when_required() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();

-        let (required, optional) = utxos.into_iter().partition(
-            |u| matches!(u, WeightedUtxo { utxo, .. } if utxo.txout().value.to_sat() < 1000),
-        );
+        let (required, optional) = utxos
+            .into_iter()
+            .partition(|u| matches!(u, WeightedUtxo { utxo, .. } if utxo.txout().value < 1000));

        let selection = BranchAndBoundCoinSelection::default().coin_select(
            required,
            optional,
-            FeeRate::from_sat_per_vb_unchecked(10),
+            FeeRate::from_sat_per_vb(10.0),
            500_000,
            &drain_script,
        );
@@ -1490,12 +1416,12 @@ mod test {
    #[test]
    fn test_bnb_sum_of_effective_value_negative() {
        let utxos = get_test_utxos();
-        let drain_script = ScriptBuf::default();
+        let drain_script = Script::default();

        let selection = BranchAndBoundCoinSelection::default().coin_select(
            utxos,
            vec![],
-            FeeRate::from_sat_per_vb_unchecked(10_000),
+            FeeRate::from_sat_per_vb(10_000.0),
            500_000,
            &drain_script,
        );
@@ -1508,95 +1434,4 @@ mod test {
            })
        );
    }
-
-    #[test]
-    fn test_filter_duplicates() {
-        fn utxo(txid: &str, value: u64) -> WeightedUtxo {
-            WeightedUtxo {
-                satisfaction_weight: 0,
-                utxo: Utxo::Local(LocalOutput {
-                    outpoint: OutPoint::new(bitcoin::hashes::Hash::hash(txid.as_bytes()), 0),
-                    txout: TxOut {
-                        value: Amount::from_sat(value),
-                        script_pubkey: ScriptBuf::new(),
-                    },
-                    keychain: KeychainKind::External,
-                    is_spent: false,
-                    derivation_index: 0,
-                    confirmation_time: ConfirmationTime::Confirmed {
-                        height: 12345,
-                        time: 12345,
-                    },
-                }),
-            }
-        }
-
-        fn to_utxo_vec(utxos: &[(&str, u64)]) -> Vec<WeightedUtxo> {
-            let mut v = utxos
-                .iter()
-                .map(|&(txid, value)| utxo(txid, value))
-                .collect::<Vec<_>>();
-            v.sort_by_key(|u| u.utxo.outpoint());
-            v
-        }
-
-        struct TestCase<'a> {
-            name: &'a str,
-            required: &'a [(&'a str, u64)],
-            optional: &'a [(&'a str, u64)],
-            exp_required: &'a [(&'a str, u64)],
-            exp_optional: &'a [(&'a str, u64)],
-        }
-
-        let test_cases = [
-            TestCase {
-                name: "no_duplicates",
-                required: &[("A", 1000), ("B", 2100)],
-                optional: &[("C", 1000)],
-                exp_required: &[("A", 1000), ("B", 2100)],
-                exp_optional: &[("C", 1000)],
-            },
-            TestCase {
-                name: "duplicate_required_utxos",
-                required: &[("A", 3000), ("B", 1200), ("C", 1234), ("A", 3000)],
-                optional: &[("D", 2100)],
-                exp_required: &[("A", 3000), ("B", 1200), ("C", 1234)],
-                exp_optional: &[("D", 2100)],
-            },
-            TestCase {
-                name: "duplicate_optional_utxos",
-                required: &[("A", 3000), ("B", 1200)],
-                optional: &[("C", 5000), ("D", 1300), ("C", 5000)],
-                exp_required: &[("A", 3000), ("B", 1200)],
-                exp_optional: &[("C", 5000), ("D", 1300)],
-            },
-            TestCase {
-                name: "duplicate_across_required_and_optional_utxos",
-                required: &[("A", 3000), ("B", 1200), ("C", 2100)],
-                optional: &[("A", 3000), ("D", 1200), ("E", 5000)],
-                exp_required: &[("A", 3000), ("B", 1200), ("C", 2100)],
-                exp_optional: &[("D", 1200), ("E", 5000)],
-            },
-        ];
-
-        for (i, t) in test_cases.into_iter().enumerate() {
-            println!("Case {}: {}", i, t.name);
-            let (required, optional) =
-                filter_duplicates(to_utxo_vec(t.required), to_utxo_vec(t.optional));
-            assert_eq!(
-                required,
-                to_utxo_vec(t.exp_required),
-                "[{}:{}] unexpected `required` result",
-                i,
-                t.name
-            );
-            assert_eq!(
-                optional,
-                to_utxo_vec(t.exp_optional),
-                "[{}:{}] unexpected `optional` result",
-                i,
-                t.name
-            );
-        }
-    }
 }
--- a/crates/bdk/src/wallet/error.rs
+++ b/crates/bdk/src/wallet/error.rs
@@ -1,294 +0,0 @@
-// Bitcoin Dev Kit
-// Written in 2020 by Alekos Filini <alekos.filini@gmail.com>
-//
-// Copyright (c) 2020-2021 Bitcoin Dev Kit Developers
-//
-// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
-// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
-// You may not use this file except in accordance with one or both of these
-// licenses.
-
-//! Errors that can be thrown by the [`Wallet`](crate::wallet::Wallet)
-
-use crate::descriptor::policy::PolicyError;
-use crate::descriptor::DescriptorError;
-use crate::wallet::coin_selection;
-use crate::{descriptor, KeychainKind};
-use alloc::string::String;
-use bitcoin::{absolute, psbt, OutPoint, Sequence, Txid};
-use core::fmt;
-
-/// Errors returned by miniscript when updating inconsistent PSBTs
-#[derive(Debug, Clone)]
-pub enum MiniscriptPsbtError {
-    /// Descriptor key conversion error
-    Conversion(miniscript::descriptor::ConversionError),
-    /// Return error type for PsbtExt::update_input_with_descriptor
-    UtxoUpdate(miniscript::psbt::UtxoUpdateError),
-    /// Return error type for PsbtExt::update_output_with_descriptor
-    OutputUpdate(miniscript::psbt::OutputUpdateError),
-}
-
-impl fmt::Display for MiniscriptPsbtError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Conversion(err) => write!(f, "Conversion error: {}", err),
-            Self::UtxoUpdate(err) => write!(f, "UTXO update error: {}", err),
-            Self::OutputUpdate(err) => write!(f, "Output update error: {}", err),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for MiniscriptPsbtError {}
-
-#[derive(Debug)]
-/// Error returned from [`TxBuilder::finish`]
-///
-/// [`TxBuilder::finish`]: crate::wallet::tx_builder::TxBuilder::finish
-pub enum CreateTxError<P> {
-    /// There was a problem with the descriptors passed in
-    Descriptor(DescriptorError),
-    /// We were unable to write wallet data to the persistence backend
-    Persist(P),
-    /// There was a problem while extracting and manipulating policies
-    Policy(PolicyError),
-    /// Spending policy is not compatible with this [`KeychainKind`]
-    SpendingPolicyRequired(KeychainKind),
-    /// Requested invalid transaction version '0'
-    Version0,
-    /// Requested transaction version `1`, but at least `2` is needed to use OP_CSV
-    Version1Csv,
-    /// Requested `LockTime` is less than is required to spend from this script
-    LockTime {
-        /// Requested `LockTime`
-        requested: absolute::LockTime,
-        /// Required `LockTime`
-        required: absolute::LockTime,
-    },
-    /// Cannot enable RBF with a `Sequence` >= 0xFFFFFFFE
-    RbfSequence,
-    /// Cannot enable RBF with `Sequence` given a required OP_CSV
-    RbfSequenceCsv {
-        /// Given RBF `Sequence`
-        rbf: Sequence,
-        /// Required OP_CSV `Sequence`
-        csv: Sequence,
-    },
-    /// When bumping a tx the absolute fee requested is lower than replaced tx absolute fee
-    FeeTooLow {
-        /// Required fee absolute value (satoshi)
-        required: u64,
-    },
-    /// When bumping a tx the fee rate requested is lower than required
-    FeeRateTooLow {
-        /// Required fee rate
-        required: bitcoin::FeeRate,
-    },
-    /// `manually_selected_only` option is selected but no utxo has been passed
-    NoUtxosSelected,
-    /// Output created is under the dust limit, 546 satoshis
-    OutputBelowDustLimit(usize),
-    /// The `change_policy` was set but the wallet does not have a change_descriptor
-    ChangePolicyDescriptor,
-    /// There was an error with coin selection
-    CoinSelection(coin_selection::Error),
-    /// Wallet's UTXO set is not enough to cover recipient's requested plus fee
-    InsufficientFunds {
-        /// Sats needed for some transaction
-        needed: u64,
-        /// Sats available for spending
-        available: u64,
-    },
-    /// Cannot build a tx without recipients
-    NoRecipients,
-    /// Partially signed bitcoin transaction error
-    Psbt(psbt::Error),
-    /// In order to use the [`TxBuilder::add_global_xpubs`] option every extended
-    /// key in the descriptor must either be a master key itself (having depth = 0) or have an
-    /// explicit origin provided
-    ///
-    /// [`TxBuilder::add_global_xpubs`]: crate::wallet::tx_builder::TxBuilder::add_global_xpubs
-    MissingKeyOrigin(String),
-    /// Happens when trying to spend an UTXO that is not in the internal database
-    UnknownUtxo,
-    /// Missing non_witness_utxo on foreign utxo for given `OutPoint`
-    MissingNonWitnessUtxo(OutPoint),
-    /// Miniscript PSBT error
-    MiniscriptPsbt(MiniscriptPsbtError),
-}
-
-impl<P> fmt::Display for CreateTxError<P>
-where
-    P: fmt::Display,
-{
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Descriptor(e) => e.fmt(f),
-            Self::Persist(e) => {
-                write!(
-                    f,
-                    "failed to write wallet data to persistence backend: {}",
-                    e
-                )
-            }
-            Self::Policy(e) => e.fmt(f),
-            CreateTxError::SpendingPolicyRequired(keychain_kind) => {
-                write!(f, "Spending policy required: {:?}", keychain_kind)
-            }
-            CreateTxError::Version0 => {
-                write!(f, "Invalid version `0`")
-            }
-            CreateTxError::Version1Csv => {
-                write!(
-                    f,
-                    "TxBuilder requested version `1`, but at least `2` is needed to use OP_CSV"
-                )
-            }
-            CreateTxError::LockTime {
-                requested,
-                required,
-            } => {
-                write!(f, "TxBuilder requested timelock of `{:?}`, but at least `{:?}` is required to spend from this script", required, requested)
-            }
-            CreateTxError::RbfSequence => {
-                write!(f, "Cannot enable RBF with a nSequence >= 0xFFFFFFFE")
-            }
-            CreateTxError::RbfSequenceCsv { rbf, csv } => {
-                write!(
-                    f,
-                    "Cannot enable RBF with nSequence `{:?}` given a required OP_CSV of `{:?}`",
-                    rbf, csv
-                )
-            }
-            CreateTxError::FeeTooLow { required } => {
-                write!(f, "Fee to low: required {} sat", required)
-            }
-            CreateTxError::FeeRateTooLow { required } => {
-                write!(
-                    f,
-                    // Note: alternate fmt as sat/vb (ceil) available in bitcoin-0.31
-                    //"Fee rate too low: required {required:#}"
-                    "Fee rate too low: required {} sat/vb",
-                    crate::floating_rate!(required)
-                )
-            }
-            CreateTxError::NoUtxosSelected => {
-                write!(f, "No UTXO selected")
-            }
-            CreateTxError::OutputBelowDustLimit(limit) => {
-                write!(f, "Output below the dust limit: {}", limit)
-            }
-            CreateTxError::ChangePolicyDescriptor => {
-                write!(
-                    f,
-                    "The `change_policy` can be set only if the wallet has a change_descriptor"
-                )
-            }
-            CreateTxError::CoinSelection(e) => e.fmt(f),
-            CreateTxError::InsufficientFunds { needed, available } => {
-                write!(
-                    f,
-                    "Insufficient funds: {} sat available of {} sat needed",
-                    available, needed
-                )
-            }
-            CreateTxError::NoRecipients => {
-                write!(f, "Cannot build tx without recipients")
-            }
-            CreateTxError::Psbt(e) => e.fmt(f),
-            CreateTxError::MissingKeyOrigin(err) => {
-                write!(f, "Missing key origin: {}", err)
-            }
-            CreateTxError::UnknownUtxo => {
-                write!(f, "UTXO not found in the internal database")
-            }
-            CreateTxError::MissingNonWitnessUtxo(outpoint) => {
-                write!(f, "Missing non_witness_utxo on foreign utxo {}", outpoint)
-            }
-            CreateTxError::MiniscriptPsbt(err) => {
-                write!(f, "Miniscript PSBT error: {}", err)
-            }
-        }
-    }
-}
-
-impl<P> From<descriptor::error::Error> for CreateTxError<P> {
-    fn from(err: descriptor::error::Error) -> Self {
-        CreateTxError::Descriptor(err)
-    }
-}
-
-impl<P> From<PolicyError> for CreateTxError<P> {
-    fn from(err: PolicyError) -> Self {
-        CreateTxError::Policy(err)
-    }
-}
-
-impl<P> From<MiniscriptPsbtError> for CreateTxError<P> {
-    fn from(err: MiniscriptPsbtError) -> Self {
-        CreateTxError::MiniscriptPsbt(err)
-    }
-}
-
-impl<P> From<psbt::Error> for CreateTxError<P> {
-    fn from(err: psbt::Error) -> Self {
-        CreateTxError::Psbt(err)
-    }
-}
-
-impl<P> From<coin_selection::Error> for CreateTxError<P> {
-    fn from(err: coin_selection::Error) -> Self {
-        CreateTxError::CoinSelection(err)
-    }
-}
-
-#[cfg(feature = "std")]
-impl<P: core::fmt::Display + core::fmt::Debug> std::error::Error for CreateTxError<P> {}
-
-#[derive(Debug)]
-/// Error returned from [`Wallet::build_fee_bump`]
-///
-/// [`Wallet::build_fee_bump`]: super::Wallet::build_fee_bump
-pub enum BuildFeeBumpError {
-    /// Happens when trying to spend an UTXO that is not in the internal database
-    UnknownUtxo(OutPoint),
-    /// Thrown when a tx is not found in the internal database
-    TransactionNotFound(Txid),
-    /// Happens when trying to bump a transaction that is already confirmed
-    TransactionConfirmed(Txid),
-    /// Trying to replace a tx that has a sequence >= `0xFFFFFFFE`
-    IrreplaceableTransaction(Txid),
-    /// Node doesn't have data to estimate a fee rate
-    FeeRateUnavailable,
-}
-
-impl fmt::Display for BuildFeeBumpError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::UnknownUtxo(outpoint) => write!(
-                f,
-                "UTXO not found in the internal database with txid: {}, vout: {}",
-                outpoint.txid, outpoint.vout
-            ),
-            Self::TransactionNotFound(txid) => {
-                write!(
-                    f,
-                    "Transaction not found in the internal database with txid: {}",
-                    txid
-                )
-            }
-            Self::TransactionConfirmed(txid) => {
-                write!(f, "Transaction already confirmed with txid: {}", txid)
-            }
-            Self::IrreplaceableTransaction(txid) => {
-                write!(f, "Transaction can't be replaced with txid: {}", txid)
-            }
-            Self::FeeRateUnavailable => write!(f, "Fee rate unavailable"),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for BuildFeeBumpError {}
--- a/crates/bdk/src/wallet/export.rs
+++ b/crates/bdk/src/wallet/export.rs
@@ -56,6 +56,7 @@
 use core::str::FromStr;

 use alloc::string::{String, ToString};
+use bdk_chain::sparse_chain::ChainPosition;
 use serde::{Deserialize, Serialize};

 use miniscript::descriptor::{ShInner, WshInner};
@@ -126,12 +127,11 @@ impl FullyNodedExport {
        Self::is_compatible_with_core(&descriptor)?;

        let blockheight = if include_blockheight {
-            wallet.transactions().next().map_or(0, |canonical_tx| {
-                match canonical_tx.chain_position {
-                    bdk_chain::ChainPosition::Confirmed(a) => a.confirmation_height,
-                    bdk_chain::ChainPosition::Unconfirmed(_) => 0,
-                }
-            })
+            wallet
+                .transactions()
+                .next()
+                .and_then(|(pos, _)| pos.height().into())
+                .unwrap_or(0)
        } else {
            0
        };
@@ -216,7 +216,7 @@ mod test {

    use bdk_chain::{BlockId, ConfirmationTime};
    use bitcoin::hashes::Hash;
-    use bitcoin::{transaction, BlockHash, Network, Transaction};
+    use bitcoin::{BlockHash, Network, Transaction};

    use super::*;
    use crate::wallet::Wallet;
@@ -230,8 +230,8 @@ mod test {
        let transaction = Transaction {
            input: vec![],
            output: vec![],
-            version: transaction::Version::non_standard(0),
-            lock_time: bitcoin::absolute::LockTime::ZERO,
+            version: 0,
+            lock_time: bitcoin::PackedLockTime::ZERO,
        };
        wallet
            .insert_checkpoint(BlockId {
--- a/crates/bdk/src/wallet/hardwaresigner.rs
+++ b/crates/bdk/src/wallet/hardwaresigner.rs
@@ -18,8 +18,8 @@
 //! # use bdk::signer::SignerOrdering;
 //! # use bdk::wallet::hardwaresigner::HWISigner;
 //! # use bdk::wallet::AddressIndex::New;
-//! # use bdk::{KeychainKind, SignOptions, Wallet};
-//! # use hwi::HWIClient;
+//! # use bdk::{FeeRate, KeychainKind, SignOptions, Wallet};
+//! # use hwi::{types::HWIChain, HWIClient};
 //! # use std::sync::Arc;
 //! #
 //! # fn main() -> Result<(), Box<dyn std::error::Error>> {
@@ -28,7 +28,7 @@
 //!     panic!("No devices found!");
 //! }
 //! let first_device = devices.remove(0)?;
-//! let custom_signer = HWISigner::from_device(&first_device, Network::Testnet.into())?;
+//! let custom_signer = HWISigner::from_device(&first_device, HWIChain::Test)?;
 //!
 //! # let mut wallet = Wallet::new_no_persist(
 //! #     "",
@@ -47,9 +47,9 @@
 //! # }
 //! ```

-use bitcoin::bip32::Fingerprint;
+use bitcoin::psbt::PartiallySignedTransaction;
 use bitcoin::secp256k1::{All, Secp256k1};
-use bitcoin::Psbt;
+use bitcoin::util::bip32::Fingerprint;

 use hwi::error::Error;
 use hwi::types::{HWIChain, HWIDevice};
@@ -87,7 +87,7 @@ impl SignerCommon for HWISigner {
 impl TransactionSigner for HWISigner {
    fn sign_transaction(
        &self,
-        psbt: &mut Psbt,
+        psbt: &mut PartiallySignedTransaction,
        _sign_options: &crate::SignOptions,
        _secp: &crate::wallet::utils::SecpCtx,
    ) -> Result<(), SignerError> {
--- a/crates/bdk/src/wallet/mod.rs
+++ b/crates/bdk/src/wallet/mod.rs
--- a/crates/bdk/src/wallet/signer.rs
+++ b/crates/bdk/src/wallet/signer.rs
@@ -19,12 +19,13 @@
 //! # use core::str::FromStr;
 //! # use bitcoin::secp256k1::{Secp256k1, All};
 //! # use bitcoin::*;
+//! # use bitcoin::util::psbt;
 //! # use bdk::signer::*;
 //! # use bdk::*;
 //! # #[derive(Debug)]
 //! # struct CustomHSM;
 //! # impl CustomHSM {
-//! #     fn hsm_sign_input(&self, _psbt: &mut Psbt, _input: usize) -> Result<(), SignerError> {
+//! #     fn hsm_sign_input(&self, _psbt: &mut psbt::PartiallySignedTransaction, _input: usize) -> Result<(), SignerError> {
 //! #         Ok(())
 //! #     }
 //! #     fn connect() -> Self {
@@ -54,7 +55,7 @@
 //! impl InputSigner for CustomSigner {
 //!     fn sign_input(
 //!         &self,
-//!         psbt: &mut Psbt,
+//!         psbt: &mut psbt::PartiallySignedTransaction,
 //!         input_index: usize,
 //!         _sign_options: &SignOptions,
 //!         _secp: &Secp256k1<All>,
@@ -75,35 +76,34 @@
 //!     Arc::new(custom_signer)
 //! );
 //!
-//! # Ok::<_, anyhow::Error>(())
+//! # Ok::<_, bdk::Error>(())
 //! ```

 use crate::collections::BTreeMap;
-use alloc::string::String;
 use alloc::sync::Arc;
 use alloc::vec::Vec;
 use core::cmp::Ordering;
 use core::fmt;
 use core::ops::{Bound::Included, Deref};

-use bitcoin::bip32::{ChildNumber, DerivationPath, Fingerprint, Xpriv};
-use bitcoin::hashes::hash160;
+use bitcoin::blockdata::opcodes;
+use bitcoin::blockdata::script::Builder as ScriptBuilder;
+use bitcoin::hashes::{hash160, Hash};
 use bitcoin::secp256k1::Message;
-use bitcoin::sighash::{EcdsaSighashType, TapSighash, TapSighashType};
-use bitcoin::{ecdsa, psbt, sighash, taproot};
-use bitcoin::{key::TapTweak, key::XOnlyPublicKey, secp256k1};
-use bitcoin::{PrivateKey, Psbt, PublicKey};
+use bitcoin::util::bip32::{ChildNumber, DerivationPath, ExtendedPrivKey, Fingerprint};
+use bitcoin::util::{ecdsa, psbt, schnorr, sighash, taproot};
+use bitcoin::{secp256k1, XOnlyPublicKey};
+use bitcoin::{EcdsaSighashType, PrivateKey, PublicKey, SchnorrSighashType, Script};

 use miniscript::descriptor::{
-    Descriptor, DescriptorMultiXKey, DescriptorPublicKey, DescriptorSecretKey, DescriptorXKey,
-    InnerXKey, KeyMap, SinglePriv, SinglePubKey,
+    Descriptor, DescriptorPublicKey, DescriptorSecretKey, DescriptorXKey, KeyMap, SinglePriv,
+    SinglePubKey,
 };
 use miniscript::{Legacy, Segwitv0, SigType, Tap, ToPublicKey};

 use super::utils::SecpCtx;
 use crate::descriptor::{DescriptorMeta, XKeyUtils};
 use crate::psbt::PsbtUtils;
-use crate::wallet::error::MiniscriptPsbtError;

 /// Identifier of a signer in the `SignersContainers`. Used as a key to find the right signer among
 /// multiple of them
@@ -130,7 +130,7 @@ impl From<Fingerprint> for SignerId {
 }

 /// Signing error
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq, Clone)]
 pub enum SignerError {
    /// The private key is missing for the required public key
    MissingKey,
@@ -160,12 +160,16 @@ pub enum SignerError {
    InvalidSighash,
    /// Error while computing the hash to sign
    SighashError(sighash::Error),
-    /// Miniscript PSBT error
-    MiniscriptPsbt(MiniscriptPsbtError),
-    /// To be used only by external libraries implementing [`InputSigner`] or
-    /// [`TransactionSigner`], so that they can return their own custom errors, without having to
-    /// modify [`SignerError`] in BDK.
-    External(String),
+    /// Error while signing using hardware wallets
+    #[cfg(feature = "hardware-signer")]
+    HWIError(hwi::error::Error),
+}
+
+#[cfg(feature = "hardware-signer")]
+impl From<hwi::error::Error> for SignerError {
+    fn from(e: hwi::error::Error) -> Self {
+        SignerError::HWIError(e)
+    }
 }

 impl From<sighash::Error> for SignerError {
@@ -189,8 +193,8 @@ impl fmt::Display for SignerError {
            Self::NonStandardSighash => write!(f, "The psbt contains a non standard sighash"),
            Self::InvalidSighash => write!(f, "Invalid SIGHASH for the signing context in use"),
            Self::SighashError(err) => write!(f, "Error while computing the hash to sign: {}", err),
-            Self::MiniscriptPsbt(err) => write!(f, "Miniscript PSBT error: {}", err),
-            Self::External(err) => write!(f, "{}", err),
+            #[cfg(feature = "hardware-signer")]
+            Self::HWIError(err) => write!(f, "Error while signing using hardware wallets: {}", err),
        }
    }
 }
@@ -214,7 +218,7 @@ pub enum SignerContext {
    },
 }

-/// Wrapper to pair a signer with its context
+/// Wrapper structure to pair a signer with its context
 #[derive(Debug, Clone)]
 pub struct SignerWrapper<S: Sized + fmt::Debug + Clone> {
    signer: S,
@@ -263,7 +267,7 @@ pub trait InputSigner: SignerCommon {
    /// Sign a single psbt input
    fn sign_input(
        &self,
-        psbt: &mut Psbt,
+        psbt: &mut psbt::PartiallySignedTransaction,
        input_index: usize,
        sign_options: &SignOptions,
        secp: &SecpCtx,
@@ -278,7 +282,7 @@ pub trait TransactionSigner: SignerCommon {
    /// Sign all the inputs of the psbt
    fn sign_transaction(
        &self,
-        psbt: &mut Psbt,
+        psbt: &mut psbt::PartiallySignedTransaction,
        sign_options: &SignOptions,
        secp: &SecpCtx,
    ) -> Result<(), SignerError>;
@@ -287,7 +291,7 @@ pub trait TransactionSigner: SignerCommon {
 impl<T: InputSigner> TransactionSigner for T {
    fn sign_transaction(
        &self,
-        psbt: &mut Psbt,
+        psbt: &mut psbt::PartiallySignedTransaction,
        sign_options: &SignOptions,
        secp: &SecpCtx,
    ) -> Result<(), SignerError> {
@@ -299,7 +303,7 @@ impl<T: InputSigner> TransactionSigner for T {
    }
 }

-impl SignerCommon for SignerWrapper<DescriptorXKey<Xpriv>> {
+impl SignerCommon for SignerWrapper<DescriptorXKey<ExtendedPrivKey>> {
    fn id(&self, secp: &SecpCtx) -> SignerId {
        SignerId::from(self.root_fingerprint(secp))
    }
@@ -309,10 +313,10 @@ impl SignerCommon for SignerWrapper<DescriptorXKey<Xpriv>> {
    }
 }

-impl InputSigner for SignerWrapper<DescriptorXKey<Xpriv>> {
+impl InputSigner for SignerWrapper<DescriptorXKey<ExtendedPrivKey>> {
    fn sign_input(
        &self,
-        psbt: &mut Psbt,
+        psbt: &mut psbt::PartiallySignedTransaction,
        input_index: usize,
        sign_options: &SignOptions,
        secp: &SecpCtx,
@@ -379,48 +383,6 @@ impl InputSigner for SignerWrapper<DescriptorXKey<Xpriv>> {
    }
 }

-fn multikey_to_xkeys<K: InnerXKey + Clone>(
-    multikey: DescriptorMultiXKey<K>,
-) -> Vec<DescriptorXKey<K>> {
-    multikey
-        .derivation_paths
-        .into_paths()
-        .into_iter()
-        .map(|derivation_path| DescriptorXKey {
-            origin: multikey.origin.clone(),
-            xkey: multikey.xkey.clone(),
-            derivation_path,
-            wildcard: multikey.wildcard,
-        })
-        .collect()
-}
-
-impl SignerCommon for SignerWrapper<DescriptorMultiXKey<Xpriv>> {
-    fn id(&self, secp: &SecpCtx) -> SignerId {
-        SignerId::from(self.root_fingerprint(secp))
-    }
-
-    fn descriptor_secret_key(&self) -> Option<DescriptorSecretKey> {
-        Some(DescriptorSecretKey::MultiXPrv(self.signer.clone()))
-    }
-}
-
-impl InputSigner for SignerWrapper<DescriptorMultiXKey<Xpriv>> {
-    fn sign_input(
-        &self,
-        psbt: &mut Psbt,
-        input_index: usize,
-        sign_options: &SignOptions,
-        secp: &SecpCtx,
-    ) -> Result<(), SignerError> {
-        let xkeys = multikey_to_xkeys(self.signer.clone());
-        for xkey in xkeys {
-            SignerWrapper::new(xkey, self.ctx).sign_input(psbt, input_index, sign_options, secp)?
-        }
-        Ok(())
-    }
-}
-
 impl SignerCommon for SignerWrapper<PrivateKey> {
    fn id(&self, secp: &SecpCtx) -> SignerId {
        SignerId::from(self.public_key(secp).to_pubkeyhash(SigType::Ecdsa))
@@ -437,7 +399,7 @@ impl SignerCommon for SignerWrapper<PrivateKey> {
 impl InputSigner for SignerWrapper<PrivateKey> {
    fn sign_input(
        &self,
-        psbt: &mut Psbt,
+        psbt: &mut psbt::PartiallySignedTransaction,
        input_index: usize,
        sign_options: &SignOptions,
        secp: &SecpCtx,
@@ -456,23 +418,20 @@ impl InputSigner for SignerWrapper<PrivateKey> {
        let x_only_pubkey = XOnlyPublicKey::from(pubkey.inner);

        if let SignerContext::Tap { is_internal_key } = self.ctx {
-            if let Some(psbt_internal_key) = psbt.inputs[input_index].tap_internal_key {
-                if is_internal_key
-                    && psbt.inputs[input_index].tap_key_sig.is_none()
-                    && sign_options.sign_with_tap_internal_key
-                    && x_only_pubkey == psbt_internal_key
-                {
-                    let (hash, hash_ty) = Tap::sighash(psbt, input_index, None)?;
-                    sign_psbt_schnorr(
-                        &self.inner,
-                        x_only_pubkey,
-                        None,
-                        &mut psbt.inputs[input_index],
-                        hash,
-                        hash_ty,
-                        secp,
-                    );
-                }
+            if is_internal_key
+                && psbt.inputs[input_index].tap_key_sig.is_none()
+                && sign_options.sign_with_tap_internal_key
+            {
+                let (hash, hash_ty) = Tap::sighash(psbt, input_index, None)?;
+                sign_psbt_schnorr(
+                    &self.inner,
+                    x_only_pubkey,
+                    None,
+                    &mut psbt.inputs[input_index],
+                    hash,
+                    hash_ty,
+                    secp,
+                );
            }

            if let Some((leaf_hashes, _)) =
@@ -518,16 +477,8 @@ impl InputSigner for SignerWrapper<PrivateKey> {
        }

        let (hash, hash_ty) = match self.ctx {
-            SignerContext::Segwitv0 => {
-                let (h, t) = Segwitv0::sighash(psbt, input_index, ())?;
-                let h = h.to_raw_hash();
-                (h, t)
-            }
-            SignerContext::Legacy => {
-                let (h, t) = Legacy::sighash(psbt, input_index, ())?;
-                let h = h.to_raw_hash();
-                (h, t)
-            }
+            SignerContext::Segwitv0 => Segwitv0::sighash(psbt, input_index, ())?,
+            SignerContext::Legacy => Legacy::sighash(psbt, input_index, ())?,
            _ => return Ok(()), // handled above
        };
        sign_psbt_ecdsa(
@@ -548,12 +499,12 @@ fn sign_psbt_ecdsa(
    secret_key: &secp256k1::SecretKey,
    pubkey: PublicKey,
    psbt_input: &mut psbt::Input,
-    hash: impl bitcoin::hashes::Hash + bitcoin::secp256k1::ThirtyTwoByteHash,
+    hash: bitcoin::Sighash,
    hash_ty: EcdsaSighashType,
    secp: &SecpCtx,
    allow_grinding: bool,
 ) {
-    let msg = &Message::from(hash);
+    let msg = &Message::from_slice(&hash.into_inner()[..]).unwrap();
    let sig = if allow_grinding {
        secp.sign_ecdsa_low_r(msg, secret_key)
    } else {
@@ -562,7 +513,7 @@ fn sign_psbt_ecdsa(
    secp.verify_ecdsa(msg, &sig, &pubkey.inner)
        .expect("invalid or corrupted ecdsa signature");

-    let final_signature = ecdsa::Signature { sig, hash_ty };
+    let final_signature = ecdsa::EcdsaSig { sig, hash_ty };
    psbt_input.partial_sigs.insert(pubkey, final_signature);
 }

@@ -572,11 +523,13 @@ fn sign_psbt_schnorr(
    pubkey: XOnlyPublicKey,
    leaf_hash: Option<taproot::TapLeafHash>,
    psbt_input: &mut psbt::Input,
-    hash: TapSighash,
-    hash_ty: TapSighashType,
+    hash: taproot::TapSighashHash,
+    hash_ty: SchnorrSighashType,
    secp: &SecpCtx,
 ) {
-    let keypair = secp256k1::Keypair::from_seckey_slice(secp, secret_key.as_ref()).unwrap();
+    use schnorr::TapTweak;
+
+    let keypair = secp256k1::KeyPair::from_seckey_slice(secp, secret_key.as_ref()).unwrap();
    let keypair = match leaf_hash {
        None => keypair
            .tap_tweak(secp, psbt_input.tap_merkle_root)
@@ -584,12 +537,12 @@ fn sign_psbt_schnorr(
        Some(_) => keypair, // no tweak for script spend
    };

-    let msg = &Message::from(hash);
+    let msg = &Message::from_slice(&hash.into_inner()[..]).unwrap();
    let sig = secp.sign_schnorr(msg, &keypair);
    secp.verify_schnorr(&sig, msg, &XOnlyPublicKey::from_keypair(&keypair).0)
        .expect("invalid or corrupted schnorr signature");

-    let final_signature = taproot::Signature { sig, hash_ty };
+    let final_signature = schnorr::SchnorrSig { sig, hash_ty };

    if let Some(lh) = leaf_hash {
        psbt_input
@@ -679,11 +632,6 @@ impl SignersContainer {
                    SignerOrdering::default(),
                    Arc::new(SignerWrapper::new(xprv, ctx)),
                ),
-                DescriptorSecretKey::MultiXPrv(xprv) => container.add_external(
-                    SignerId::from(xprv.root_fingerprint(secp)),
-                    SignerOrdering::default(),
-                    Arc::new(SignerWrapper::new(xprv, ctx)),
-                ),
            };
        }

@@ -751,7 +699,7 @@ pub struct SignOptions {
    /// Whether the signer should trust the `witness_utxo`, if the `non_witness_utxo` hasn't been
    /// provided
    ///
-    /// Defaults to `false` to mitigate the "SegWit bug" which should trick the wallet into
+    /// Defaults to `false` to mitigate the "SegWit bug" which chould trick the wallet into
    /// paying a fee larger than expected.
    ///
    /// Some wallets, especially if relatively old, might not provide the `non_witness_utxo` for
@@ -781,16 +729,6 @@ pub struct SignOptions {
    /// Defaults to `true` which will remove partial signatures during finalization.
    pub remove_partial_sigs: bool,

-    /// Whether to remove taproot specific fields from the PSBT on finalization.
-    ///
-    /// For inputs this includes the taproot internal key, merkle root, and individual
-    /// scripts and signatures. For both inputs and outputs it includes key origin info.
-    ///
-    /// Defaults to `true` which will remove all of the above mentioned fields when finalizing.
-    ///
-    /// See [`BIP371`](https://github.com/bitcoin/bips/blob/master/bip-0371.mediawiki) for details.
-    pub remove_taproot_extras: bool,
-
    /// Whether to try finalizing the PSBT after the inputs are signed.
    ///
    /// Defaults to `true` which will try finalizing PSBT after inputs are signed.
@@ -815,10 +753,9 @@ pub struct SignOptions {
 }

 /// Customize which taproot script-path leaves the signer should sign.
-#[derive(Default, Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum TapLeavesOptions {
    /// The signer will sign all the leaves it has a key for.
-    #[default]
    All,
    /// The signer won't sign leaves other than the ones specified. Note that it could still ignore
    /// some of the specified leaves, if it doesn't have the right key to sign them.
@@ -829,6 +766,13 @@ pub enum TapLeavesOptions {
    None,
 }

+impl Default for TapLeavesOptions {
+    fn default() -> Self {
+        TapLeavesOptions::All
+    }
+}
+
+#[allow(clippy::derivable_impls)]
 impl Default for SignOptions {
    fn default() -> Self {
        SignOptions {
@@ -836,7 +780,6 @@ impl Default for SignOptions {
            assume_height: None,
            allow_all_sighashes: false,
            remove_partial_sigs: true,
-            remove_taproot_extras: true,
            try_finalize: true,
            tap_leaves_options: TapLeavesOptions::default(),
            sign_with_tap_internal_key: true,
@@ -851,7 +794,7 @@ pub(crate) trait ComputeSighash {
    type SighashType;

    fn sighash(
-        psbt: &Psbt,
+        psbt: &psbt::PartiallySignedTransaction,
        input_index: usize,
        extra: Self::Extra,
    ) -> Result<(Self::Sighash, Self::SighashType), SignerError>;
@@ -859,11 +802,11 @@ pub(crate) trait ComputeSighash {

 impl ComputeSighash for Legacy {
    type Extra = ();
-    type Sighash = sighash::LegacySighash;
+    type Sighash = bitcoin::Sighash;
    type SighashType = EcdsaSighashType;

    fn sighash(
-        psbt: &Psbt,
+        psbt: &psbt::PartiallySignedTransaction,
        input_index: usize,
        _extra: (),
    ) -> Result<(Self::Sighash, Self::SighashType), SignerError> {
@@ -906,13 +849,23 @@ impl ComputeSighash for Legacy {
    }
 }

+fn p2wpkh_script_code(script: &Script) -> Script {
+    ScriptBuilder::new()
+        .push_opcode(opcodes::all::OP_DUP)
+        .push_opcode(opcodes::all::OP_HASH160)
+        .push_slice(&script[2..])
+        .push_opcode(opcodes::all::OP_EQUALVERIFY)
+        .push_opcode(opcodes::all::OP_CHECKSIG)
+        .into_script()
+}
+
 impl ComputeSighash for Segwitv0 {
    type Extra = ();
-    type Sighash = sighash::SegwitV0Sighash;
+    type Sighash = bitcoin::Sighash;
    type SighashType = EcdsaSighashType;

    fn sighash(
-        psbt: &Psbt,
+        psbt: &psbt::PartiallySignedTransaction,
        input_index: usize,
        _extra: (),
    ) -> Result<(Self::Sighash, Self::SighashType), SignerError> {
@@ -923,7 +876,7 @@ impl ComputeSighash for Segwitv0 {
        let psbt_input = &psbt.inputs[input_index];
        let tx_input = &psbt.unsigned_tx.input[input_index];

-        let sighash_type = psbt_input
+        let sighash = psbt_input
            .sighash_type
            .unwrap_or_else(|| EcdsaSighashType::All.into())
            .ecdsa_hash_ty()
@@ -951,52 +904,46 @@ impl ComputeSighash for Segwitv0 {
        };
        let value = utxo.value;

-        let mut sighasher = sighash::SighashCache::new(&psbt.unsigned_tx);
-
-        let sighash = match psbt_input.witness_script {
-            Some(ref witness_script) => {
-                sighasher.p2wsh_signature_hash(input_index, witness_script, value, sighash_type)?
-            }
+        let script = match psbt_input.witness_script {
+            Some(ref witness_script) => witness_script.clone(),
            None => {
-                if utxo.script_pubkey.is_p2wpkh() {
-                    sighasher.p2wpkh_signature_hash(
-                        input_index,
-                        &utxo.script_pubkey,
-                        value,
-                        sighash_type,
-                    )?
+                if utxo.script_pubkey.is_v0_p2wpkh() {
+                    p2wpkh_script_code(&utxo.script_pubkey)
                } else if psbt_input
                    .redeem_script
                    .as_ref()
-                    .map(|s| s.is_p2wpkh())
+                    .map(Script::is_v0_p2wpkh)
                    .unwrap_or(false)
                {
-                    let script_pubkey = psbt_input.redeem_script.as_ref().unwrap();
-                    sighasher.p2wpkh_signature_hash(
-                        input_index,
-                        script_pubkey,
-                        value,
-                        sighash_type,
-                    )?
+                    p2wpkh_script_code(psbt_input.redeem_script.as_ref().unwrap())
                } else {
                    return Err(SignerError::MissingWitnessScript);
                }
            }
        };
-        Ok((sighash, sighash_type))
+
+        Ok((
+            sighash::SighashCache::new(&psbt.unsigned_tx).segwit_signature_hash(
+                input_index,
+                &script,
+                value,
+                sighash,
+            )?,
+            sighash,
+        ))
    }
 }

 impl ComputeSighash for Tap {
    type Extra = Option<taproot::TapLeafHash>;
-    type Sighash = TapSighash;
-    type SighashType = TapSighashType;
+    type Sighash = taproot::TapSighashHash;
+    type SighashType = SchnorrSighashType;

    fn sighash(
-        psbt: &Psbt,
+        psbt: &psbt::PartiallySignedTransaction,
        input_index: usize,
        extra: Self::Extra,
-    ) -> Result<(Self::Sighash, TapSighashType), SignerError> {
+    ) -> Result<(Self::Sighash, SchnorrSighashType), SignerError> {
        if input_index >= psbt.inputs.len() || input_index >= psbt.unsigned_tx.input.len() {
            return Err(SignerError::InputIndexOutOfRange);
        }
@@ -1005,8 +952,8 @@ impl ComputeSighash for Tap {

        let sighash_type = psbt_input
            .sighash_type
-            .unwrap_or_else(|| TapSighashType::Default.into())
-            .taproot_hash_ty()
+            .unwrap_or_else(|| SchnorrSighashType::Default.into())
+            .schnorr_hash_ty()
            .map_err(|_| SignerError::InvalidSighash)?;
        let witness_utxos = (0..psbt.inputs.len())
            .map(|i| psbt.get_utxo_for(i))
@@ -1068,8 +1015,8 @@ mod signers_container_tests {
    use crate::descriptor::IntoWalletDescriptor;
    use crate::keys::{DescriptorKey, IntoDescriptorKey};
    use assert_matches::assert_matches;
-    use bitcoin::bip32;
    use bitcoin::secp256k1::{All, Secp256k1};
+    use bitcoin::util::bip32;
    use bitcoin::Network;
    use core::str::FromStr;
    use miniscript::ScriptContext;
@@ -1164,7 +1111,7 @@ mod signers_container_tests {
    impl TransactionSigner for DummySigner {
        fn sign_transaction(
            &self,
-            _psbt: &mut Psbt,
+            _psbt: &mut psbt::PartiallySignedTransaction,
            _sign_options: &SignOptions,
            _secp: &SecpCtx,
        ) -> Result<(), SignerError> {
@@ -1182,8 +1129,8 @@ mod signers_container_tests {
    ) -> (DescriptorKey<Ctx>, DescriptorKey<Ctx>, Fingerprint) {
        let secp: Secp256k1<All> = Secp256k1::new();
        let path = bip32::DerivationPath::from_str(PATH).unwrap();
-        let tprv = bip32::Xpriv::from_str(tprv).unwrap();
-        let tpub = bip32::Xpub::from_priv(&secp, &tprv);
+        let tprv = bip32::ExtendedPrivKey::from_str(tprv).unwrap();
+        let tpub = bip32::ExtendedPubKey::from_priv(&secp, &tprv);
        let fingerprint = tprv.fingerprint(&secp);
        let prvkey = (tprv, path.clone()).into_descriptor_key().unwrap();
        let pubkey = (tpub, path).into_descriptor_key().unwrap();
--- a/crates/bdk/src/wallet/tx_builder.rs
+++ b/crates/bdk/src/wallet/tx_builder.rs
@@ -17,12 +17,8 @@
 //! # use std::str::FromStr;
 //! # use bitcoin::*;
 //! # use bdk::*;
-//! # use bdk::wallet::ChangeSet;
-//! # use bdk::wallet::error::CreateTxError;
 //! # use bdk::wallet::tx_builder::CreateTx;
-//! # use bdk_chain::PersistBackend;
-//! # use anyhow::Error;
-//! # let to_address = Address::from_str("2N4eQYCbKUHCCTUjBJeHcJp9ok6J2GZsTDt").unwrap().assume_checked();
+//! # let to_address = Address::from_str("2N4eQYCbKUHCCTUjBJeHcJp9ok6J2GZsTDt").unwrap();
 //! # let mut wallet = doctest_wallet!();
 //! // create a TxBuilder from a wallet
 //! let mut tx_builder = wallet.build_tx();
@@ -31,30 +27,32 @@
 //!     // Create a transaction with one output to `to_address` of 50_000 satoshi
 //!     .add_recipient(to_address.script_pubkey(), 50_000)
 //!     // With a custom fee rate of 5.0 satoshi/vbyte
-//!     .fee_rate(FeeRate::from_sat_per_vb(5).expect("valid feerate"))
+//!     .fee_rate(FeeRate::from_sat_per_vb(5.0))
 //!     // Only spend non-change outputs
 //!     .do_not_spend_change()
 //!     // Turn on RBF signaling
 //!     .enable_rbf();
-//! let psbt = tx_builder.finish()?;
-//! # Ok::<(), anyhow::Error>(())
+//! let (psbt, tx_details) = tx_builder.finish()?;
+//! # Ok::<(), bdk::Error>(())
 //! ```

+use crate::collections::BTreeMap;
+use crate::collections::HashSet;
 use alloc::{boxed::Box, rc::Rc, string::String, vec::Vec};
+use bdk_chain::ConfirmationTime;
 use core::cell::RefCell;
-use core::fmt;
 use core::marker::PhantomData;

-use bdk_chain::PersistBackend;
-use bitcoin::psbt::{self, Psbt};
-use bitcoin::script::PushBytes;
-use bitcoin::{absolute, FeeRate, OutPoint, ScriptBuf, Sequence, Transaction, Txid};
+use bitcoin::util::psbt::{self, PartiallySignedTransaction as Psbt};
+use bitcoin::{LockTime, OutPoint, Script, Sequence, Transaction};

 use super::coin_selection::{CoinSelectionAlgorithm, DefaultCoinSelectionAlgorithm};
-use super::{ChangeSet, CreateTxError, Wallet};
-use crate::collections::{BTreeMap, HashSet};
-use crate::{KeychainKind, LocalOutput, Utxo, WeightedUtxo};
-
+use super::persist;
+use crate::{
+    types::{FeeRate, KeychainKind, LocalUtxo, WeightedUtxo},
+    TransactionDetails,
+};
+use crate::{Error, Utxo, Wallet};
 /// Context in which the [`TxBuilder`] is valid
 pub trait TxBuilderContext: core::fmt::Debug + Default + Clone {}

@@ -83,15 +81,11 @@ impl TxBuilderContext for BumpFee {}
 /// # use bdk::wallet::tx_builder::*;
 /// # use bitcoin::*;
 /// # use core::str::FromStr;
-/// # use bdk::wallet::ChangeSet;
-/// # use bdk::wallet::error::CreateTxError;
-/// # use bdk_chain::PersistBackend;
-/// # use anyhow::Error;
 /// # let mut wallet = doctest_wallet!();
-/// # let addr1 = Address::from_str("2N4eQYCbKUHCCTUjBJeHcJp9ok6J2GZsTDt").unwrap().assume_checked();
+/// # let addr1 = Address::from_str("2N4eQYCbKUHCCTUjBJeHcJp9ok6J2GZsTDt").unwrap();
 /// # let addr2 = addr1.clone();
 /// // chaining
-/// let psbt1 = {
+/// let (psbt1, details) = {
 ///     let mut builder = wallet.build_tx();
 ///     builder
 ///         .ordering(TxOrdering::Untouched)
@@ -101,7 +95,7 @@ impl TxBuilderContext for BumpFee {}
 /// };
 ///
 /// // non-chaining
-/// let psbt2 = {
+/// let (psbt2, details) = {
 ///     let mut builder = wallet.build_tx();
 ///     builder.ordering(TxOrdering::Untouched);
 ///     for addr in &[addr1, addr2] {
@@ -111,7 +105,7 @@ impl TxBuilderContext for BumpFee {}
 /// };
 ///
 /// assert_eq!(psbt1.unsigned_tx.output[..2], psbt2.unsigned_tx.output[..2]);
-/// # Ok::<(), anyhow::Error>(())
+/// # Ok::<(), bdk::Error>(())
 /// ```
 ///
 /// At the moment [`coin_selection`] is an exception to the rule as it consumes `self`.
@@ -135,9 +129,9 @@ pub struct TxBuilder<'a, D, Cs, Ctx> {
 //TODO: TxParams should eventually be exposed publicly.
 #[derive(Default, Debug, Clone)]
 pub(crate) struct TxParams {
-    pub(crate) recipients: Vec<(ScriptBuf, u64)>,
+    pub(crate) recipients: Vec<(Script, u64)>,
    pub(crate) drain_wallet: bool,
-    pub(crate) drain_to: Option<ScriptBuf>,
+    pub(crate) drain_to: Option<Script>,
    pub(crate) fee_policy: Option<FeePolicy>,
    pub(crate) internal_policy_path: Option<BTreeMap<String, Vec<usize>>>,
    pub(crate) external_policy_path: Option<BTreeMap<String, Vec<usize>>>,
@@ -146,7 +140,7 @@ pub(crate) struct TxParams {
    pub(crate) manually_selected_only: bool,
    pub(crate) sighash: Option<psbt::PsbtSighashType>,
    pub(crate) ordering: TxOrdering,
-    pub(crate) locktime: Option<absolute::LockTime>,
+    pub(crate) locktime: Option<LockTime>,
    pub(crate) rbf: Option<RbfValue>,
    pub(crate) version: Option<Version>,
    pub(crate) change_policy: ChangeSpendPolicy,
@@ -154,14 +148,14 @@ pub(crate) struct TxParams {
    pub(crate) add_global_xpubs: bool,
    pub(crate) include_output_redeem_witness_script: bool,
    pub(crate) bumping_fee: Option<PreviousFee>,
-    pub(crate) current_height: Option<absolute::LockTime>,
+    pub(crate) current_height: Option<LockTime>,
    pub(crate) allow_dust: bool,
 }

 #[derive(Clone, Copy, Debug)]
 pub(crate) struct PreviousFee {
    pub absolute: u64,
-    pub rate: FeeRate,
+    pub rate: f32,
 }

 #[derive(Debug, Clone, Copy)]
@@ -172,7 +166,7 @@ pub(crate) enum FeePolicy {

 impl Default for FeePolicy {
    fn default() -> Self {
-        FeePolicy::FeeRate(FeeRate::BROADCAST_MIN)
+        FeePolicy::FeeRate(FeeRate::default_min_relay_fee())
    }
 }

@@ -188,31 +182,14 @@ impl<'a, D, Cs: Clone, Ctx> Clone for TxBuilder<'a, D, Cs, Ctx> {
 }

 // methods supported by both contexts, for any CoinSelectionAlgorithm
-impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
-    /// Set a custom fee rate.
-    ///
-    /// This method sets the mining fee paid by the transaction as a rate on its size.
-    /// This means that the total fee paid is equal to `fee_rate` times the size
-    /// of the transaction. Default is 1 sat/vB in accordance with Bitcoin Core's default
-    /// relay policy.
-    ///
-    /// Note that this is really a minimum feerate -- it's possible to
-    /// overshoot it slightly since adding a change output to drain the remaining
-    /// excess might not be viable.
+impl<'a, D, Cs: CoinSelectionAlgorithm, Ctx: TxBuilderContext> TxBuilder<'a, D, Cs, Ctx> {
+    /// Set a custom fee rate
    pub fn fee_rate(&mut self, fee_rate: FeeRate) -> &mut Self {
        self.params.fee_policy = Some(FeePolicy::FeeRate(fee_rate));
        self
    }

    /// Set an absolute fee
-    /// The fee_absolute method refers to the absolute transaction fee in satoshis (sats).
-    /// If anyone sets both the fee_absolute method and the fee_rate method,
-    /// the FeePolicy enum will be set by whichever method was called last,
-    /// as the FeeRate and FeeAmount are mutually exclusive.
-    ///
-    /// Note that this is really a minimum absolute fee -- it's possible to
-    /// overshoot it slightly since adding a change output to drain the remaining
-    /// excess might not be viable.
    pub fn fee_absolute(&mut self, fee_amount: u64) -> &mut Self {
        self.params.fee_policy = Some(FeePolicy::FeeAmount(fee_amount));
        self
@@ -265,10 +242,7 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
    /// # use std::collections::BTreeMap;
    /// # use bitcoin::*;
    /// # use bdk::*;
-    /// # let to_address =
-    /// Address::from_str("2N4eQYCbKUHCCTUjBJeHcJp9ok6J2GZsTDt")
-    ///     .unwrap()
-    ///     .assume_checked();
+    /// # let to_address = Address::from_str("2N4eQYCbKUHCCTUjBJeHcJp9ok6J2GZsTDt").unwrap();
    /// # let mut wallet = doctest_wallet!();
    /// let mut path = BTreeMap::new();
    /// path.insert("aabbccdd".to_string(), vec![0, 1]);
@@ -278,7 +252,7 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
    ///     .add_recipient(to_address.script_pubkey(), 50_000)
    ///     .policy_path(path, KeychainKind::External);
    ///
-    /// # Ok::<(), anyhow::Error>(())
+    /// # Ok::<(), bdk::Error>(())
    /// ```
    pub fn policy_path(
        &mut self,
@@ -300,21 +274,17 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
    ///
    /// These have priority over the "unspendable" utxos, meaning that if a utxo is present both in
    /// the "utxos" and the "unspendable" list, it will be spent.
-    pub fn add_utxos(&mut self, outpoints: &[OutPoint]) -> Result<&mut Self, AddUtxoError> {
+    pub fn add_utxos(&mut self, outpoints: &[OutPoint]) -> Result<&mut Self, Error> {
        {
            let wallet = self.wallet.borrow();
            let utxos = outpoints
                .iter()
-                .map(|outpoint| {
-                    wallet
-                        .get_utxo(*outpoint)
-                        .ok_or(AddUtxoError::UnknownUtxo(*outpoint))
-                })
+                .map(|outpoint| wallet.get_utxo(*outpoint).ok_or(Error::UnknownUtxo))
                .collect::<Result<Vec<_>, _>>()?;

            for utxo in utxos {
                let descriptor = wallet.get_descriptor_for_keychain(utxo.keychain);
-                let satisfaction_weight = descriptor.max_weight_to_satisfy().unwrap();
+                let satisfaction_weight = descriptor.max_satisfaction_weight().unwrap();
                self.params.utxos.push(WeightedUtxo {
                    satisfaction_weight,
                    utxo: Utxo::Local(utxo),
@@ -329,7 +299,7 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
    ///
    /// These have priority over the "unspendable" utxos, meaning that if a utxo is present both in
    /// the "utxos" and the "unspendable" list, it will be spent.
-    pub fn add_utxo(&mut self, outpoint: OutPoint) -> Result<&mut Self, AddUtxoError> {
+    pub fn add_utxo(&mut self, outpoint: OutPoint) -> Result<&mut Self, Error> {
        self.add_utxos(&[outpoint])
    }

@@ -355,16 +325,12 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
    /// causing you to pay a fee that is too high. The party who is broadcasting the transaction can
    /// of course check the real input weight matches the expected weight prior to broadcasting.
    ///
-    /// To guarantee the `max_weight_to_satisfy` is correct, you can require the party providing the
+    /// To guarantee the `satisfaction_weight` is correct, you can require the party providing the
    /// `psbt_input` provide a miniscript descriptor for the input so you can check it against the
-    /// `script_pubkey` and then ask it for the [`max_weight_to_satisfy`].
+    /// `script_pubkey` and then ask it for the [`max_satisfaction_weight`].
    ///
    /// This is an **EXPERIMENTAL** feature, API and other major changes are expected.
    ///
-    /// In order to use [`Wallet::calculate_fee`] or [`Wallet::calculate_fee_rate`] for a transaction
-    /// created with foreign UTXO(s) you must manually insert the corresponding TxOut(s) into the tx
-    /// graph using the [`Wallet::insert_txout`] function.
-    ///
    /// # Errors
    ///
    /// This method returns errors in the following circumstances:
@@ -378,44 +344,29 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
    ///
    /// [`only_witness_utxo`]: Self::only_witness_utxo
    /// [`finish`]: Self::finish
-    /// [`max_weight_to_satisfy`]: miniscript::Descriptor::max_weight_to_satisfy
+    /// [`max_satisfaction_weight`]: miniscript::Descriptor::max_satisfaction_weight
    pub fn add_foreign_utxo(
        &mut self,
        outpoint: OutPoint,
        psbt_input: psbt::Input,
        satisfaction_weight: usize,
-    ) -> Result<&mut Self, AddForeignUtxoError> {
-        self.add_foreign_utxo_with_sequence(
-            outpoint,
-            psbt_input,
-            satisfaction_weight,
-            Sequence::MAX,
-        )
-    }
-
-    /// Same as [add_foreign_utxo](TxBuilder::add_foreign_utxo) but allows to set the nSequence value.
-    pub fn add_foreign_utxo_with_sequence(
-        &mut self,
-        outpoint: OutPoint,
-        psbt_input: psbt::Input,
-        satisfaction_weight: usize,
-        sequence: Sequence,
-    ) -> Result<&mut Self, AddForeignUtxoError> {
+    ) -> Result<&mut Self, Error> {
        if psbt_input.witness_utxo.is_none() {
            match psbt_input.non_witness_utxo.as_ref() {
                Some(tx) => {
                    if tx.txid() != outpoint.txid {
-                        return Err(AddForeignUtxoError::InvalidTxid {
-                            input_txid: tx.txid(),
-                            foreign_utxo: outpoint,
-                        });
+                        return Err(Error::Generic(
+                            "Foreign utxo outpoint does not match PSBT input".into(),
+                        ));
                    }
                    if tx.output.len() <= outpoint.vout as usize {
-                        return Err(AddForeignUtxoError::InvalidOutpoint(outpoint));
+                        return Err(Error::InvalidOutpoint(outpoint));
                    }
                }
                None => {
-                    return Err(AddForeignUtxoError::MissingUtxo);
+                    return Err(Error::Generic(
+                        "Foreign utxo missing witness_utxo or non_witness_utxo".into(),
+                    ))
                }
            }
        }
@@ -424,7 +375,6 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
            satisfaction_weight,
            utxo: Utxo::Foreign {
                outpoint,
-                sequence: Some(sequence),
                psbt_input: Box::new(psbt_input),
            },
        });
@@ -478,7 +428,7 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
    /// Use a specific nLockTime while creating the transaction
    ///
    /// This can cause conflicts if the wallet's descriptors contain an "after" (OP_CLTV) operator.
-    pub fn nlocktime(&mut self, locktime: absolute::LockTime) -> &mut Self {
+    pub fn nlocktime(&mut self, locktime: LockTime) -> &mut Self {
        self.params.locktime = Some(locktime);
        self
    }
@@ -517,7 +467,7 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
        self
    }

-    /// Only Fill-in the [`psbt::Input::witness_utxo`](bitcoin::psbt::Input::witness_utxo) field when spending from
+    /// Only Fill-in the [`psbt::Input::witness_utxo`](bitcoin::util::psbt::Input::witness_utxo) field when spending from
    /// SegWit descriptors.
    ///
    /// This reduces the size of the PSBT, but some signers might reject them due to the lack of
@@ -527,8 +477,8 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
        self
    }

-    /// Fill-in the [`psbt::Output::redeem_script`](bitcoin::psbt::Output::redeem_script) and
-    /// [`psbt::Output::witness_script`](bitcoin::psbt::Output::witness_script) fields.
+    /// Fill-in the [`psbt::Output::redeem_script`](bitcoin::util::psbt::Output::redeem_script) and
+    /// [`psbt::Output::witness_script`](bitcoin::util::psbt::Output::witness_script) fields.
    ///
    /// This is useful for signers which always require it, like ColdCard hardware wallets.
    pub fn include_output_redeem_witness_script(&mut self) -> &mut Self {
@@ -554,7 +504,7 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {

    /// Choose the coin selection algorithm
    ///
-    /// Overrides the [`DefaultCoinSelectionAlgorithm`].
+    /// Overrides the [`DefaultCoinSelectionAlgorithm`](super::coin_selection::DefaultCoinSelectionAlgorithm).
    ///
    /// Note that this function consumes the builder and returns it so it is usually best to put this as the first call on the builder.
    pub fn coin_selection<P: CoinSelectionAlgorithm>(
@@ -569,6 +519,20 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
        }
    }

+    /// Finish building the transaction.
+    ///
+    /// Returns the [`BIP174`] "PSBT" and summary details about the transaction.
+    ///
+    /// [`BIP174`]: https://github.com/bitcoin/bips/blob/master/bip-0174.mediawiki
+    pub fn finish(self) -> Result<(Psbt, TransactionDetails), Error>
+    where
+        D: persist::PersistBackend<KeychainKind, ConfirmationTime>,
+    {
+        self.wallet
+            .borrow_mut()
+            .create_tx(self.coin_selection, self.params)
+    }
+
    /// Enable signaling RBF
    ///
    /// This will use the default nSequence value of `0xFFFFFFFD`.
@@ -601,8 +565,7 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
    ///
    /// In both cases, if you don't provide a current height, we use the last sync height.
    pub fn current_height(&mut self, height: u32) -> &mut Self {
-        self.params.current_height =
-            Some(absolute::LockTime::from_height(height).expect("Invalid height"));
+        self.params.current_height = Some(LockTime::from_height(height).expect("Invalid height"));
        self
    }

@@ -615,122 +578,22 @@ impl<'a, D, Cs, Ctx> TxBuilder<'a, D, Cs, Ctx> {
    }
 }

-impl<'a, D, Cs: CoinSelectionAlgorithm, Ctx> TxBuilder<'a, D, Cs, Ctx> {
-    /// Finish building the transaction.
-    ///
-    /// Returns a new [`Psbt`] per [`BIP174`].
-    ///
-    /// [`BIP174`]: https://github.com/bitcoin/bips/blob/master/bip-0174.mediawiki
-    pub fn finish(self) -> Result<Psbt, CreateTxError<D::WriteError>>
-    where
-        D: PersistBackend<ChangeSet>,
-    {
-        self.wallet
-            .borrow_mut()
-            .create_tx(self.coin_selection, self.params)
-    }
-}
-
-#[derive(Debug)]
-/// Error returned from [`TxBuilder::add_utxo`] and [`TxBuilder::add_utxos`]
-pub enum AddUtxoError {
-    /// Happens when trying to spend an UTXO that is not in the internal database
-    UnknownUtxo(OutPoint),
-}
-
-impl fmt::Display for AddUtxoError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::UnknownUtxo(outpoint) => write!(
-                f,
-                "UTXO not found in the internal database for txid: {} with vout: {}",
-                outpoint.txid, outpoint.vout
-            ),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for AddUtxoError {}
-
-#[derive(Debug)]
-/// Error returned from [`TxBuilder::add_foreign_utxo`].
-pub enum AddForeignUtxoError {
-    /// Foreign utxo outpoint txid does not match PSBT input txid
-    InvalidTxid {
-        /// PSBT input txid
-        input_txid: Txid,
-        /// Foreign UTXO outpoint
-        foreign_utxo: OutPoint,
-    },
-    /// Requested outpoint doesn't exist in the tx (vout greater than available outputs)
-    InvalidOutpoint(OutPoint),
-    /// Foreign utxo missing witness_utxo or non_witness_utxo
-    MissingUtxo,
-}
-
-impl fmt::Display for AddForeignUtxoError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::InvalidTxid {
-                input_txid,
-                foreign_utxo,
-            } => write!(
-                f,
-                "Foreign UTXO outpoint txid: {} does not match PSBT input txid: {}",
-                foreign_utxo.txid, input_txid,
-            ),
-            Self::InvalidOutpoint(outpoint) => write!(
-                f,
-                "Requested outpoint doesn't exist for txid: {} with vout: {}",
-                outpoint.txid, outpoint.vout,
-            ),
-            Self::MissingUtxo => write!(f, "Foreign utxo missing witness_utxo or non_witness_utxo"),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for AddForeignUtxoError {}
-
-#[derive(Debug)]
-/// Error returned from [`TxBuilder::allow_shrinking`]
-pub enum AllowShrinkingError {
-    /// Script/PubKey was not in the original transaction
-    MissingScriptPubKey(ScriptBuf),
-}
-
-impl fmt::Display for AllowShrinkingError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::MissingScriptPubKey(script_buf) => write!(
-                f,
-                "Script/PubKey was not in the original transaction: {}",
-                script_buf,
-            ),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for AllowShrinkingError {}
-
 impl<'a, D, Cs: CoinSelectionAlgorithm> TxBuilder<'a, D, Cs, CreateTx> {
    /// Replace the recipients already added with a new list
-    pub fn set_recipients(&mut self, recipients: Vec<(ScriptBuf, u64)>) -> &mut Self {
+    pub fn set_recipients(&mut self, recipients: Vec<(Script, u64)>) -> &mut Self {
        self.params.recipients = recipients;
        self
    }

    /// Add a recipient to the internal list
-    pub fn add_recipient(&mut self, script_pubkey: ScriptBuf, amount: u64) -> &mut Self {
+    pub fn add_recipient(&mut self, script_pubkey: Script, amount: u64) -> &mut Self {
        self.params.recipients.push((script_pubkey, amount));
        self
    }

    /// Add data as an output, using OP_RETURN
-    pub fn add_data<T: AsRef<PushBytes>>(&mut self, data: &T) -> &mut Self {
-        let script = ScriptBuf::new_op_return(data);
+    pub fn add_data(&mut self, data: &[u8]) -> &mut Self {
+        let script = Script::new_op_return(data);
        self.add_recipient(script, 0u64);
        self
    }
@@ -759,15 +622,8 @@ impl<'a, D, Cs: CoinSelectionAlgorithm> TxBuilder<'a, D, Cs, CreateTx> {
    /// # use std::str::FromStr;
    /// # use bitcoin::*;
    /// # use bdk::*;
-    /// # use bdk::wallet::ChangeSet;
-    /// # use bdk::wallet::error::CreateTxError;
    /// # use bdk::wallet::tx_builder::CreateTx;
-    /// # use bdk_chain::PersistBackend;
-    /// # use anyhow::Error;
-    /// # let to_address =
-    /// Address::from_str("2N4eQYCbKUHCCTUjBJeHcJp9ok6J2GZsTDt")
-    ///     .unwrap()
-    ///     .assume_checked();
+    /// # let to_address = Address::from_str("2N4eQYCbKUHCCTUjBJeHcJp9ok6J2GZsTDt").unwrap();
    /// # let mut wallet = doctest_wallet!();
    /// let mut tx_builder = wallet.build_tx();
    ///
@@ -776,17 +632,17 @@ impl<'a, D, Cs: CoinSelectionAlgorithm> TxBuilder<'a, D, Cs, CreateTx> {
    ///     .drain_wallet()
    ///     // Send the excess (which is all the coins minus the fee) to this address.
    ///     .drain_to(to_address.script_pubkey())
-    ///     .fee_rate(FeeRate::from_sat_per_vb(5).expect("valid feerate"))
+    ///     .fee_rate(FeeRate::from_sat_per_vb(5.0))
    ///     .enable_rbf();
-    /// let psbt = tx_builder.finish()?;
-    /// # Ok::<(), anyhow::Error>(())
+    /// let (psbt, tx_details) = tx_builder.finish()?;
+    /// # Ok::<(), bdk::Error>(())
    /// ```
    ///
    /// [`allow_shrinking`]: Self::allow_shrinking
    /// [`add_recipient`]: Self::add_recipient
    /// [`add_utxos`]: Self::add_utxos
    /// [`drain_wallet`]: Self::drain_wallet
-    pub fn drain_to(&mut self, script_pubkey: ScriptBuf) -> &mut Self {
+    pub fn drain_to(&mut self, script_pubkey: Script) -> &mut Self {
        self.params.drain_to = Some(script_pubkey);
        self
    }
@@ -804,10 +660,7 @@ impl<'a, D> TxBuilder<'a, D, DefaultCoinSelectionAlgorithm, BumpFee> {
    ///
    /// Returns an `Err` if `script_pubkey` can't be found among the recipients of the
    /// transaction we are bumping.
-    pub fn allow_shrinking(
-        &mut self,
-        script_pubkey: ScriptBuf,
-    ) -> Result<&mut Self, AllowShrinkingError> {
+    pub fn allow_shrinking(&mut self, script_pubkey: Script) -> Result<&mut Self, Error> {
        match self
            .params
            .recipients
@@ -819,16 +672,18 @@ impl<'a, D> TxBuilder<'a, D, DefaultCoinSelectionAlgorithm, BumpFee> {
                self.params.drain_to = Some(script_pubkey);
                Ok(self)
            }
-            None => Err(AllowShrinkingError::MissingScriptPubKey(script_pubkey)),
+            None => Err(Error::Generic(format!(
+                "{} was not in the original transaction",
+                script_pubkey
+            ))),
        }
    }
 }

 /// Ordering of the transaction's inputs and outputs
-#[derive(Default, Debug, Ord, PartialOrd, Eq, PartialEq, Hash, Clone, Copy)]
+#[derive(Debug, Ord, PartialOrd, Eq, PartialEq, Hash, Clone, Copy)]
 pub enum TxOrdering {
    /// Randomized (default)
-    #[default]
    Shuffle,
    /// Unchanged
    Untouched,
@@ -836,6 +691,12 @@ pub enum TxOrdering {
    Bip69Lexicographic,
 }

+impl Default for TxOrdering {
+    fn default() -> Self {
+        TxOrdering::Shuffle
+    }
+}
+
 impl TxOrdering {
    /// Sort transaction inputs and outputs by [`TxOrdering`] variant
    pub fn sort_tx(&self, tx: &mut Transaction) {
@@ -889,10 +750,9 @@ impl RbfValue {
 }

 /// Policy regarding the use of change outputs when creating a transaction
-#[derive(Default, Debug, Ord, PartialOrd, Eq, PartialEq, Hash, Clone, Copy)]
+#[derive(Debug, Ord, PartialOrd, Eq, PartialEq, Hash, Clone, Copy)]
 pub enum ChangeSpendPolicy {
    /// Use both change and non-change outputs (default)
-    #[default]
    ChangeAllowed,
    /// Only use change outputs (see [`TxBuilder::only_spend_change`])
    OnlyChange,
@@ -900,8 +760,14 @@ pub enum ChangeSpendPolicy {
    ChangeForbidden,
 }

+impl Default for ChangeSpendPolicy {
+    fn default() -> Self {
+        ChangeSpendPolicy::ChangeAllowed
+    }
+}
+
 impl ChangeSpendPolicy {
-    pub(crate) fn is_satisfied_by(&self, utxo: &LocalOutput) -> bool {
+    pub(crate) fn is_satisfied_by(&self, utxo: &LocalUtxo) -> bool {
        match self {
            ChangeSpendPolicy::ChangeAllowed => true,
            ChangeSpendPolicy::OnlyChange => utxo.keychain == KeychainKind::Internal,
@@ -927,8 +793,7 @@ mod test {

    use bdk_chain::ConfirmationTime;
    use bitcoin::consensus::deserialize;
-    use bitcoin::hex::FromHex;
-    use bitcoin::TxOut;
+    use bitcoin::hashes::hex::FromHex;

    use super::*;

@@ -999,35 +864,32 @@ mod test {
            .unwrap()
        );

-        assert_eq!(tx.output[0].value.to_sat(), 800);
-        assert_eq!(tx.output[1].script_pubkey, ScriptBuf::from(vec![0xAA]));
-        assert_eq!(
-            tx.output[2].script_pubkey,
-            ScriptBuf::from(vec![0xAA, 0xEE])
-        );
+        assert_eq!(tx.output[0].value, 800);
+        assert_eq!(tx.output[1].script_pubkey, From::from(vec![0xAA]));
+        assert_eq!(tx.output[2].script_pubkey, From::from(vec![0xAA, 0xEE]));
    }

-    fn get_test_utxos() -> Vec<LocalOutput> {
+    fn get_test_utxos() -> Vec<LocalUtxo> {
        use bitcoin::hashes::Hash;

        vec![
-            LocalOutput {
+            LocalUtxo {
                outpoint: OutPoint {
-                    txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(),
+                    txid: bitcoin::Txid::from_inner([0; 32]),
                    vout: 0,
                },
-                txout: TxOut::NULL,
+                txout: Default::default(),
                keychain: KeychainKind::External,
                is_spent: false,
-                confirmation_time: ConfirmationTime::Unconfirmed { last_seen: 0 },
+                confirmation_time: ConfirmationTime::Unconfirmed,
                derivation_index: 0,
            },
-            LocalOutput {
+            LocalUtxo {
                outpoint: OutPoint {
-                    txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(),
+                    txid: bitcoin::Txid::from_inner([0; 32]),
                    vout: 1,
                },
-                txout: TxOut::NULL,
+                txout: Default::default(),
                keychain: KeychainKind::Internal,
                is_spent: false,
                confirmation_time: ConfirmationTime::Confirmed {
--- a/crates/bdk/src/wallet/utils.rs
+++ b/crates/bdk/src/wallet/utils.rs
@@ -10,7 +10,7 @@
 // licenses.

 use bitcoin::secp256k1::{All, Secp256k1};
-use bitcoin::{absolute, Script, Sequence};
+use bitcoin::{LockTime, Script, Sequence};

 use miniscript::{MiniscriptKey, Satisfier, ToPublicKey};

@@ -65,7 +65,7 @@ pub(crate) fn check_nsequence_rbf(rbf: Sequence, csv: Sequence) -> bool {
 }

 impl<Pk: MiniscriptKey + ToPublicKey> Satisfier<Pk> for After {
-    fn check_after(&self, n: absolute::LockTime) -> bool {
+    fn check_after(&self, n: LockTime) -> bool {
        if let Some(current_height) = self.current_height {
            current_height >= n.to_consensus_u32()
        } else {
@@ -119,14 +119,12 @@ mod test {
    pub(crate) const SEQUENCE_LOCKTIME_TYPE_FLAG: u32 = 1 << 22;

    use super::{check_nsequence_rbf, IsDust};
-    use crate::bitcoin::{Address, Network, Sequence};
+    use crate::bitcoin::{Address, Sequence};
    use core::str::FromStr;

    #[test]
    fn test_is_dust() {
        let script_p2pkh = Address::from_str("1GNgwA8JfG7Kc8akJ8opdNWJUihqUztfPe")
-            .unwrap()
-            .require_network(Network::Bitcoin)
            .unwrap()
            .script_pubkey();
        assert!(script_p2pkh.is_p2pkh());
@@ -134,11 +132,9 @@ mod test {
        assert!(!546.is_dust(&script_p2pkh));

        let script_p2wpkh = Address::from_str("bc1qxlh2mnc0yqwas76gqq665qkggee5m98t8yskd8")
-            .unwrap()
-            .require_network(Network::Bitcoin)
            .unwrap()
            .script_pubkey();
-        assert!(script_p2wpkh.is_p2wpkh());
+        assert!(script_p2wpkh.is_v0_p2wpkh());
        assert!(293.is_dust(&script_p2wpkh));
        assert!(!294.is_dust(&script_p2wpkh));
    }
--- a/crates/bdk/tests/common.rs
+++ b/crates/bdk/tests/common.rs
@@ -1,112 +1,46 @@
 #![allow(unused)]
-
-use bdk::{wallet::AddressIndex, KeychainKind, LocalOutput, Wallet};
-use bdk_chain::indexed_tx_graph::Indexer;
+use bdk::{wallet::AddressIndex, Wallet};
 use bdk_chain::{BlockId, ConfirmationTime};
 use bitcoin::hashes::Hash;
-use bitcoin::{
-    transaction, Address, Amount, BlockHash, FeeRate, Network, OutPoint, Transaction, TxIn, TxOut,
-    Txid,
-};
-use std::str::FromStr;
+use bitcoin::{BlockHash, Network, Transaction, TxOut};

-// Return a fake wallet that appears to be funded for testing.
-//
-// The funded wallet containing a tx with a 76_000 sats input and two outputs, one spending 25_000
-// to a foreign address and one returning 50_000 back to the wallet as change. The remaining 1000
-// sats are the transaction fee.
+/// Return a fake wallet that appears to be funded for testing.
 pub fn get_funded_wallet_with_change(
    descriptor: &str,
    change: Option<&str>,
 ) -> (Wallet, bitcoin::Txid) {
    let mut wallet = Wallet::new_no_persist(descriptor, change, Network::Regtest).unwrap();
-    let change_address = wallet.get_address(AddressIndex::New).address;
-    let sendto_address = Address::from_str("bcrt1q3qtze4ys45tgdvguj66zrk4fu6hq3a3v9pfly5")
-        .expect("address")
-        .require_network(Network::Regtest)
-        .unwrap();
+    let address = wallet.get_address(AddressIndex::New).address;

-    let tx0 = Transaction {
-        version: transaction::Version::ONE,
-        lock_time: bitcoin::absolute::LockTime::ZERO,
-        input: vec![TxIn {
-            previous_output: OutPoint {
-                txid: Txid::all_zeros(),
-                vout: 0,
-            },
-            script_sig: Default::default(),
-            sequence: Default::default(),
-            witness: Default::default(),
-        }],
+    let tx = Transaction {
+        version: 1,
+        lock_time: bitcoin::PackedLockTime(0),
+        input: vec![],
        output: vec![TxOut {
-            value: Amount::from_sat(76_000),
-            script_pubkey: change_address.script_pubkey(),
+            value: 50_000,
+            script_pubkey: address.script_pubkey(),
        }],
    };

-    let tx1 = Transaction {
-        version: transaction::Version::ONE,
-        lock_time: bitcoin::absolute::LockTime::ZERO,
-        input: vec![TxIn {
-            previous_output: OutPoint {
-                txid: tx0.txid(),
-                vout: 0,
-            },
-            script_sig: Default::default(),
-            sequence: Default::default(),
-            witness: Default::default(),
-        }],
-        output: vec![
-            TxOut {
-                value: Amount::from_sat(50_000),
-                script_pubkey: change_address.script_pubkey(),
-            },
-            TxOut {
-                value: Amount::from_sat(25_000),
-                script_pubkey: sendto_address.script_pubkey(),
-            },
-        ],
-    };
-
    wallet
        .insert_checkpoint(BlockId {
            height: 1_000,
            hash: BlockHash::all_zeros(),
        })
        .unwrap();
-    wallet
-        .insert_checkpoint(BlockId {
-            height: 2_000,
-            hash: BlockHash::all_zeros(),
-        })
-        .unwrap();
    wallet
        .insert_tx(
-            tx0,
+            tx.clone(),
            ConfirmationTime::Confirmed {
                height: 1_000,
                time: 100,
            },
        )
        .unwrap();
-    wallet
-        .insert_tx(
-            tx1.clone(),
-            ConfirmationTime::Confirmed {
-                height: 2_000,
-                time: 200,
-            },
-        )
-        .unwrap();

-    (wallet, tx1.txid())
+    (wallet, tx.txid())
 }

-// Return a fake wallet that appears to be funded for testing.
-//
-// The funded wallet containing a tx with a 76_000 sats input and two outputs, one spending 25_000
-// to a foreign address and one returning 50_000 back to the wallet as change. The remaining 1000
-// sats are the transaction fee.
 pub fn get_funded_wallet(descriptor: &str) -> (Wallet, bitcoin::Txid) {
    get_funded_wallet_with_change(descriptor, None)
 }
@@ -157,16 +91,3 @@ pub fn get_test_tr_with_taptree_xprv() -> &'static str {
 pub fn get_test_tr_dup_keys() -> &'static str {
    "tr(cNJmN3fH9DDbDt131fQNkVakkpzawJBSeybCUNmP1BovpmGQ45xG,{pk(8aee2b8120a5f157f1223f72b5e62b825831a27a9fdf427db7cc697494d4a642),pk(8aee2b8120a5f157f1223f72b5e62b825831a27a9fdf427db7cc697494d4a642)})"
 }
-
-/// Construct a new [`FeeRate`] from the given raw `sat_vb` feerate. This is
-/// useful in cases where we want to create a feerate from a `f64`, as the
-/// traditional [`FeeRate::from_sat_per_vb`] method will only accept an integer.
-///
-/// **Note** this 'quick and dirty' conversion should only be used when the input
-/// parameter has units of `satoshis/vbyte` **AND** is not expected to overflow,
-/// or else the resulting value will be inaccurate.
-pub fn feerate_unchecked(sat_vb: f64) -> FeeRate {
-    // 1 sat_vb / 4wu_vb * 1000kwu_wu = 250 sat_kwu
-    let sat_kwu = (sat_vb * 250.0).ceil() as u64;
-    FeeRate::from_sat_per_kwu(sat_kwu)
-}
--- a/crates/bdk/tests/psbt.rs
+++ b/crates/bdk/tests/psbt.rs
@@ -1,7 +1,8 @@
-use bdk::bitcoin::{Amount, FeeRate, Psbt, TxIn};
+use bdk::bitcoin::TxIn;
 use bdk::wallet::AddressIndex;
 use bdk::wallet::AddressIndex::New;
-use bdk::{psbt, SignOptions};
+use bdk::{psbt, FeeRate, SignOptions};
+use bitcoin::util::psbt::PartiallySignedTransaction as Psbt;
 use core::str::FromStr;
 mod common;
 use common::*;
@@ -17,7 +18,7 @@ fn test_psbt_malformed_psbt_input_legacy() {
    let send_to = wallet.get_address(AddressIndex::New);
    let mut builder = wallet.build_tx();
    builder.add_recipient(send_to.script_pubkey(), 10_000);
-    let mut psbt = builder.finish().unwrap();
+    let (mut psbt, _) = builder.finish().unwrap();
    psbt.inputs.push(psbt_bip.inputs[0].clone());
    let options = SignOptions {
        trust_witness_utxo: true,
@@ -34,7 +35,7 @@ fn test_psbt_malformed_psbt_input_segwit() {
    let send_to = wallet.get_address(AddressIndex::New);
    let mut builder = wallet.build_tx();
    builder.add_recipient(send_to.script_pubkey(), 10_000);
-    let mut psbt = builder.finish().unwrap();
+    let (mut psbt, _) = builder.finish().unwrap();
    psbt.inputs.push(psbt_bip.inputs[1].clone());
    let options = SignOptions {
        trust_witness_utxo: true,
@@ -50,7 +51,7 @@ fn test_psbt_malformed_tx_input() {
    let send_to = wallet.get_address(AddressIndex::New);
    let mut builder = wallet.build_tx();
    builder.add_recipient(send_to.script_pubkey(), 10_000);
-    let mut psbt = builder.finish().unwrap();
+    let (mut psbt, _) = builder.finish().unwrap();
    psbt.unsigned_tx.input.push(TxIn::default());
    let options = SignOptions {
        trust_witness_utxo: true,
@@ -66,7 +67,7 @@ fn test_psbt_sign_with_finalized() {
    let send_to = wallet.get_address(AddressIndex::New);
    let mut builder = wallet.build_tx();
    builder.add_recipient(send_to.script_pubkey(), 10_000);
-    let mut psbt = builder.finish().unwrap();
+    let (mut psbt, _) = builder.finish().unwrap();

    // add a finalized input
    psbt.inputs.push(psbt_bip.inputs[0].clone());
@@ -81,14 +82,14 @@ fn test_psbt_sign_with_finalized() {
 fn test_psbt_fee_rate_with_witness_utxo() {
    use psbt::PsbtUtils;

-    let expected_fee_rate = FeeRate::from_sat_per_kwu(310);
+    let expected_fee_rate = 1.2345;

    let (mut wallet, _) = get_funded_wallet("wpkh(tprv8ZgxMBicQKsPd3EupYiPRhaMooHKUHJxNsTfYuScep13go8QFfHdtkG9nRkFGb7busX4isf6X9dURGCoKgitaApQ6MupRhZMcELAxTBRJgS/*)");
    let addr = wallet.get_address(New);
    let mut builder = wallet.build_tx();
    builder.drain_to(addr.script_pubkey()).drain_wallet();
-    builder.fee_rate(expected_fee_rate);
-    let mut psbt = builder.finish().unwrap();
+    builder.fee_rate(FeeRate::from_sat_per_vb(expected_fee_rate));
+    let (mut psbt, _) = builder.finish().unwrap();
    let fee_amount = psbt.fee_amount();
    assert!(fee_amount.is_some());

@@ -98,22 +99,22 @@ fn test_psbt_fee_rate_with_witness_utxo() {
    assert!(finalized);

    let finalized_fee_rate = psbt.fee_rate().unwrap();
-    assert!(finalized_fee_rate >= expected_fee_rate);
-    assert!(finalized_fee_rate < unfinalized_fee_rate);
+    assert!(finalized_fee_rate.as_sat_per_vb() >= expected_fee_rate);
+    assert!(finalized_fee_rate.as_sat_per_vb() < unfinalized_fee_rate.as_sat_per_vb());
 }

 #[test]
 fn test_psbt_fee_rate_with_nonwitness_utxo() {
    use psbt::PsbtUtils;

-    let expected_fee_rate = FeeRate::from_sat_per_kwu(310);
+    let expected_fee_rate = 1.2345;

    let (mut wallet, _) = get_funded_wallet("pkh(tprv8ZgxMBicQKsPd3EupYiPRhaMooHKUHJxNsTfYuScep13go8QFfHdtkG9nRkFGb7busX4isf6X9dURGCoKgitaApQ6MupRhZMcELAxTBRJgS/*)");
    let addr = wallet.get_address(New);
    let mut builder = wallet.build_tx();
    builder.drain_to(addr.script_pubkey()).drain_wallet();
-    builder.fee_rate(expected_fee_rate);
-    let mut psbt = builder.finish().unwrap();
+    builder.fee_rate(FeeRate::from_sat_per_vb(expected_fee_rate));
+    let (mut psbt, _) = builder.finish().unwrap();
    let fee_amount = psbt.fee_amount();
    assert!(fee_amount.is_some());
    let unfinalized_fee_rate = psbt.fee_rate().unwrap();
@@ -122,22 +123,22 @@ fn test_psbt_fee_rate_with_nonwitness_utxo() {
    assert!(finalized);

    let finalized_fee_rate = psbt.fee_rate().unwrap();
-    assert!(finalized_fee_rate >= expected_fee_rate);
-    assert!(finalized_fee_rate < unfinalized_fee_rate);
+    assert!(finalized_fee_rate.as_sat_per_vb() >= expected_fee_rate);
+    assert!(finalized_fee_rate.as_sat_per_vb() < unfinalized_fee_rate.as_sat_per_vb());
 }

 #[test]
 fn test_psbt_fee_rate_with_missing_txout() {
    use psbt::PsbtUtils;

-    let expected_fee_rate = FeeRate::from_sat_per_kwu(310);
+    let expected_fee_rate = 1.2345;

    let (mut wpkh_wallet,  _) = get_funded_wallet("wpkh(tprv8ZgxMBicQKsPd3EupYiPRhaMooHKUHJxNsTfYuScep13go8QFfHdtkG9nRkFGb7busX4isf6X9dURGCoKgitaApQ6MupRhZMcELAxTBRJgS/*)");
    let addr = wpkh_wallet.get_address(New);
    let mut builder = wpkh_wallet.build_tx();
    builder.drain_to(addr.script_pubkey()).drain_wallet();
-    builder.fee_rate(expected_fee_rate);
-    let mut wpkh_psbt = builder.finish().unwrap();
+    builder.fee_rate(FeeRate::from_sat_per_vb(expected_fee_rate));
+    let (mut wpkh_psbt, _) = builder.finish().unwrap();

    wpkh_psbt.inputs[0].witness_utxo = None;
    wpkh_psbt.inputs[0].non_witness_utxo = None;
@@ -148,76 +149,10 @@ fn test_psbt_fee_rate_with_missing_txout() {
    let addr = pkh_wallet.get_address(New);
    let mut builder = pkh_wallet.build_tx();
    builder.drain_to(addr.script_pubkey()).drain_wallet();
-    builder.fee_rate(expected_fee_rate);
-    let mut pkh_psbt = builder.finish().unwrap();
+    builder.fee_rate(FeeRate::from_sat_per_vb(expected_fee_rate));
+    let (mut pkh_psbt, _) = builder.finish().unwrap();

    pkh_psbt.inputs[0].non_witness_utxo = None;
    assert!(pkh_psbt.fee_amount().is_none());
    assert!(pkh_psbt.fee_rate().is_none());
 }
-
-#[test]
-fn test_psbt_multiple_internalkey_signers() {
-    use bdk::signer::{SignerContext, SignerOrdering, SignerWrapper};
-    use bdk::KeychainKind;
-    use bitcoin::key::TapTweak;
-    use bitcoin::secp256k1::{schnorr, Keypair, Message, Secp256k1, XOnlyPublicKey};
-    use bitcoin::sighash::{Prevouts, SighashCache, TapSighashType};
-    use bitcoin::{PrivateKey, TxOut};
-    use std::sync::Arc;
-
-    let secp = Secp256k1::new();
-    let wif = "cNJmN3fH9DDbDt131fQNkVakkpzawJBSeybCUNmP1BovpmGQ45xG";
-    let desc = format!("tr({})", wif);
-    let prv = PrivateKey::from_wif(wif).unwrap();
-    let keypair = Keypair::from_secret_key(&secp, &prv.inner);
-
-    let (mut wallet, _) = get_funded_wallet(&desc);
-    let to_spend = wallet.get_balance().total();
-    let send_to = wallet.get_address(AddressIndex::New);
-    let mut builder = wallet.build_tx();
-    builder.drain_to(send_to.script_pubkey()).drain_wallet();
-    let mut psbt = builder.finish().unwrap();
-    let unsigned_tx = psbt.unsigned_tx.clone();
-
-    // Adds a signer for the wrong internal key, bdk should not use this key to sign
-    wallet.add_signer(
-        KeychainKind::External,
-        // A signerordering lower than 100, bdk will use this signer first
-        SignerOrdering(0),
-        Arc::new(SignerWrapper::new(
-            PrivateKey::from_wif("5J5PZqvCe1uThJ3FZeUUFLCh2FuK9pZhtEK4MzhNmugqTmxCdwE").unwrap(),
-            SignerContext::Tap {
-                is_internal_key: true,
-            },
-        )),
-    );
-    let finalized = wallet.sign(&mut psbt, SignOptions::default()).unwrap();
-    assert!(finalized);
-
-    // To verify, we need the signature, message, and pubkey
-    let witness = psbt.inputs[0].final_script_witness.as_ref().unwrap();
-    assert!(!witness.is_empty());
-    let signature = schnorr::Signature::from_slice(witness.iter().next().unwrap()).unwrap();
-
-    // the prevout we're spending
-    let prevouts = &[TxOut {
-        script_pubkey: send_to.script_pubkey(),
-        value: Amount::from_sat(to_spend),
-    }];
-    let prevouts = Prevouts::All(prevouts);
-    let input_index = 0;
-    let mut sighash_cache = SighashCache::new(unsigned_tx);
-    let sighash = sighash_cache
-        .taproot_key_spend_signature_hash(input_index, &prevouts, TapSighashType::Default)
-        .unwrap();
-    let message = Message::from(sighash);
-
-    // add tweak. this was taken from `signer::sign_psbt_schnorr`
-    let keypair = keypair.tap_tweak(&secp, None).to_inner();
-    let (xonlykey, _parity) = XOnlyPublicKey::from_keypair(&keypair);
-
-    // Must verify if we used the correct key to sign
-    let verify_res = secp.verify_schnorr(&signature, &message, &xonlykey);
-    assert!(verify_res.is_ok(), "The wrong internal key was used");
-}
--- a/crates/bdk/tests/wallet.rs
+++ b/crates/bdk/tests/wallet.rs
--- a/crates/bitcoind_rpc/Cargo.toml
+++ b/crates/bitcoind_rpc/Cargo.toml
@@ -1,28 +0,0 @@
-[package]
-name = "bdk_bitcoind_rpc"
-version = "0.8.0"
-edition = "2021"
-rust-version = "1.63"
-homepage = "https://bitcoindevkit.org"
-repository = "https://github.com/bitcoindevkit/bdk"
-documentation = "https://docs.rs/bdk_bitcoind_rpc"
-description = "This crate is used for emitting blockchain data from the `bitcoind` RPC interface."
-license = "MIT OR Apache-2.0"
-readme = "README.md"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]
-# For no-std, remember to enable the bitcoin/no-std feature
-bitcoin = { version = "0.31", default-features = false }
-bitcoincore-rpc = { version = "0.18" }
-bdk_chain = { path = "../chain", version = "0.12", default-features = false }
-
-[dev-dependencies]
-bdk_testenv = { path = "../testenv", default_features = false }
-anyhow = { version = "1" }
-
-[features]
-default = ["std"]
-std = ["bitcoin/std", "bdk_chain/std"]
-serde = ["bitcoin/serde", "bdk_chain/serde"]
--- a/crates/bitcoind_rpc/README.md
+++ b/crates/bitcoind_rpc/README.md
@@ -1,3 +0,0 @@
-# BDK Bitcoind RPC
-
-This crate is used for emitting blockchain data from the `bitcoind` RPC interface.
--- a/crates/bitcoind_rpc/src/lib.rs
+++ b/crates/bitcoind_rpc/src/lib.rs
@@ -1,328 +0,0 @@
-//! This crate is used for emitting blockchain data from the `bitcoind` RPC interface. It does not
-//! use the wallet RPC API, so this crate can be used with wallet-disabled Bitcoin Core nodes.
-//!
-//! [`Emitter`] is the main structure which sources blockchain data from [`bitcoincore_rpc::Client`].
-//!
-//! To only get block updates (exclude mempool transactions), the caller can use
-//! [`Emitter::next_block`] or/and [`Emitter::next_header`] until it returns `Ok(None)` (which means
-//! the chain tip is reached). A separate method, [`Emitter::mempool`] can be used to emit the whole
-//! mempool.
-#![warn(missing_docs)]
-
-use bdk_chain::{local_chain::CheckPoint, BlockId};
-use bitcoin::{block::Header, Block, BlockHash, Transaction};
-pub use bitcoincore_rpc;
-use bitcoincore_rpc::bitcoincore_rpc_json;
-
-/// The [`Emitter`] is used to emit data sourced from [`bitcoincore_rpc::Client`].
-///
-/// Refer to [module-level documentation] for more.
-///
-/// [module-level documentation]: crate
-pub struct Emitter<'c, C> {
-    client: &'c C,
-    start_height: u32,
-
-    /// The checkpoint of the last-emitted block that is in the best chain. If it is later found
-    /// that the block is no longer in the best chain, it will be popped off from here.
-    last_cp: CheckPoint,
-
-    /// The block result returned from rpc of the last-emitted block. As this result contains the
-    /// next block's block hash (which we use to fetch the next block), we set this to `None`
-    /// whenever there are no more blocks, or the next block is no longer in the best chain. This
-    /// gives us an opportunity to re-fetch this result.
-    last_block: Option<bitcoincore_rpc_json::GetBlockResult>,
-
-    /// The latest first-seen epoch of emitted mempool transactions. This is used to determine
-    /// whether a mempool transaction is already emitted.
-    last_mempool_time: usize,
-
-    /// The last emitted block during our last mempool emission. This is used to determine whether
-    /// there has been a reorg since our last mempool emission.
-    last_mempool_tip: Option<u32>,
-}
-
-impl<'c, C: bitcoincore_rpc::RpcApi> Emitter<'c, C> {
-    /// Construct a new [`Emitter`].
-    ///
-    /// `last_cp` informs the emitter of the chain we are starting off with. This way, the emitter
-    /// can start emission from a block that connects to the original chain.
-    ///
-    /// `start_height` starts emission from a given height (if there are no conflicts with the
-    /// original chain).
-    pub fn new(client: &'c C, last_cp: CheckPoint, start_height: u32) -> Self {
-        Self {
-            client,
-            start_height,
-            last_cp,
-            last_block: None,
-            last_mempool_time: 0,
-            last_mempool_tip: None,
-        }
-    }
-
-    /// Emit mempool transactions, alongside their first-seen unix timestamps.
-    ///
-    /// This method emits each transaction only once, unless we cannot guarantee the transaction's
-    /// ancestors are already emitted.
-    ///
-    /// To understand why, consider a receiver which filters transactions based on whether it
-    /// alters the UTXO set of tracked script pubkeys. If an emitted mempool transaction spends a
-    /// tracked UTXO which is confirmed at height `h`, but the receiver has only seen up to block
-    /// of height `h-1`, we want to re-emit this transaction until the receiver has seen the block
-    /// at height `h`.
-    pub fn mempool(&mut self) -> Result<Vec<(Transaction, u64)>, bitcoincore_rpc::Error> {
-        let client = self.client;
-
-        // This is the emitted tip height during the last mempool emission.
-        let prev_mempool_tip = self
-            .last_mempool_tip
-            // We use `start_height - 1` as we cannot guarantee that the block at
-            // `start_height` has been emitted.
-            .unwrap_or(self.start_height.saturating_sub(1));
-
-        // Mempool txs come with a timestamp of when the tx is introduced to the mempool. We keep
-        // track of the latest mempool tx's timestamp to determine whether we have seen a tx
-        // before. `prev_mempool_time` is the previous timestamp and `last_time` records what will
-        // be the new latest timestamp.
-        let prev_mempool_time = self.last_mempool_time;
-        let mut latest_time = prev_mempool_time;
-
-        let txs_to_emit = client
-            .get_raw_mempool_verbose()?
-            .into_iter()
-            .filter_map({
-                let latest_time = &mut latest_time;
-                move |(txid, tx_entry)| -> Option<Result<_, bitcoincore_rpc::Error>> {
-                    let tx_time = tx_entry.time as usize;
-                    if tx_time > *latest_time {
-                        *latest_time = tx_time;
-                    }
-
-                    // Avoid emitting transactions that are already emitted if we can guarantee
-                    // blocks containing ancestors are already emitted. The bitcoind rpc interface
-                    // provides us with the block height that the tx is introduced to the mempool.
-                    // If we have already emitted the block of height, we can assume that all
-                    // ancestor txs have been processed by the receiver.
-                    let is_already_emitted = tx_time <= prev_mempool_time;
-                    let is_within_height = tx_entry.height <= prev_mempool_tip as _;
-                    if is_already_emitted && is_within_height {
-                        return None;
-                    }
-
-                    let tx = match client.get_raw_transaction(&txid, None) {
-                        Ok(tx) => tx,
-                        // the tx is confirmed or evicted since `get_raw_mempool_verbose`
-                        Err(err) if err.is_not_found_error() => return None,
-                        Err(err) => return Some(Err(err)),
-                    };
-
-                    Some(Ok((tx, tx_time as u64)))
-                }
-            })
-            .collect::<Result<Vec<_>, _>>()?;
-
-        self.last_mempool_time = latest_time;
-        self.last_mempool_tip = Some(self.last_cp.height());
-
-        Ok(txs_to_emit)
-    }
-
-    /// Emit the next block height and header (if any).
-    pub fn next_header(&mut self) -> Result<Option<BlockEvent<Header>>, bitcoincore_rpc::Error> {
-        Ok(poll(self, |hash| self.client.get_block_header(hash))?
-            .map(|(checkpoint, block)| BlockEvent { block, checkpoint }))
-    }
-
-    /// Emit the next block height and block (if any).
-    pub fn next_block(&mut self) -> Result<Option<BlockEvent<Block>>, bitcoincore_rpc::Error> {
-        Ok(poll(self, |hash| self.client.get_block(hash))?
-            .map(|(checkpoint, block)| BlockEvent { block, checkpoint }))
-    }
-}
-
-/// A newly emitted block from [`Emitter`].
-#[derive(Debug)]
-pub struct BlockEvent<B> {
-    /// Either a full [`Block`] or [`Header`] of the new block.
-    pub block: B,
-
-    /// The checkpoint of the new block.
-    ///
-    /// A [`CheckPoint`] is a node of a linked list of [`BlockId`]s. This checkpoint is linked to
-    /// all [`BlockId`]s originally passed in [`Emitter::new`] as well as emitted blocks since then.
-    /// These blocks are guaranteed to be of the same chain.
-    ///
-    /// This is important as BDK structures require block-to-apply to be connected with another
-    /// block in the original chain.
-    pub checkpoint: CheckPoint,
-}
-
-impl<B> BlockEvent<B> {
-    /// The block height of this new block.
-    pub fn block_height(&self) -> u32 {
-        self.checkpoint.height()
-    }
-
-    /// The block hash of this new block.
-    pub fn block_hash(&self) -> BlockHash {
-        self.checkpoint.hash()
-    }
-
-    /// The [`BlockId`] of a previous block that this block connects to.
-    ///
-    /// This either returns a [`BlockId`] of a previously emitted block or from the chain we started
-    /// with (passed in as `last_cp` in [`Emitter::new`]).
-    ///
-    /// This value is derived from [`BlockEvent::checkpoint`].
-    pub fn connected_to(&self) -> BlockId {
-        match self.checkpoint.prev() {
-            Some(prev_cp) => prev_cp.block_id(),
-            // there is no previous checkpoint, so just connect with itself
-            None => self.checkpoint.block_id(),
-        }
-    }
-}
-
-enum PollResponse {
-    Block(bitcoincore_rpc_json::GetBlockResult),
-    NoMoreBlocks,
-    /// Fetched block is not in the best chain.
-    BlockNotInBestChain,
-    AgreementFound(bitcoincore_rpc_json::GetBlockResult, CheckPoint),
-    /// Force the genesis checkpoint down the receiver's throat.
-    AgreementPointNotFound(BlockHash),
-}
-
-fn poll_once<C>(emitter: &Emitter<C>) -> Result<PollResponse, bitcoincore_rpc::Error>
-where
-    C: bitcoincore_rpc::RpcApi,
-{
-    let client = emitter.client;
-
-    if let Some(last_res) = &emitter.last_block {
-        let next_hash = if last_res.height < emitter.start_height as _ {
-            // enforce start height
-            let next_hash = client.get_block_hash(emitter.start_height as _)?;
-            // make sure last emission is still in best chain
-            if client.get_block_hash(last_res.height as _)? != last_res.hash {
-                return Ok(PollResponse::BlockNotInBestChain);
-            }
-            next_hash
-        } else {
-            match last_res.nextblockhash {
-                None => return Ok(PollResponse::NoMoreBlocks),
-                Some(next_hash) => next_hash,
-            }
-        };
-
-        let res = client.get_block_info(&next_hash)?;
-        if res.confirmations < 0 {
-            return Ok(PollResponse::BlockNotInBestChain);
-        }
-
-        return Ok(PollResponse::Block(res));
-    }
-
-    for cp in emitter.last_cp.iter() {
-        let res = match client.get_block_info(&cp.hash()) {
-            // block not in best chain
-            Ok(res) if res.confirmations < 0 => continue,
-            Ok(res) => res,
-            Err(e) if e.is_not_found_error() => {
-                if cp.height() > 0 {
-                    continue;
-                }
-                // if we can't find genesis block, we can't create an update that connects
-                break;
-            }
-            Err(e) => return Err(e),
-        };
-
-        // agreement point found
-        return Ok(PollResponse::AgreementFound(res, cp));
-    }
-
-    let genesis_hash = client.get_block_hash(0)?;
-    Ok(PollResponse::AgreementPointNotFound(genesis_hash))
-}
-
-fn poll<C, V, F>(
-    emitter: &mut Emitter<C>,
-    get_item: F,
-) -> Result<Option<(CheckPoint, V)>, bitcoincore_rpc::Error>
-where
-    C: bitcoincore_rpc::RpcApi,
-    F: Fn(&BlockHash) -> Result<V, bitcoincore_rpc::Error>,
-{
-    loop {
-        match poll_once(emitter)? {
-            PollResponse::Block(res) => {
-                let height = res.height as u32;
-                let hash = res.hash;
-                let item = get_item(&hash)?;
-
-                let new_cp = emitter
-                    .last_cp
-                    .clone()
-                    .push(BlockId { height, hash })
-                    .expect("must push");
-                emitter.last_cp = new_cp.clone();
-                emitter.last_block = Some(res);
-                return Ok(Some((new_cp, item)));
-            }
-            PollResponse::NoMoreBlocks => {
-                emitter.last_block = None;
-                return Ok(None);
-            }
-            PollResponse::BlockNotInBestChain => {
-                emitter.last_block = None;
-                continue;
-            }
-            PollResponse::AgreementFound(res, cp) => {
-                let agreement_h = res.height as u32;
-
-                // The tip during the last mempool emission needs to in the best chain, we reduce
-                // it if it is not.
-                if let Some(h) = emitter.last_mempool_tip.as_mut() {
-                    if *h > agreement_h {
-                        *h = agreement_h;
-                    }
-                }
-
-                // get rid of evicted blocks
-                emitter.last_cp = cp;
-                emitter.last_block = Some(res);
-                continue;
-            }
-            PollResponse::AgreementPointNotFound(genesis_hash) => {
-                emitter.last_cp = CheckPoint::new(BlockId {
-                    height: 0,
-                    hash: genesis_hash,
-                });
-                emitter.last_block = None;
-                continue;
-            }
-        }
-    }
-}
-
-/// Extends [`bitcoincore_rpc::Error`].
-pub trait BitcoindRpcErrorExt {
-    /// Returns whether the error is a "not found" error.
-    ///
-    /// This is useful since [`Emitter`] emits [`Result<_, bitcoincore_rpc::Error>`]s as
-    /// [`Iterator::Item`].
-    fn is_not_found_error(&self) -> bool;
-}
-
-impl BitcoindRpcErrorExt for bitcoincore_rpc::Error {
-    fn is_not_found_error(&self) -> bool {
-        if let bitcoincore_rpc::Error::JsonRpc(bitcoincore_rpc::jsonrpc::Error::Rpc(rpc_err)) = self
-        {
-            rpc_err.code == -5
-        } else {
-            false
-        }
-    }
-}
--- a/crates/bitcoind_rpc/tests/test_emitter.rs
+++ b/crates/bitcoind_rpc/tests/test_emitter.rs
@@ -1,750 +0,0 @@
-use std::collections::{BTreeMap, BTreeSet};
-
-use bdk_bitcoind_rpc::Emitter;
-use bdk_chain::{
-    bitcoin::{Address, Amount, Txid},
-    keychain::Balance,
-    local_chain::{self, CheckPoint, LocalChain},
-    Append, BlockId, IndexedTxGraph, SpkTxOutIndex,
-};
-use bdk_testenv::TestEnv;
-use bitcoin::{hashes::Hash, Block, OutPoint, ScriptBuf, WScriptHash};
-use bitcoincore_rpc::RpcApi;
-
-/// Ensure that blocks are emitted in order even after reorg.
-///
-/// 1. Mine 101 blocks.
-/// 2. Emit blocks from [`Emitter`] and update the [`LocalChain`].
-/// 3. Reorg highest 6 blocks.
-/// 4. Emit blocks from [`Emitter`] and re-update the [`LocalChain`].
-#[test]
-pub fn test_sync_local_chain() -> anyhow::Result<()> {
-    let env = TestEnv::new()?;
-    let network_tip = env.rpc_client().get_block_count()?;
-    let (mut local_chain, _) = LocalChain::from_genesis_hash(env.rpc_client().get_block_hash(0)?);
-    let mut emitter = Emitter::new(env.rpc_client(), local_chain.tip(), 0);
-
-    // Mine some blocks and return the actual block hashes.
-    // Because initializing `ElectrsD` already mines some blocks, we must include those too when
-    // returning block hashes.
-    let exp_hashes = {
-        let mut hashes = (0..=network_tip)
-            .map(|height| env.rpc_client().get_block_hash(height))
-            .collect::<Result<Vec<_>, _>>()?;
-        hashes.extend(env.mine_blocks(101 - network_tip as usize, None)?);
-        hashes
-    };
-
-    // See if the emitter outputs the right blocks.
-    println!("first sync:");
-    while let Some(emission) = emitter.next_block()? {
-        let height = emission.block_height();
-        let hash = emission.block_hash();
-        assert_eq!(
-            emission.block_hash(),
-            exp_hashes[height as usize],
-            "emitted block hash is unexpected"
-        );
-
-        assert_eq!(
-            local_chain.apply_update(local_chain::Update {
-                tip: emission.checkpoint,
-                introduce_older_blocks: false,
-            })?,
-            BTreeMap::from([(height, Some(hash))]),
-            "chain update changeset is unexpected",
-        );
-    }
-
-    assert_eq!(
-        local_chain
-            .iter_checkpoints()
-            .map(|cp| (cp.height(), cp.hash()))
-            .collect::<BTreeSet<_>>(),
-        exp_hashes
-            .iter()
-            .enumerate()
-            .map(|(i, hash)| (i as u32, *hash))
-            .collect::<BTreeSet<_>>(),
-        "final local_chain state is unexpected",
-    );
-
-    // Perform reorg.
-    let reorged_blocks = env.reorg(6)?;
-    let exp_hashes = exp_hashes
-        .iter()
-        .take(exp_hashes.len() - reorged_blocks.len())
-        .chain(&reorged_blocks)
-        .cloned()
-        .collect::<Vec<_>>();
-
-    // See if the emitter outputs the right blocks.
-    println!("after reorg:");
-    let mut exp_height = exp_hashes.len() - reorged_blocks.len();
-    while let Some(emission) = emitter.next_block()? {
-        let height = emission.block_height();
-        let hash = emission.block_hash();
-        assert_eq!(
-            height, exp_height as u32,
-            "emitted block has unexpected height"
-        );
-
-        assert_eq!(
-            hash, exp_hashes[height as usize],
-            "emitted block is unexpected"
-        );
-
-        assert_eq!(
-            local_chain.apply_update(local_chain::Update {
-                tip: emission.checkpoint,
-                introduce_older_blocks: false,
-            })?,
-            if exp_height == exp_hashes.len() - reorged_blocks.len() {
-                core::iter::once((height, Some(hash)))
-                    .chain((height + 1..exp_hashes.len() as u32).map(|h| (h, None)))
-                    .collect::<bdk_chain::local_chain::ChangeSet>()
-            } else {
-                BTreeMap::from([(height, Some(hash))])
-            },
-            "chain update changeset is unexpected",
-        );
-
-        exp_height += 1;
-    }
-
-    assert_eq!(
-        local_chain
-            .iter_checkpoints()
-            .map(|cp| (cp.height(), cp.hash()))
-            .collect::<BTreeSet<_>>(),
-        exp_hashes
-            .iter()
-            .enumerate()
-            .map(|(i, hash)| (i as u32, *hash))
-            .collect::<BTreeSet<_>>(),
-        "final local_chain state is unexpected after reorg",
-    );
-
-    Ok(())
-}
-
-/// Ensure that [`EmittedUpdate::into_tx_graph_update`] behaves appropriately for both mempool and
-/// block updates.
-///
-/// [`EmittedUpdate::into_tx_graph_update`]: bdk_bitcoind_rpc::EmittedUpdate::into_tx_graph_update
-#[test]
-fn test_into_tx_graph() -> anyhow::Result<()> {
-    let env = TestEnv::new()?;
-
-    println!("getting new addresses!");
-    let addr_0 = env
-        .rpc_client()
-        .get_new_address(None, None)?
-        .assume_checked();
-    let addr_1 = env
-        .rpc_client()
-        .get_new_address(None, None)?
-        .assume_checked();
-    let addr_2 = env
-        .rpc_client()
-        .get_new_address(None, None)?
-        .assume_checked();
-    println!("got new addresses!");
-
-    println!("mining block!");
-    env.mine_blocks(101, None)?;
-    println!("mined blocks!");
-
-    let (mut chain, _) = LocalChain::from_genesis_hash(env.rpc_client().get_block_hash(0)?);
-    let mut indexed_tx_graph = IndexedTxGraph::<BlockId, _>::new({
-        let mut index = SpkTxOutIndex::<usize>::default();
-        index.insert_spk(0, addr_0.script_pubkey());
-        index.insert_spk(1, addr_1.script_pubkey());
-        index.insert_spk(2, addr_2.script_pubkey());
-        index
-    });
-
-    let emitter = &mut Emitter::new(env.rpc_client(), chain.tip(), 0);
-
-    while let Some(emission) = emitter.next_block()? {
-        let height = emission.block_height();
-        let _ = chain.apply_update(local_chain::Update {
-            tip: emission.checkpoint,
-            introduce_older_blocks: false,
-        })?;
-        let indexed_additions = indexed_tx_graph.apply_block_relevant(&emission.block, height);
-        assert!(indexed_additions.is_empty());
-    }
-
-    // send 3 txs to a tracked address, these txs will be in the mempool
-    let exp_txids = {
-        let mut txids = BTreeSet::new();
-        for _ in 0..3 {
-            txids.insert(env.rpc_client().send_to_address(
-                &addr_0,
-                Amount::from_sat(10_000),
-                None,
-                None,
-                None,
-                None,
-                None,
-                None,
-            )?);
-        }
-        txids
-    };
-
-    // expect that the next block should be none and we should get 3 txs from mempool
-    {
-        // next block should be `None`
-        assert!(emitter.next_block()?.is_none());
-
-        let mempool_txs = emitter.mempool()?;
-        let indexed_additions = indexed_tx_graph.batch_insert_unconfirmed(mempool_txs);
-        assert_eq!(
-            indexed_additions
-                .graph
-                .txs
-                .iter()
-                .map(|tx| tx.txid())
-                .collect::<BTreeSet<Txid>>(),
-            exp_txids,
-            "changeset should have the 3 mempool transactions",
-        );
-        assert!(indexed_additions.graph.anchors.is_empty());
-    }
-
-    // mine a block that confirms the 3 txs
-    let exp_block_hash = env.mine_blocks(1, None)?[0];
-    let exp_block_height = env.rpc_client().get_block_info(&exp_block_hash)?.height as u32;
-    let exp_anchors = exp_txids
-        .iter()
-        .map({
-            let anchor = BlockId {
-                height: exp_block_height,
-                hash: exp_block_hash,
-            };
-            move |&txid| (anchor, txid)
-        })
-        .collect::<BTreeSet<_>>();
-
-    // must receive mined block which will confirm the transactions.
-    {
-        let emission = emitter.next_block()?.expect("must get mined block");
-        let height = emission.block_height();
-        let _ = chain.apply_update(local_chain::Update {
-            tip: emission.checkpoint,
-            introduce_older_blocks: false,
-        })?;
-        let indexed_additions = indexed_tx_graph.apply_block_relevant(&emission.block, height);
-        assert!(indexed_additions.graph.txs.is_empty());
-        assert!(indexed_additions.graph.txouts.is_empty());
-        assert_eq!(indexed_additions.graph.anchors, exp_anchors);
-    }
-
-    Ok(())
-}
-
-/// Ensure next block emitted after reorg is at reorg height.
-///
-/// After a reorg, if the last-emitted block height is equal or greater than the reorg height, and
-/// the fallback height is equal to or lower than the reorg height, the next block/header emission
-/// should be at the reorg height.
-///
-/// TODO: If the reorg height is lower than the fallback height, how do we find a block height to
-/// emit that can connect with our receiver chain?
-#[test]
-fn ensure_block_emitted_after_reorg_is_at_reorg_height() -> anyhow::Result<()> {
-    const EMITTER_START_HEIGHT: usize = 100;
-    const CHAIN_TIP_HEIGHT: usize = 110;
-
-    let env = TestEnv::new()?;
-    let mut emitter = Emitter::new(
-        env.rpc_client(),
-        CheckPoint::new(BlockId {
-            height: 0,
-            hash: env.rpc_client().get_block_hash(0)?,
-        }),
-        EMITTER_START_HEIGHT as _,
-    );
-
-    env.mine_blocks(CHAIN_TIP_HEIGHT, None)?;
-    while emitter.next_header()?.is_some() {}
-
-    for reorg_count in 1..=10 {
-        let replaced_blocks = env.reorg_empty_blocks(reorg_count)?;
-        let next_emission = emitter.next_header()?.expect("must emit block after reorg");
-        assert_eq!(
-            (
-                next_emission.block_height() as usize,
-                next_emission.block_hash()
-            ),
-            replaced_blocks[0],
-            "block emitted after reorg should be at the reorg height"
-        );
-        while emitter.next_header()?.is_some() {}
-    }
-
-    Ok(())
-}
-
-fn process_block(
-    recv_chain: &mut LocalChain,
-    recv_graph: &mut IndexedTxGraph<BlockId, SpkTxOutIndex<()>>,
-    block: Block,
-    block_height: u32,
-) -> anyhow::Result<()> {
-    recv_chain
-        .apply_update(CheckPoint::from_header(&block.header, block_height).into_update(false))?;
-    let _ = recv_graph.apply_block(block, block_height);
-    Ok(())
-}
-
-fn sync_from_emitter<C>(
-    recv_chain: &mut LocalChain,
-    recv_graph: &mut IndexedTxGraph<BlockId, SpkTxOutIndex<()>>,
-    emitter: &mut Emitter<C>,
-) -> anyhow::Result<()>
-where
-    C: bitcoincore_rpc::RpcApi,
-{
-    while let Some(emission) = emitter.next_block()? {
-        let height = emission.block_height();
-        process_block(recv_chain, recv_graph, emission.block, height)?;
-    }
-    Ok(())
-}
-
-fn get_balance(
-    recv_chain: &LocalChain,
-    recv_graph: &IndexedTxGraph<BlockId, SpkTxOutIndex<()>>,
-) -> anyhow::Result<Balance> {
-    let chain_tip = recv_chain.tip().block_id();
-    let outpoints = recv_graph.index.outpoints().clone();
-    let balance = recv_graph
-        .graph()
-        .balance(recv_chain, chain_tip, outpoints, |_, _| true);
-    Ok(balance)
-}
-
-/// If a block is reorged out, ensure that containing transactions that do not exist in the
-/// replacement block(s) become unconfirmed.
-#[test]
-fn tx_can_become_unconfirmed_after_reorg() -> anyhow::Result<()> {
-    const PREMINE_COUNT: usize = 101;
-    const ADDITIONAL_COUNT: usize = 11;
-    const SEND_AMOUNT: Amount = Amount::from_sat(10_000);
-
-    let env = TestEnv::new()?;
-    let mut emitter = Emitter::new(
-        env.rpc_client(),
-        CheckPoint::new(BlockId {
-            height: 0,
-            hash: env.rpc_client().get_block_hash(0)?,
-        }),
-        0,
-    );
-
-    // setup addresses
-    let addr_to_mine = env
-        .rpc_client()
-        .get_new_address(None, None)?
-        .assume_checked();
-    let spk_to_track = ScriptBuf::new_p2wsh(&WScriptHash::all_zeros());
-    let addr_to_track = Address::from_script(&spk_to_track, bitcoin::Network::Regtest)?;
-
-    // setup receiver
-    let (mut recv_chain, _) = LocalChain::from_genesis_hash(env.rpc_client().get_block_hash(0)?);
-    let mut recv_graph = IndexedTxGraph::<BlockId, _>::new({
-        let mut recv_index = SpkTxOutIndex::default();
-        recv_index.insert_spk((), spk_to_track.clone());
-        recv_index
-    });
-
-    // mine and sync receiver up to tip
-    env.mine_blocks(PREMINE_COUNT, Some(addr_to_mine))?;
-
-    // create transactions that are tracked by our receiver
-    for _ in 0..ADDITIONAL_COUNT {
-        let txid = env.send(&addr_to_track, SEND_AMOUNT)?;
-
-        // lock outputs that send to `addr_to_track`
-        let outpoints_to_lock = env
-            .rpc_client()
-            .get_transaction(&txid, None)?
-            .transaction()?
-            .output
-            .into_iter()
-            .enumerate()
-            .filter(|(_, txo)| txo.script_pubkey == spk_to_track)
-            .map(|(vout, _)| OutPoint::new(txid, vout as _))
-            .collect::<Vec<_>>();
-        env.rpc_client().lock_unspent(&outpoints_to_lock)?;
-
-        let _ = env.mine_blocks(1, None)?;
-    }
-
-    // get emitter up to tip
-    sync_from_emitter(&mut recv_chain, &mut recv_graph, &mut emitter)?;
-
-    assert_eq!(
-        get_balance(&recv_chain, &recv_graph)?,
-        Balance {
-            confirmed: SEND_AMOUNT.to_sat() * ADDITIONAL_COUNT as u64,
-            ..Balance::default()
-        },
-        "initial balance must be correct",
-    );
-
-    // perform reorgs with different depths
-    for reorg_count in 1..=ADDITIONAL_COUNT {
-        env.reorg_empty_blocks(reorg_count)?;
-        sync_from_emitter(&mut recv_chain, &mut recv_graph, &mut emitter)?;
-
-        assert_eq!(
-            get_balance(&recv_chain, &recv_graph)?,
-            Balance {
-                confirmed: SEND_AMOUNT.to_sat() * (ADDITIONAL_COUNT - reorg_count) as u64,
-                trusted_pending: SEND_AMOUNT.to_sat() * reorg_count as u64,
-                ..Balance::default()
-            },
-            "reorg_count: {}",
-            reorg_count,
-        );
-    }
-
-    Ok(())
-}
-
-/// Ensure avoid-re-emission-logic is sound when [`Emitter`] is synced to tip.
-///
-/// The receiver (bdk_chain structures) is synced to the chain tip, and there is txs in the mempool.
-/// When we call Emitter::mempool multiple times, mempool txs should not be re-emitted, even if the
-/// chain tip is extended.
-#[test]
-fn mempool_avoids_re_emission() -> anyhow::Result<()> {
-    const BLOCKS_TO_MINE: usize = 101;
-    const MEMPOOL_TX_COUNT: usize = 2;
-
-    let env = TestEnv::new()?;
-    let mut emitter = Emitter::new(
-        env.rpc_client(),
-        CheckPoint::new(BlockId {
-            height: 0,
-            hash: env.rpc_client().get_block_hash(0)?,
-        }),
-        0,
-    );
-
-    // mine blocks and sync up emitter
-    let addr = env
-        .rpc_client()
-        .get_new_address(None, None)?
-        .assume_checked();
-    env.mine_blocks(BLOCKS_TO_MINE, Some(addr.clone()))?;
-    while emitter.next_header()?.is_some() {}
-
-    // have some random txs in mempool
-    let exp_txids = (0..MEMPOOL_TX_COUNT)
-        .map(|_| env.send(&addr, Amount::from_sat(2100)))
-        .collect::<Result<BTreeSet<Txid>, _>>()?;
-
-    // the first emission should include all transactions
-    let emitted_txids = emitter
-        .mempool()?
-        .into_iter()
-        .map(|(tx, _)| tx.txid())
-        .collect::<BTreeSet<Txid>>();
-    assert_eq!(
-        emitted_txids, exp_txids,
-        "all mempool txs should be emitted"
-    );
-
-    // second emission should be empty
-    assert!(
-        emitter.mempool()?.is_empty(),
-        "second emission should be empty"
-    );
-
-    // mine empty blocks + sync up our emitter -> we should still not re-emit
-    for _ in 0..BLOCKS_TO_MINE {
-        env.mine_empty_block()?;
-    }
-    while emitter.next_header()?.is_some() {}
-    assert!(
-        emitter.mempool()?.is_empty(),
-        "third emission, after chain tip is extended, should also be empty"
-    );
-
-    Ok(())
-}
-
-/// Ensure mempool tx is still re-emitted if [`Emitter`] has not reached the tx's introduction
-/// height.
-///
-/// We introduce a mempool tx after each block, where blocks are empty (does not confirm previous
-/// mempool txs). Then we emit blocks from [`Emitter`] (intertwining `mempool` calls). We check
-/// that `mempool` should always re-emit txs that have introduced at a height greater than the last
-/// emitted block height.
-#[test]
-fn mempool_re_emits_if_tx_introduction_height_not_reached() -> anyhow::Result<()> {
-    const PREMINE_COUNT: usize = 101;
-    const MEMPOOL_TX_COUNT: usize = 21;
-
-    let env = TestEnv::new()?;
-    let mut emitter = Emitter::new(
-        env.rpc_client(),
-        CheckPoint::new(BlockId {
-            height: 0,
-            hash: env.rpc_client().get_block_hash(0)?,
-        }),
-        0,
-    );
-
-    // mine blocks to get initial balance, sync emitter up to tip
-    let addr = env
-        .rpc_client()
-        .get_new_address(None, None)?
-        .assume_checked();
-    env.mine_blocks(PREMINE_COUNT, Some(addr.clone()))?;
-    while emitter.next_header()?.is_some() {}
-
-    // mine blocks to introduce txs to mempool at different heights
-    let tx_introductions = (0..MEMPOOL_TX_COUNT)
-        .map(|_| -> anyhow::Result<_> {
-            let (height, _) = env.mine_empty_block()?;
-            let txid = env.send(&addr, Amount::from_sat(2100))?;
-            Ok((height, txid))
-        })
-        .collect::<anyhow::Result<BTreeSet<_>>>()?;
-
-    assert_eq!(
-        emitter
-            .mempool()?
-            .into_iter()
-            .map(|(tx, _)| tx.txid())
-            .collect::<BTreeSet<_>>(),
-        tx_introductions.iter().map(|&(_, txid)| txid).collect(),
-        "first mempool emission should include all txs",
-    );
-    assert_eq!(
-        emitter
-            .mempool()?
-            .into_iter()
-            .map(|(tx, _)| tx.txid())
-            .collect::<BTreeSet<_>>(),
-        tx_introductions.iter().map(|&(_, txid)| txid).collect(),
-        "second mempool emission should still include all txs",
-    );
-
-    // At this point, the emitter has seen all mempool transactions. It should only re-emit those
-    // that have introduction heights less than the emitter's last-emitted block tip.
-    while let Some(emission) = emitter.next_header()? {
-        let height = emission.block_height();
-        // We call `mempool()` twice.
-        // The second call (at height `h`) should skip the tx introduced at height `h`.
-        for try_index in 0..2 {
-            let exp_txids = tx_introductions
-                .range((height as usize + try_index, Txid::all_zeros())..)
-                .map(|&(_, txid)| txid)
-                .collect::<BTreeSet<_>>();
-            let emitted_txids = emitter
-                .mempool()?
-                .into_iter()
-                .map(|(tx, _)| tx.txid())
-                .collect::<BTreeSet<_>>();
-            assert_eq!(
-                emitted_txids, exp_txids,
-                "\n emission {} (try {}) must only contain txs introduced at that height or lower: \n\t missing: {:?} \n\t extra: {:?}",
-                height,
-                try_index,
-                exp_txids
-                    .difference(&emitted_txids)
-                    .map(|txid| (txid, tx_introductions.iter().find_map(|(h, id)| if id == txid { Some(h) } else { None }).unwrap()))
-                    .collect::<Vec<_>>(),
-                emitted_txids
-                    .difference(&exp_txids)
-                    .map(|txid| (txid, tx_introductions.iter().find_map(|(h, id)| if id == txid { Some(h) } else { None }).unwrap()))
-                    .collect::<Vec<_>>(),
-            );
-        }
-    }
-
-    Ok(())
-}
-
-/// Ensure we force re-emit all mempool txs after reorg.
-#[test]
-fn mempool_during_reorg() -> anyhow::Result<()> {
-    const TIP_DIFF: usize = 10;
-    const PREMINE_COUNT: usize = 101;
-
-    let env = TestEnv::new()?;
-    let mut emitter = Emitter::new(
-        env.rpc_client(),
-        CheckPoint::new(BlockId {
-            height: 0,
-            hash: env.rpc_client().get_block_hash(0)?,
-        }),
-        0,
-    );
-
-    // mine blocks to get initial balance
-    let addr = env
-        .rpc_client()
-        .get_new_address(None, None)?
-        .assume_checked();
-    env.mine_blocks(PREMINE_COUNT, Some(addr.clone()))?;
-
-    // introduce mempool tx at each block extension
-    for _ in 0..TIP_DIFF {
-        env.mine_empty_block()?;
-        env.send(&addr, Amount::from_sat(2100))?;
-    }
-
-    // sync emitter to tip, first mempool emission should include all txs (as we haven't emitted
-    // from the mempool yet)
-    while emitter.next_header()?.is_some() {}
-    assert_eq!(
-        emitter
-            .mempool()?
-            .into_iter()
-            .map(|(tx, _)| tx.txid())
-            .collect::<BTreeSet<_>>(),
-        env.rpc_client()
-            .get_raw_mempool()?
-            .into_iter()
-            .collect::<BTreeSet<_>>(),
-        "first mempool emission should include all txs",
-    );
-
-    // perform reorgs at different heights, these reorgs will not confirm transactions in the
-    // mempool
-    for reorg_count in 1..TIP_DIFF {
-        println!("REORG COUNT: {}", reorg_count);
-        env.reorg_empty_blocks(reorg_count)?;
-
-        // This is a map of mempool txids to tip height where the tx was introduced to the mempool
-        // we recalculate this at every loop as reorgs may evict transactions from mempool. We use
-        // the introduction height to determine whether we expect a tx to appear in a mempool
-        // emission.
-        // TODO: How can have have reorg logic in `TestEnv` NOT blacklast old blocks first?
-        let tx_introductions = dbg!(env
-            .rpc_client()
-            .get_raw_mempool_verbose()?
-            .into_iter()
-            .map(|(txid, entry)| (txid, entry.height as usize))
-            .collect::<BTreeMap<_, _>>());
-
-        // `next_header` emits the replacement block of the reorg
-        if let Some(emission) = emitter.next_header()? {
-            let height = emission.block_height();
-            println!("\t- replacement height: {}", height);
-
-            // the mempool emission (that follows the first block emission after reorg) should only
-            // include mempool txs introduced at reorg height or greater
-            let mempool = emitter
-                .mempool()?
-                .into_iter()
-                .map(|(tx, _)| tx.txid())
-                .collect::<BTreeSet<_>>();
-            let exp_mempool = tx_introductions
-                .iter()
-                .filter(|(_, &intro_h)| intro_h >= (height as usize))
-                .map(|(&txid, _)| txid)
-                .collect::<BTreeSet<_>>();
-            assert_eq!(
-                mempool, exp_mempool,
-                "the first mempool emission after reorg should only include mempool txs introduced at reorg height or greater"
-            );
-
-            let mempool = emitter
-                .mempool()?
-                .into_iter()
-                .map(|(tx, _)| tx.txid())
-                .collect::<BTreeSet<_>>();
-            let exp_mempool = tx_introductions
-                .iter()
-                .filter(|&(_, &intro_height)| intro_height > (height as usize))
-                .map(|(&txid, _)| txid)
-                .collect::<BTreeSet<_>>();
-            assert_eq!(
-                mempool, exp_mempool,
-                "following mempool emissions after reorg should exclude mempool introduction heights <= last emitted block height: \n\t missing: {:?} \n\t extra: {:?}",
-                exp_mempool
-                    .difference(&mempool)
-                    .map(|txid| (txid, tx_introductions.get(txid).unwrap()))
-                    .collect::<Vec<_>>(),
-                mempool
-                    .difference(&exp_mempool)
-                    .map(|txid| (txid, tx_introductions.get(txid).unwrap()))
-                    .collect::<Vec<_>>(),
-            );
-        }
-
-        // sync emitter to tip
-        while emitter.next_header()?.is_some() {}
-    }
-
-    Ok(())
-}
-
-/// If blockchain re-org includes the start height, emit new start height block
-///
-/// 1. mine 101 blocks
-/// 2. emit blocks 99a, 100a
-/// 3. invalidate blocks 99a, 100a, 101a
-/// 4. mine new blocks 99b, 100b, 101b
-/// 5. emit block 99b
-///
-/// The block hash of 99b should be different than 99a, but their previous block hashes should
-/// be the same.
-#[test]
-fn no_agreement_point() -> anyhow::Result<()> {
-    const PREMINE_COUNT: usize = 101;
-
-    let env = TestEnv::new()?;
-
-    // start height is 99
-    let mut emitter = Emitter::new(
-        env.rpc_client(),
-        CheckPoint::new(BlockId {
-            height: 0,
-            hash: env.rpc_client().get_block_hash(0)?,
-        }),
-        (PREMINE_COUNT - 2) as u32,
-    );
-
-    // mine 101 blocks
-    env.mine_blocks(PREMINE_COUNT, None)?;
-
-    // emit block 99a
-    let block_header_99a = emitter.next_header()?.expect("block 99a header").block;
-    let block_hash_99a = block_header_99a.block_hash();
-    let block_hash_98a = block_header_99a.prev_blockhash;
-
-    // emit block 100a
-    let block_header_100a = emitter.next_header()?.expect("block 100a header").block;
-    let block_hash_100a = block_header_100a.block_hash();
-
-    // get hash for block 101a
-    let block_hash_101a = env.rpc_client().get_block_hash(101)?;
-
-    // invalidate blocks 99a, 100a, 101a
-    env.rpc_client().invalidate_block(&block_hash_99a)?;
-    env.rpc_client().invalidate_block(&block_hash_100a)?;
-    env.rpc_client().invalidate_block(&block_hash_101a)?;
-
-    // mine new blocks 99b, 100b, 101b
-    env.mine_blocks(3, None)?;
-
-    // emit block header 99b
-    let block_header_99b = emitter.next_header()?.expect("block 99b header").block;
-    let block_hash_99b = block_header_99b.block_hash();
-    let block_hash_98b = block_header_99b.prev_blockhash;
-
-    assert_ne!(block_hash_99a, block_hash_99b);
-    assert_eq!(block_hash_98a, block_hash_98b);
-
-    Ok(())
-}
--- a/crates/chain/Cargo.toml
+++ b/crates/chain/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
 name = "bdk_chain"
-version = "0.12.0"
+version = "0.4.0"
 edition = "2021"
-rust-version = "1.63"
+rust-version = "1.57"
 homepage = "https://bitcoindevkit.org"
 repository = "https://github.com/bitcoindevkit/bdk"
 documentation = "https://docs.rs/bdk_chain"
@@ -13,19 +13,18 @@ readme = "README.md"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

 [dependencies]
-# For no-std, remember to enable the bitcoin/no-std feature
-bitcoin = { version = "0.31.0", default-features = false }
-serde_crate = { package = "serde", version = "1", optional = true, features = ["derive", "rc"] }
+bitcoin = { version = "0.29" }
+serde_crate = { package = "serde", version = "1", optional = true, features = ["derive"] }

 # Use hashbrown as a feature flag to have HashSet and HashMap from it.
-hashbrown = { version = "0.9.1", optional = true, features = ["serde"] }
-miniscript = { version = "11.0.0", optional = true, default-features = false }
+# note version 0.13 breaks outs MSRV.
+hashbrown = { version = "0.12", optional = true,  features = ["serde"] }
+miniscript = { version = "9.0.0", optional = true  }

 [dev-dependencies]
 rand = "0.8"
-proptest = "1.2.0"

 [features]
-default = ["std"]
-std = ["bitcoin/std", "miniscript/std"]
-serde = ["serde_crate", "bitcoin/serde"]
+default = ["std", "miniscript"]
+std = []
+serde = ["serde_crate", "bitcoin/serde" ]
--- a/crates/chain/src/chain_data.rs
+++ b/crates/chain/src/chain_data.rs
@@ -1,45 +1,75 @@
 use bitcoin::{hashes::Hash, BlockHash, OutPoint, TxOut, Txid};

-use crate::{Anchor, AnchorFromBlockPosition, COINBASE_MATURITY};
+use crate::{
+    sparse_chain::{self, ChainPosition},
+    COINBASE_MATURITY,
+};

-/// Represents the observed position of some chain data.
-///
-/// The generic `A` should be a [`Anchor`] implementation.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, core::hash::Hash)]
-pub enum ChainPosition<A> {
-    /// The chain data is seen as confirmed, and in anchored by `A`.
-    Confirmed(A),
-    /// The chain data is not confirmed and last seen in the mempool at this timestamp.
-    Unconfirmed(u64),
+/// Represents the height at which a transaction is confirmed.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[cfg_attr(
+    feature = "serde",
+    derive(serde::Deserialize, serde::Serialize),
+    serde(crate = "serde_crate")
+)]
+pub enum TxHeight {
+    Confirmed(u32),
+    Unconfirmed,
 }

-impl<A> ChainPosition<A> {
-    /// Returns whether [`ChainPosition`] is confirmed or not.
+impl Default for TxHeight {
+    fn default() -> Self {
+        Self::Unconfirmed
+    }
+}
+
+impl core::fmt::Display for TxHeight {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        match self {
+            Self::Confirmed(h) => core::write!(f, "confirmed_at({})", h),
+            Self::Unconfirmed => core::write!(f, "unconfirmed"),
+        }
+    }
+}
+
+impl From<Option<u32>> for TxHeight {
+    fn from(opt: Option<u32>) -> Self {
+        match opt {
+            Some(h) => Self::Confirmed(h),
+            None => Self::Unconfirmed,
+        }
+    }
+}
+
+impl From<TxHeight> for Option<u32> {
+    fn from(height: TxHeight) -> Self {
+        match height {
+            TxHeight::Confirmed(h) => Some(h),
+            TxHeight::Unconfirmed => None,
+        }
+    }
+}
+
+impl crate::sparse_chain::ChainPosition for TxHeight {
+    fn height(&self) -> TxHeight {
+        *self
+    }
+
+    fn max_ord_of_height(height: TxHeight) -> Self {
+        height
+    }
+
+    fn min_ord_of_height(height: TxHeight) -> Self {
+        height
+    }
+}
+
+impl TxHeight {
    pub fn is_confirmed(&self) -> bool {
        matches!(self, Self::Confirmed(_))
    }
 }

-impl<A: Clone> ChainPosition<&A> {
-    /// Maps a [`ChainPosition<&A>`] into a [`ChainPosition<A>`] by cloning the contents.
-    pub fn cloned(self) -> ChainPosition<A> {
-        match self {
-            ChainPosition::Confirmed(a) => ChainPosition::Confirmed(a.clone()),
-            ChainPosition::Unconfirmed(last_seen) => ChainPosition::Unconfirmed(last_seen),
-        }
-    }
-}
-
-impl<A: Anchor> ChainPosition<A> {
-    /// Determines the upper bound of the confirmation height.
-    pub fn confirmation_height_upper_bound(&self) -> Option<u32> {
-        match self {
-            ChainPosition::Confirmed(a) => Some(a.confirmation_height_upper_bound()),
-            ChainPosition::Unconfirmed(_) => None,
-        }
-    }
-}
-
 /// Block height and timestamp at which a transaction is confirmed.
 #[derive(Debug, Clone, PartialEq, Eq, Copy, PartialOrd, Ord, core::hash::Hash)]
 #[cfg_attr(
@@ -48,49 +78,47 @@ impl<A: Anchor> ChainPosition<A> {
    serde(crate = "serde_crate")
 )]
 pub enum ConfirmationTime {
-    /// The transaction is confirmed
-    Confirmed {
-        /// Confirmation height.
-        height: u32,
-        /// Confirmation time in unix seconds.
-        time: u64,
-    },
-    /// The transaction is unconfirmed
-    Unconfirmed {
-        /// The last-seen timestamp in unix seconds.
-        last_seen: u64,
-    },
+    Confirmed { height: u32, time: u64 },
+    Unconfirmed,
+}
+
+impl sparse_chain::ChainPosition for ConfirmationTime {
+    fn height(&self) -> TxHeight {
+        match self {
+            ConfirmationTime::Confirmed { height, .. } => TxHeight::Confirmed(*height),
+            ConfirmationTime::Unconfirmed => TxHeight::Unconfirmed,
+        }
+    }
+
+    fn max_ord_of_height(height: TxHeight) -> Self {
+        match height {
+            TxHeight::Confirmed(height) => Self::Confirmed {
+                height,
+                time: u64::MAX,
+            },
+            TxHeight::Unconfirmed => Self::Unconfirmed,
+        }
+    }
+
+    fn min_ord_of_height(height: TxHeight) -> Self {
+        match height {
+            TxHeight::Confirmed(height) => Self::Confirmed {
+                height,
+                time: u64::MIN,
+            },
+            TxHeight::Unconfirmed => Self::Unconfirmed,
+        }
+    }
 }

 impl ConfirmationTime {
-    /// Construct an unconfirmed variant using the given `last_seen` time in unix seconds.
-    pub fn unconfirmed(last_seen: u64) -> Self {
-        Self::Unconfirmed { last_seen }
-    }
-
-    /// Returns whether [`ConfirmationTime`] is the confirmed variant.
    pub fn is_confirmed(&self) -> bool {
        matches!(self, Self::Confirmed { .. })
    }
 }

-impl From<ChainPosition<ConfirmationTimeHeightAnchor>> for ConfirmationTime {
-    fn from(observed_as: ChainPosition<ConfirmationTimeHeightAnchor>) -> Self {
-        match observed_as {
-            ChainPosition::Confirmed(a) => Self::Confirmed {
-                height: a.confirmation_height,
-                time: a.confirmation_time,
-            },
-            ChainPosition::Unconfirmed(last_seen) => Self::Unconfirmed { last_seen },
-        }
-    }
-}
-
 /// A reference to a block in the canonical chain.
-///
-/// `BlockId` implements [`Anchor`]. When a transaction is anchored to `BlockId`, the confirmation
-/// block and anchor block are the same block.
-#[derive(Debug, Clone, PartialEq, Eq, Copy, PartialOrd, Ord, core::hash::Hash)]
+#[derive(Debug, Clone, PartialEq, Eq, Copy, PartialOrd, Ord)]
 #[cfg_attr(
    feature = "serde",
    derive(serde::Deserialize, serde::Serialize),
@@ -103,23 +131,11 @@ pub struct BlockId {
    pub hash: BlockHash,
 }

-impl Anchor for BlockId {
-    fn anchor_block(&self) -> Self {
-        *self
-    }
-}
-
-impl AnchorFromBlockPosition for BlockId {
-    fn from_block_position(_block: &bitcoin::Block, block_id: BlockId, _tx_pos: usize) -> Self {
-        block_id
-    }
-}
-
 impl Default for BlockId {
    fn default() -> Self {
        Self {
            height: Default::default(),
-            hash: BlockHash::all_zeros(),
+            hash: BlockHash::from_inner([0u8; 32]),
        }
    }
 }
@@ -145,119 +161,51 @@ impl From<(&u32, &BlockHash)> for BlockId {
    }
 }

-/// An [`Anchor`] implementation that also records the exact confirmation height of the transaction.
-///
-/// Note that the confirmation block and the anchor block can be different here.
-///
-/// Refer to [`Anchor`] for more details.
-#[derive(Debug, Default, Clone, PartialEq, Eq, Copy, PartialOrd, Ord, core::hash::Hash)]
-#[cfg_attr(
-    feature = "serde",
-    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde_crate")
-)]
-pub struct ConfirmationHeightAnchor {
-    /// The exact confirmation height of the transaction.
-    ///
-    /// It is assumed that this value is never larger than the height of the anchor block.
-    pub confirmation_height: u32,
-    /// The anchor block.
-    pub anchor_block: BlockId,
-}
-
-impl Anchor for ConfirmationHeightAnchor {
-    fn anchor_block(&self) -> BlockId {
-        self.anchor_block
-    }
-
-    fn confirmation_height_upper_bound(&self) -> u32 {
-        self.confirmation_height
-    }
-}
-
-impl AnchorFromBlockPosition for ConfirmationHeightAnchor {
-    fn from_block_position(_block: &bitcoin::Block, block_id: BlockId, _tx_pos: usize) -> Self {
-        Self {
-            anchor_block: block_id,
-            confirmation_height: block_id.height,
-        }
-    }
-}
-
-/// An [`Anchor`] implementation that also records the exact confirmation time and height of the
-/// transaction.
-///
-/// Note that the confirmation block and the anchor block can be different here.
-///
-/// Refer to [`Anchor`] for more details.
-#[derive(Debug, Default, Clone, PartialEq, Eq, Copy, PartialOrd, Ord, core::hash::Hash)]
-#[cfg_attr(
-    feature = "serde",
-    derive(serde::Deserialize, serde::Serialize),
-    serde(crate = "serde_crate")
-)]
-pub struct ConfirmationTimeHeightAnchor {
-    /// The confirmation height of the transaction being anchored.
-    pub confirmation_height: u32,
-    /// The confirmation time of the transaction being anchored.
-    pub confirmation_time: u64,
-    /// The anchor block.
-    pub anchor_block: BlockId,
-}
-
-impl Anchor for ConfirmationTimeHeightAnchor {
-    fn anchor_block(&self) -> BlockId {
-        self.anchor_block
-    }
-
-    fn confirmation_height_upper_bound(&self) -> u32 {
-        self.confirmation_height
-    }
-}
-
-impl AnchorFromBlockPosition for ConfirmationTimeHeightAnchor {
-    fn from_block_position(block: &bitcoin::Block, block_id: BlockId, _tx_pos: usize) -> Self {
-        Self {
-            anchor_block: block_id,
-            confirmation_height: block_id.height,
-            confirmation_time: block.header.time as _,
-        }
-    }
-}
-
 /// A `TxOut` with as much data as we can retrieve about it
-#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
-pub struct FullTxOut<A> {
-    /// The position of the transaction in `outpoint` in the overall chain.
-    pub chain_position: ChainPosition<A>,
+#[derive(Debug, Clone, PartialEq)]
+pub struct FullTxOut<I> {
    /// The location of the `TxOut`.
    pub outpoint: OutPoint,
    /// The `TxOut`.
    pub txout: TxOut,
+    /// The position of the transaction in `outpoint` in the overall chain.
+    pub chain_position: I,
    /// The txid and chain position of the transaction (if any) that has spent this output.
-    pub spent_by: Option<(ChainPosition<A>, Txid)>,
+    pub spent_by: Option<(I, Txid)>,
    /// Whether this output is on a coinbase transaction.
    pub is_on_coinbase: bool,
 }

-impl<A: Anchor> FullTxOut<A> {
-    /// Whether the `txout` is considered mature.
+impl<I: ChainPosition> FullTxOut<I> {
+    /// Whether the utxo is/was/will be spendable at `height`.
    ///
-    /// Depending on the implementation of [`confirmation_height_upper_bound`] in [`Anchor`], this
-    /// method may return false-negatives. In other words, interpreted confirmation count may be
-    /// less than the actual value.
-    ///
-    /// [`confirmation_height_upper_bound`]: Anchor::confirmation_height_upper_bound
-    pub fn is_mature(&self, tip: u32) -> bool {
+    /// It is spendable if it is not an immature coinbase output and no spending tx has been
+    /// confirmed by that height.
+    pub fn is_spendable_at(&self, height: u32) -> bool {
+        if !self.is_mature(height) {
+            return false;
+        }
+
+        if self.chain_position.height() > TxHeight::Confirmed(height) {
+            return false;
+        }
+
+        match &self.spent_by {
+            Some((spending_height, _)) => spending_height.height() > TxHeight::Confirmed(height),
+            None => true,
+        }
+    }
+
+    pub fn is_mature(&self, height: u32) -> bool {
        if self.is_on_coinbase {
-            let tx_height = match &self.chain_position {
-                ChainPosition::Confirmed(anchor) => anchor.confirmation_height_upper_bound(),
-                ChainPosition::Unconfirmed(_) => {
+            let tx_height = match self.chain_position.height() {
+                TxHeight::Confirmed(tx_height) => tx_height,
+                TxHeight::Unconfirmed => {
                    debug_assert!(false, "coinbase tx can never be unconfirmed");
                    return false;
                }
            };
-            let age = tip.saturating_sub(tx_height);
+            let age = height.saturating_sub(tx_height);
            if age + 1 < COINBASE_MATURITY {
                return false;
            }
@@ -265,68 +213,6 @@ impl<A: Anchor> FullTxOut<A> {

        true
    }
-
-    /// Whether the utxo is/was/will be spendable with chain `tip`.
-    ///
-    /// This method does not take into account the lock time.
-    ///
-    /// Depending on the implementation of [`confirmation_height_upper_bound`] in [`Anchor`], this
-    /// method may return false-negatives. In other words, interpreted confirmation count may be
-    /// less than the actual value.
-    ///
-    /// [`confirmation_height_upper_bound`]: Anchor::confirmation_height_upper_bound
-    pub fn is_confirmed_and_spendable(&self, tip: u32) -> bool {
-        if !self.is_mature(tip) {
-            return false;
-        }
-
-        let confirmation_height = match &self.chain_position {
-            ChainPosition::Confirmed(anchor) => anchor.confirmation_height_upper_bound(),
-            ChainPosition::Unconfirmed(_) => return false,
-        };
-        if confirmation_height > tip {
-            return false;
-        }
-
-        // if the spending tx is confirmed within tip height, the txout is no longer spendable
-        if let Some((ChainPosition::Confirmed(spending_anchor), _)) = &self.spent_by {
-            if spending_anchor.anchor_block().height <= tip {
-                return false;
-            }
-        }
-
-        true
-    }
 }

-#[cfg(test)]
-mod test {
-    use super::*;
-
-    #[test]
-    fn chain_position_ord() {
-        let unconf1 = ChainPosition::<ConfirmationHeightAnchor>::Unconfirmed(10);
-        let unconf2 = ChainPosition::<ConfirmationHeightAnchor>::Unconfirmed(20);
-        let conf1 = ChainPosition::Confirmed(ConfirmationHeightAnchor {
-            confirmation_height: 9,
-            anchor_block: BlockId {
-                height: 20,
-                ..Default::default()
-            },
-        });
-        let conf2 = ChainPosition::Confirmed(ConfirmationHeightAnchor {
-            confirmation_height: 12,
-            anchor_block: BlockId {
-                height: 15,
-                ..Default::default()
-            },
-        });
-
-        assert!(unconf2 > unconf1, "higher last_seen means higher ord");
-        assert!(unconf1 > conf1, "unconfirmed is higher ord than confirmed");
-        assert!(
-            conf2 > conf1,
-            "confirmation_height is higher then it should be higher ord"
-        );
-    }
-}
+// TODO: make test
--- a/crates/chain/src/chain_graph.rs
+++ b/crates/chain/src/chain_graph.rs
@@ -0,0 +1,639 @@
+//! Module for structures that combine the features of [`sparse_chain`] and [`tx_graph`].
+use crate::{
+    collections::HashSet,
+    sparse_chain::{self, ChainPosition, SparseChain},
+    tx_graph::{self, TxGraph},
+    BlockId, ForEachTxOut, FullTxOut, TxHeight,
+};
+use alloc::{string::ToString, vec::Vec};
+use bitcoin::{OutPoint, Transaction, TxOut, Txid};
+use core::fmt::Debug;
+
+/// A consistent combination of a [`SparseChain<P>`] and a [`TxGraph<T>`].
+///
+/// `SparseChain` only keeps track of transaction ids and their position in the chain, but you often
+/// want to store the full transactions as well. Additionally, you want to make sure that everything
+/// in the chain is consistent with the full transaction data. `ChainGraph` enforces these two
+/// invariants:
+///
+/// 1. Every transaction that is in the chain is also in the graph (you always have the full
+/// transaction).
+/// 2. No transactions in the chain conflict with each other, i.e., they don't double spend each
+/// other or have ancestors that double spend each other.
+///
+/// Note that the `ChainGraph` guarantees a 1:1 mapping between transactions in the `chain` and
+/// `graph` but not the other way around. Transactions may fall out of the *chain* (via re-org or
+/// mempool eviction) but will remain in the *graph*.
+#[derive(Clone, Debug, PartialEq)]
+pub struct ChainGraph<P = TxHeight> {
+    chain: SparseChain<P>,
+    graph: TxGraph,
+}
+
+impl<P> Default for ChainGraph<P> {
+    fn default() -> Self {
+        Self {
+            chain: Default::default(),
+            graph: Default::default(),
+        }
+    }
+}
+
+impl<P> AsRef<SparseChain<P>> for ChainGraph<P> {
+    fn as_ref(&self) -> &SparseChain<P> {
+        &self.chain
+    }
+}
+
+impl<P> AsRef<TxGraph> for ChainGraph<P> {
+    fn as_ref(&self) -> &TxGraph {
+        &self.graph
+    }
+}
+
+impl<P> AsRef<ChainGraph<P>> for ChainGraph<P> {
+    fn as_ref(&self) -> &ChainGraph<P> {
+        self
+    }
+}
+
+impl<P> ChainGraph<P> {
+    /// Returns a reference to the internal [`SparseChain`].
+    pub fn chain(&self) -> &SparseChain<P> {
+        &self.chain
+    }
+
+    /// Returns a reference to the internal [`TxGraph`].
+    pub fn graph(&self) -> &TxGraph {
+        &self.graph
+    }
+}
+
+impl<P> ChainGraph<P>
+where
+    P: ChainPosition,
+{
+    /// Create a new chain graph from a `chain` and a `graph`.
+    ///
+    /// There are two reasons this can return an `Err`:
+    ///
+    /// 1. There is a transaction in the `chain` that does not have its corresponding full
+    /// transaction in `graph`.
+    /// 2. The `chain` has two transactions that are allegedly in it, but they conflict in the `graph`
+    /// (so could not possibly be in the same chain).
+    pub fn new(chain: SparseChain<P>, graph: TxGraph) -> Result<Self, NewError<P>> {
+        let mut missing = HashSet::default();
+        for (pos, txid) in chain.txids() {
+            if let Some(tx) = graph.get_tx(*txid) {
+                let conflict = graph
+                    .walk_conflicts(tx, |_, txid| Some((chain.tx_position(txid)?.clone(), txid)))
+                    .next();
+                if let Some((conflict_pos, conflict)) = conflict {
+                    return Err(NewError::Conflict {
+                        a: (pos.clone(), *txid),
+                        b: (conflict_pos, conflict),
+                    });
+                }
+            } else {
+                missing.insert(*txid);
+            }
+        }
+
+        if !missing.is_empty() {
+            return Err(NewError::Missing(missing));
+        }
+
+        Ok(Self { chain, graph })
+    }
+
+    /// Take an update in the form of a [`SparseChain<P>`][`SparseChain`] and attempt to turn it
+    /// into a chain graph by filling in full transactions from `self` and from `new_txs`. This
+    /// returns a `ChainGraph<P, Cow<T>>` where the [`Cow<'a, T>`] will borrow the transaction if it
+    /// got it from `self`.
+    ///
+    /// This is useful when interacting with services like an electrum server which returns a list
+    /// of txids and heights when calling [`script_get_history`], which can easily be inserted into a
+    /// [`SparseChain<TxHeight>`][`SparseChain`]. From there, you need to figure out which full
+    /// transactions you are missing in your chain graph and form `new_txs`. You then use
+    /// `inflate_update` to turn this into an update `ChainGraph<P, Cow<Transaction>>` and finally
+    /// use [`determine_changeset`] to generate the changeset from it.
+    ///
+    /// [`SparseChain`]: crate::sparse_chain::SparseChain
+    /// [`Cow<'a, T>`]: std::borrow::Cow
+    /// [`script_get_history`]: https://docs.rs/electrum-client/latest/electrum_client/trait.ElectrumApi.html#tymethod.script_get_history
+    /// [`determine_changeset`]: Self::determine_changeset
+    pub fn inflate_update(
+        &self,
+        update: SparseChain<P>,
+        new_txs: impl IntoIterator<Item = Transaction>,
+    ) -> Result<ChainGraph<P>, NewError<P>> {
+        let mut inflated_chain = SparseChain::default();
+        let mut inflated_graph = TxGraph::default();
+
+        for (height, hash) in update.checkpoints().clone().into_iter() {
+            let _ = inflated_chain
+                .insert_checkpoint(BlockId { height, hash })
+                .expect("must insert");
+        }
+
+        // [TODO] @evanlinjin: These need better comments
+        // - copy transactions that have changed positions into the graph
+        // - add new transactions to an inflated chain
+        for (pos, txid) in update.txids() {
+            match self.chain.tx_position(*txid) {
+                Some(original_pos) => {
+                    if original_pos != pos {
+                        let tx = self
+                            .graph
+                            .get_tx(*txid)
+                            .expect("tx must exist as it is referenced in sparsechain")
+                            .clone();
+                        let _ = inflated_chain
+                            .insert_tx(*txid, pos.clone())
+                            .expect("must insert since this was already in update");
+                        let _ = inflated_graph.insert_tx(tx);
+                    }
+                }
+                None => {
+                    let _ = inflated_chain
+                        .insert_tx(*txid, pos.clone())
+                        .expect("must insert since this was already in update");
+                }
+            }
+        }
+
+        for tx in new_txs {
+            let _ = inflated_graph.insert_tx(tx);
+        }
+
+        ChainGraph::new(inflated_chain, inflated_graph)
+    }
+
+    /// Gets the checkpoint limit.
+    ///
+    /// Refer to [`SparseChain::checkpoint_limit`] for more.
+    pub fn checkpoint_limit(&self) -> Option<usize> {
+        self.chain.checkpoint_limit()
+    }
+
+    /// Sets the checkpoint limit.
+    ///
+    /// Refer to [`SparseChain::set_checkpoint_limit`] for more.
+    pub fn set_checkpoint_limit(&mut self, limit: Option<usize>) {
+        self.chain.set_checkpoint_limit(limit)
+    }
+
+    /// Determines the changes required to invalidate checkpoints `from_height` (inclusive) and
+    /// above. Displaced transactions will have their positions moved to [`TxHeight::Unconfirmed`].
+    pub fn invalidate_checkpoints_preview(&self, from_height: u32) -> ChangeSet<P> {
+        ChangeSet {
+            chain: self.chain.invalidate_checkpoints_preview(from_height),
+            ..Default::default()
+        }
+    }
+
+    /// Invalidate checkpoints `from_height` (inclusive) and above. Displaced transactions will be
+    /// re-positioned to [`TxHeight::Unconfirmed`].
+    ///
+    /// This is equivalent to calling [`Self::invalidate_checkpoints_preview`] and
+    /// [`Self::apply_changeset`] in sequence.
+    pub fn invalidate_checkpoints(&mut self, from_height: u32) -> ChangeSet<P>
+    where
+        ChangeSet<P>: Clone,
+    {
+        let changeset = self.invalidate_checkpoints_preview(from_height);
+        self.apply_changeset(changeset.clone());
+        changeset
+    }
+
+    /// Get a transaction currently in the underlying [`SparseChain`].
+    ///
+    /// This does not necessarily mean that it is *confirmed* in the blockchain; it might just be in
+    /// the unconfirmed transaction list within the [`SparseChain`].
+    pub fn get_tx_in_chain(&self, txid: Txid) -> Option<(&P, &Transaction)> {
+        let position = self.chain.tx_position(txid)?;
+        let full_tx = self.graph.get_tx(txid).expect("must exist");
+        Some((position, full_tx))
+    }
+
+    /// Determines the changes required to insert a transaction into the inner [`ChainGraph`] and
+    /// [`SparseChain`] at the given `position`.
+    ///
+    /// If inserting it into the chain `position` will result in conflicts, the returned
+    /// [`ChangeSet`] should evict conflicting transactions.
+    pub fn insert_tx_preview(
+        &self,
+        tx: Transaction,
+        pos: P,
+    ) -> Result<ChangeSet<P>, InsertTxError<P>> {
+        let mut changeset = ChangeSet {
+            chain: self.chain.insert_tx_preview(tx.txid(), pos)?,
+            graph: self.graph.insert_tx_preview(tx),
+        };
+        self.fix_conflicts(&mut changeset)?;
+        Ok(changeset)
+    }
+
+    /// Inserts [`Transaction`] at the given chain position.
+    ///
+    /// This is equivalent to calling [`Self::insert_tx_preview`] and [`Self::apply_changeset`] in
+    /// sequence.
+    pub fn insert_tx(&mut self, tx: Transaction, pos: P) -> Result<ChangeSet<P>, InsertTxError<P>> {
+        let changeset = self.insert_tx_preview(tx, pos)?;
+        self.apply_changeset(changeset.clone());
+        Ok(changeset)
+    }
+
+    /// Determines the changes required to insert a [`TxOut`] into the internal [`TxGraph`].
+    pub fn insert_txout_preview(&self, outpoint: OutPoint, txout: TxOut) -> ChangeSet<P> {
+        ChangeSet {
+            chain: Default::default(),
+            graph: self.graph.insert_txout_preview(outpoint, txout),
+        }
+    }
+
+    /// Inserts a [`TxOut`] into the internal [`TxGraph`].
+    ///
+    /// This is equivalent to calling [`Self::insert_txout_preview`] and [`Self::apply_changeset`]
+    /// in sequence.
+    pub fn insert_txout(&mut self, outpoint: OutPoint, txout: TxOut) -> ChangeSet<P> {
+        let changeset = self.insert_txout_preview(outpoint, txout);
+        self.apply_changeset(changeset.clone());
+        changeset
+    }
+
+    /// Determines the changes required to insert a `block_id` (a height and block hash) into the
+    /// chain.
+    ///
+    /// If a checkpoint with a different hash already exists at that height, this will return an error.
+    pub fn insert_checkpoint_preview(
+        &self,
+        block_id: BlockId,
+    ) -> Result<ChangeSet<P>, InsertCheckpointError> {
+        self.chain
+            .insert_checkpoint_preview(block_id)
+            .map(|chain_changeset| ChangeSet {
+                chain: chain_changeset,
+                ..Default::default()
+            })
+    }
+
+    /// Inserts checkpoint into [`Self`].
+    ///
+    /// This is equivalent to calling [`Self::insert_checkpoint_preview`] and
+    /// [`Self::apply_changeset`] in sequence.
+    pub fn insert_checkpoint(
+        &mut self,
+        block_id: BlockId,
+    ) -> Result<ChangeSet<P>, InsertCheckpointError> {
+        let changeset = self.insert_checkpoint_preview(block_id)?;
+        self.apply_changeset(changeset.clone());
+        Ok(changeset)
+    }
+
+    /// Calculates the difference between self and `update` in the form of a [`ChangeSet`].
+    pub fn determine_changeset(
+        &self,
+        update: &ChainGraph<P>,
+    ) -> Result<ChangeSet<P>, UpdateError<P>> {
+        let chain_changeset = self
+            .chain
+            .determine_changeset(&update.chain)
+            .map_err(UpdateError::Chain)?;
+
+        let mut changeset = ChangeSet {
+            chain: chain_changeset,
+            graph: self.graph.determine_additions(&update.graph),
+        };
+
+        self.fix_conflicts(&mut changeset)?;
+        Ok(changeset)
+    }
+
+    /// Given a transaction, return an iterator of `txid`s that conflict with it (spends at least
+    /// one of the same inputs). This iterator includes all descendants of conflicting transactions.
+    ///
+    /// This method only returns conflicts that exist in the [`SparseChain`] as transactions that
+    /// are not included in [`SparseChain`] are already considered as evicted.
+    pub fn tx_conflicts_in_chain<'a>(
+        &'a self,
+        tx: &'a Transaction,
+    ) -> impl Iterator<Item = (&'a P, Txid)> + 'a {
+        self.graph.walk_conflicts(tx, move |_, conflict_txid| {
+            self.chain
+                .tx_position(conflict_txid)
+                .map(|conflict_pos| (conflict_pos, conflict_txid))
+        })
+    }
+
+    /// Fix changeset conflicts.
+    ///
+    /// **WARNING:** If there are any missing full txs, conflict resolution will not be complete. In
+    /// debug mode, this will result in panic.
+    fn fix_conflicts(&self, changeset: &mut ChangeSet<P>) -> Result<(), UnresolvableConflict<P>> {
+        let mut chain_conflicts = vec![];
+
+        for (&txid, pos_change) in &changeset.chain.txids {
+            let pos = match pos_change {
+                Some(pos) => {
+                    // Ignore txs that are still in the chain -- we only care about new ones
+                    if self.chain.tx_position(txid).is_some() {
+                        continue;
+                    }
+                    pos
+                }
+                // Ignore txids that are being deleted by the change (they can't conflict)
+                None => continue,
+            };
+
+            let mut full_tx = self.graph.get_tx(txid);
+
+            if full_tx.is_none() {
+                full_tx = changeset.graph.tx.iter().find(|tx| tx.txid() == txid)
+            }
+
+            debug_assert!(full_tx.is_some(), "should have full tx at this point");
+
+            let full_tx = match full_tx {
+                Some(full_tx) => full_tx,
+                None => continue,
+            };
+
+            for (conflict_pos, conflict_txid) in self.tx_conflicts_in_chain(full_tx) {
+                chain_conflicts.push((pos.clone(), txid, conflict_pos, conflict_txid))
+            }
+        }
+
+        for (update_pos, update_txid, conflicting_pos, conflicting_txid) in chain_conflicts {
+            // We have found a tx that conflicts with our update txid. Only allow this when the
+            // conflicting tx will be positioned as "unconfirmed" after the update is applied.
+            // If so, we will modify the changeset to evict the conflicting txid.
+
+            // determine the position of the conflicting txid after the current changeset is applied
+            let conflicting_new_pos = changeset
+                .chain
+                .txids
+                .get(&conflicting_txid)
+                .map(Option::as_ref)
+                .unwrap_or(Some(conflicting_pos));
+
+            match conflicting_new_pos {
+                None => {
+                    // conflicting txid will be deleted, can ignore
+                }
+                Some(existing_new_pos) => match existing_new_pos.height() {
+                    TxHeight::Confirmed(_) => {
+                        // the new position of the conflicting tx is "confirmed", therefore cannot be
+                        // evicted, return error
+                        return Err(UnresolvableConflict {
+                            already_confirmed_tx: (conflicting_pos.clone(), conflicting_txid),
+                            update_tx: (update_pos, update_txid),
+                        });
+                    }
+                    TxHeight::Unconfirmed => {
+                        // the new position of the conflicting tx is "unconfirmed", therefore it can
+                        // be evicted
+                        changeset.chain.txids.insert(conflicting_txid, None);
+                    }
+                },
+            };
+        }
+
+        Ok(())
+    }
+
+    /// Applies `changeset` to `self`.
+    ///
+    /// **Warning** this method assumes that the changeset is correctly formed. If it is not, the
+    /// chain graph may behave incorrectly in the future and panic unexpectedly.
+    pub fn apply_changeset(&mut self, changeset: ChangeSet<P>) {
+        self.chain.apply_changeset(changeset.chain);
+        self.graph.apply_additions(changeset.graph);
+    }
+
+    /// Applies the `update` chain graph. Note this is shorthand for calling
+    /// [`Self::determine_changeset()`] and [`Self::apply_changeset()`] in sequence.
+    pub fn apply_update(&mut self, update: ChainGraph<P>) -> Result<ChangeSet<P>, UpdateError<P>> {
+        let changeset = self.determine_changeset(&update)?;
+        self.apply_changeset(changeset.clone());
+        Ok(changeset)
+    }
+
+    /// Get the full transaction output at an outpoint if it exists in the chain and the graph.
+    pub fn full_txout(&self, outpoint: OutPoint) -> Option<FullTxOut<P>> {
+        self.chain.full_txout(&self.graph, outpoint)
+    }
+
+    /// Iterate over the full transactions and their position in the chain ordered by their position
+    /// in ascending order.
+    pub fn transactions_in_chain(&self) -> impl DoubleEndedIterator<Item = (&P, &Transaction)> {
+        self.chain
+            .txids()
+            .map(move |(pos, txid)| (pos, self.graph.get_tx(*txid).expect("must exist")))
+    }
+
+    /// Find the transaction in the chain that spends `outpoint`.
+    ///
+    /// This uses the input/output relationships in the internal `graph`. Note that the transaction
+    /// which includes `outpoint` does not need to be in the `graph` or the `chain` for this to
+    /// return `Some(_)`.
+    pub fn spent_by(&self, outpoint: OutPoint) -> Option<(&P, Txid)> {
+        self.chain.spent_by(&self.graph, outpoint)
+    }
+
+    /// Whether the chain graph contains any data whatsoever.
+    pub fn is_empty(&self) -> bool {
+        self.chain.is_empty() && self.graph.is_empty()
+    }
+}
+
+/// Represents changes to [`ChainGraph`].
+///
+/// This is essentially a combination of [`sparse_chain::ChangeSet`] and [`tx_graph::Additions`].
+#[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(
+    feature = "serde",
+    derive(serde::Deserialize, serde::Serialize),
+    serde(
+        crate = "serde_crate",
+        bound(
+            deserialize = "P: serde::Deserialize<'de>",
+            serialize = "P: serde::Serialize"
+        )
+    )
+)]
+#[must_use]
+pub struct ChangeSet<P> {
+    pub chain: sparse_chain::ChangeSet<P>,
+    pub graph: tx_graph::Additions,
+}
+
+impl<P> ChangeSet<P> {
+    /// Returns `true` if this [`ChangeSet`] records no changes.
+    pub fn is_empty(&self) -> bool {
+        self.chain.is_empty() && self.graph.is_empty()
+    }
+
+    /// Returns `true` if this [`ChangeSet`] contains transaction evictions.
+    pub fn contains_eviction(&self) -> bool {
+        self.chain
+            .txids
+            .iter()
+            .any(|(_, new_pos)| new_pos.is_none())
+    }
+
+    /// Appends the changes in `other` into self such that applying `self` afterward has the same
+    /// effect as sequentially applying the original `self` and `other`.
+    pub fn append(&mut self, other: ChangeSet<P>)
+    where
+        P: ChainPosition,
+    {
+        self.chain.append(other.chain);
+        self.graph.append(other.graph);
+    }
+}
+
+impl<P> Default for ChangeSet<P> {
+    fn default() -> Self {
+        Self {
+            chain: Default::default(),
+            graph: Default::default(),
+        }
+    }
+}
+
+impl<P> ForEachTxOut for ChainGraph<P> {
+    fn for_each_txout(&self, f: impl FnMut((OutPoint, &TxOut))) {
+        self.graph.for_each_txout(f)
+    }
+}
+
+impl<P> ForEachTxOut for ChangeSet<P> {
+    fn for_each_txout(&self, f: impl FnMut((OutPoint, &TxOut))) {
+        self.graph.for_each_txout(f)
+    }
+}
+
+/// Error that may occur when calling [`ChainGraph::new`].
+#[derive(Clone, Debug, PartialEq)]
+pub enum NewError<P> {
+    /// Two transactions within the sparse chain conflicted with each other
+    Conflict { a: (P, Txid), b: (P, Txid) },
+    /// One or more transactions in the chain were not in the graph
+    Missing(HashSet<Txid>),
+}
+
+impl<P: core::fmt::Debug> core::fmt::Display for NewError<P> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        match self {
+            NewError::Conflict { a, b } => write!(
+                f,
+                "Unable to inflate sparse chain to chain graph since transactions {:?} and {:?}",
+                a, b
+            ),
+            NewError::Missing(missing) => write!(
+                f,
+                "missing full transactions for {}",
+                missing
+                    .iter()
+                    .map(|txid| txid.to_string())
+                    .collect::<Vec<_>>()
+                    .join(", ")
+            ),
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl<P: core::fmt::Debug> std::error::Error for NewError<P> {}
+
+/// Error that may occur when inserting a transaction.
+///
+/// Refer to [`ChainGraph::insert_tx_preview`] and [`ChainGraph::insert_tx`].
+#[derive(Clone, Debug, PartialEq)]
+pub enum InsertTxError<P> {
+    Chain(sparse_chain::InsertTxError<P>),
+    UnresolvableConflict(UnresolvableConflict<P>),
+}
+
+impl<P: core::fmt::Debug> core::fmt::Display for InsertTxError<P> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        match self {
+            InsertTxError::Chain(inner) => core::fmt::Display::fmt(inner, f),
+            InsertTxError::UnresolvableConflict(inner) => core::fmt::Display::fmt(inner, f),
+        }
+    }
+}
+
+impl<P> From<sparse_chain::InsertTxError<P>> for InsertTxError<P> {
+    fn from(inner: sparse_chain::InsertTxError<P>) -> Self {
+        Self::Chain(inner)
+    }
+}
+
+#[cfg(feature = "std")]
+impl<P: core::fmt::Debug> std::error::Error for InsertTxError<P> {}
+
+/// A nice alias of [`sparse_chain::InsertCheckpointError`].
+pub type InsertCheckpointError = sparse_chain::InsertCheckpointError;
+
+/// Represents an update failure.
+#[derive(Clone, Debug, PartialEq)]
+pub enum UpdateError<P> {
+    /// The update chain was inconsistent with the existing chain
+    Chain(sparse_chain::UpdateError<P>),
+    /// A transaction in the update spent the same input as an already confirmed transaction
+    UnresolvableConflict(UnresolvableConflict<P>),
+}
+
+impl<P: core::fmt::Debug> core::fmt::Display for UpdateError<P> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        match self {
+            UpdateError::Chain(inner) => core::fmt::Display::fmt(inner, f),
+            UpdateError::UnresolvableConflict(inner) => core::fmt::Display::fmt(inner, f),
+        }
+    }
+}
+
+impl<P> From<sparse_chain::UpdateError<P>> for UpdateError<P> {
+    fn from(inner: sparse_chain::UpdateError<P>) -> Self {
+        Self::Chain(inner)
+    }
+}
+
+#[cfg(feature = "std")]
+impl<P: core::fmt::Debug> std::error::Error for UpdateError<P> {}
+
+/// Represents an unresolvable conflict between an update's transaction and an
+/// already-confirmed transaction.
+#[derive(Clone, Debug, PartialEq)]
+pub struct UnresolvableConflict<P> {
+    pub already_confirmed_tx: (P, Txid),
+    pub update_tx: (P, Txid),
+}
+
+impl<P: core::fmt::Debug> core::fmt::Display for UnresolvableConflict<P> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        let Self {
+            already_confirmed_tx,
+            update_tx,
+        } = self;
+        write!(f, "update transaction {} at height {:?} conflicts with an already confirmed transaction {} at height {:?}",
+            update_tx.1, update_tx.0, already_confirmed_tx.1, already_confirmed_tx.0)
+    }
+}
+
+impl<P> From<UnresolvableConflict<P>> for UpdateError<P> {
+    fn from(inner: UnresolvableConflict<P>) -> Self {
+        Self::UnresolvableConflict(inner)
+    }
+}
+
+impl<P> From<UnresolvableConflict<P>> for InsertTxError<P> {
+    fn from(inner: UnresolvableConflict<P>) -> Self {
+        Self::UnresolvableConflict(inner)
+    }
+}
+
+#[cfg(feature = "std")]
+impl<P: core::fmt::Debug> std::error::Error for UnresolvableConflict<P> {}
--- a/crates/chain/src/chain_oracle.rs
+++ b/crates/chain/src/chain_oracle.rs
@@ -1,25 +0,0 @@
-use crate::BlockId;
-
-/// Represents a service that tracks the blockchain.
-///
-/// The main method is [`is_block_in_chain`] which determines whether a given block of [`BlockId`]
-/// is an ancestor of the `chain_tip`.
-///
-/// [`is_block_in_chain`]: Self::is_block_in_chain
-pub trait ChainOracle {
-    /// Error type.
-    type Error: core::fmt::Debug;
-
-    /// Determines whether `block` of [`BlockId`] exists as an ancestor of `chain_tip`.
-    ///
-    /// If `None` is returned, it means the implementation cannot determine whether `block` exists
-    /// under `chain_tip`.
-    fn is_block_in_chain(
-        &self,
-        block: BlockId,
-        chain_tip: BlockId,
-    ) -> Result<Option<bool>, Self::Error>;
-
-    /// Get the best chain's chain tip.
-    fn get_chain_tip(&self) -> Result<BlockId, Self::Error>;
-}
--- a/crates/chain/src/descriptor_ext.rs
+++ b/crates/chain/src/descriptor_ext.rs
@@ -3,14 +3,12 @@ use crate::miniscript::{Descriptor, DescriptorPublicKey};
 /// A trait to extend the functionality of a miniscript descriptor.
 pub trait DescriptorExt {
    /// Returns the minimum value (in satoshis) at which an output is broadcastable.
-    /// Panics if the descriptor wildcard is hardened.
    fn dust_value(&self) -> u64;
 }

 impl DescriptorExt for Descriptor<DescriptorPublicKey> {
    fn dust_value(&self) -> u64 {
        self.at_derivation_index(0)
-            .expect("descriptor can't have hardened derivation")
            .script_pubkey()
            .dust_value()
            .to_sat()
--- a/crates/chain/src/indexed_tx_graph.rs
+++ b/crates/chain/src/indexed_tx_graph.rs
@@ -1,354 +0,0 @@
-//! Contains the [`IndexedTxGraph`] and associated types. Refer to the
-//! [`IndexedTxGraph`] documentation for more.
-use alloc::vec::Vec;
-use bitcoin::{Block, OutPoint, Transaction, TxOut, Txid};
-
-use crate::{
-    keychain,
-    tx_graph::{self, TxGraph},
-    Anchor, AnchorFromBlockPosition, Append, BlockId,
-};
-
-/// The [`IndexedTxGraph`] combines a [`TxGraph`] and an [`Indexer`] implementation.
-///
-/// It ensures that [`TxGraph`] and [`Indexer`] are updated atomically.
-#[derive(Debug)]
-pub struct IndexedTxGraph<A, I> {
-    /// Transaction index.
-    pub index: I,
-    graph: TxGraph<A>,
-}
-
-impl<A, I: Default> Default for IndexedTxGraph<A, I> {
-    fn default() -> Self {
-        Self {
-            graph: Default::default(),
-            index: Default::default(),
-        }
-    }
-}
-
-impl<A, I> IndexedTxGraph<A, I> {
-    /// Construct a new [`IndexedTxGraph`] with a given `index`.
-    pub fn new(index: I) -> Self {
-        Self {
-            index,
-            graph: TxGraph::default(),
-        }
-    }
-
-    /// Get a reference of the internal transaction graph.
-    pub fn graph(&self) -> &TxGraph<A> {
-        &self.graph
-    }
-}
-
-impl<A: Anchor, I: Indexer> IndexedTxGraph<A, I> {
-    /// Applies the [`ChangeSet`] to the [`IndexedTxGraph`].
-    pub fn apply_changeset(&mut self, changeset: ChangeSet<A, I::ChangeSet>) {
-        self.index.apply_changeset(changeset.indexer);
-
-        for tx in &changeset.graph.txs {
-            self.index.index_tx(tx);
-        }
-        for (&outpoint, txout) in &changeset.graph.txouts {
-            self.index.index_txout(outpoint, txout);
-        }
-
-        self.graph.apply_changeset(changeset.graph);
-    }
-
-    /// Determines the [`ChangeSet`] between `self` and an empty [`IndexedTxGraph`].
-    pub fn initial_changeset(&self) -> ChangeSet<A, I::ChangeSet> {
-        let graph = self.graph.initial_changeset();
-        let indexer = self.index.initial_changeset();
-        ChangeSet { graph, indexer }
-    }
-}
-
-impl<A: Anchor, I: Indexer> IndexedTxGraph<A, I>
-where
-    I::ChangeSet: Default + Append,
-{
-    fn index_tx_graph_changeset(
-        &mut self,
-        tx_graph_changeset: &tx_graph::ChangeSet<A>,
-    ) -> I::ChangeSet {
-        let mut changeset = I::ChangeSet::default();
-        for added_tx in &tx_graph_changeset.txs {
-            changeset.append(self.index.index_tx(added_tx));
-        }
-        for (&added_outpoint, added_txout) in &tx_graph_changeset.txouts {
-            changeset.append(self.index.index_txout(added_outpoint, added_txout));
-        }
-        changeset
-    }
-
-    /// Apply an `update` directly.
-    ///
-    /// `update` is a [`TxGraph<A>`] and the resultant changes is returned as [`ChangeSet`].
-    pub fn apply_update(&mut self, update: TxGraph<A>) -> ChangeSet<A, I::ChangeSet> {
-        let graph = self.graph.apply_update(update);
-        let indexer = self.index_tx_graph_changeset(&graph);
-        ChangeSet { graph, indexer }
-    }
-
-    /// Insert a floating `txout` of given `outpoint`.
-    pub fn insert_txout(&mut self, outpoint: OutPoint, txout: TxOut) -> ChangeSet<A, I::ChangeSet> {
-        let graph = self.graph.insert_txout(outpoint, txout);
-        let indexer = self.index_tx_graph_changeset(&graph);
-        ChangeSet { graph, indexer }
-    }
-
-    /// Insert and index a transaction into the graph.
-    pub fn insert_tx(&mut self, tx: Transaction) -> ChangeSet<A, I::ChangeSet> {
-        let graph = self.graph.insert_tx(tx);
-        let indexer = self.index_tx_graph_changeset(&graph);
-        ChangeSet { graph, indexer }
-    }
-
-    /// Insert an `anchor` for a given transaction.
-    pub fn insert_anchor(&mut self, txid: Txid, anchor: A) -> ChangeSet<A, I::ChangeSet> {
-        self.graph.insert_anchor(txid, anchor).into()
-    }
-
-    /// Insert a unix timestamp of when a transaction is seen in the mempool.
-    ///
-    /// This is used for transaction conflict resolution in [`TxGraph`] where the transaction with
-    /// the later last-seen is prioritized.
-    pub fn insert_seen_at(&mut self, txid: Txid, seen_at: u64) -> ChangeSet<A, I::ChangeSet> {
-        self.graph.insert_seen_at(txid, seen_at).into()
-    }
-
-    /// Batch insert transactions, filtering out those that are irrelevant.
-    ///
-    /// Relevancy is determined by the [`Indexer::is_tx_relevant`] implementation of `I`. Irrelevant
-    /// transactions in `txs` will be ignored. `txs` do not need to be in topological order.
-    pub fn batch_insert_relevant<'t>(
-        &mut self,
-        txs: impl IntoIterator<Item = (&'t Transaction, impl IntoIterator<Item = A>)>,
-    ) -> ChangeSet<A, I::ChangeSet> {
-        // The algorithm below allows for non-topologically ordered transactions by using two loops.
-        // This is achieved by:
-        // 1. insert all txs into the index. If they are irrelevant then that's fine it will just
-        //    not store anything about them.
-        // 2. decide whether to insert them into the graph depending on whether `is_tx_relevant`
-        //    returns true or not. (in a second loop).
-        let txs = txs.into_iter().collect::<Vec<_>>();
-
-        let mut indexer = I::ChangeSet::default();
-        for (tx, _) in &txs {
-            indexer.append(self.index.index_tx(tx));
-        }
-
-        let mut graph = tx_graph::ChangeSet::default();
-        for (tx, anchors) in txs {
-            if self.index.is_tx_relevant(tx) {
-                let txid = tx.txid();
-                graph.append(self.graph.insert_tx(tx.clone()));
-                for anchor in anchors {
-                    graph.append(self.graph.insert_anchor(txid, anchor));
-                }
-            }
-        }
-
-        ChangeSet { graph, indexer }
-    }
-
-    /// Batch insert unconfirmed transactions, filtering out those that are irrelevant.
-    ///
-    /// Relevancy is determined by the internal [`Indexer::is_tx_relevant`] implementation of `I`.
-    /// Irrelevant transactions in `txs` will be ignored.
-    ///
-    /// Items of `txs` are tuples containing the transaction and a *last seen* timestamp. The
-    /// *last seen* communicates when the transaction is last seen in the mempool which is used for
-    /// conflict-resolution in [`TxGraph`] (refer to [`TxGraph::insert_seen_at`] for details).
-    pub fn batch_insert_relevant_unconfirmed<'t>(
-        &mut self,
-        unconfirmed_txs: impl IntoIterator<Item = (&'t Transaction, u64)>,
-    ) -> ChangeSet<A, I::ChangeSet> {
-        // The algorithm below allows for non-topologically ordered transactions by using two loops.
-        // This is achieved by:
-        // 1. insert all txs into the index. If they are irrelevant then that's fine it will just
-        //    not store anything about them.
-        // 2. decide whether to insert them into the graph depending on whether `is_tx_relevant`
-        //    returns true or not. (in a second loop).
-        let txs = unconfirmed_txs.into_iter().collect::<Vec<_>>();
-
-        let mut indexer = I::ChangeSet::default();
-        for (tx, _) in &txs {
-            indexer.append(self.index.index_tx(tx));
-        }
-
-        let graph = self.graph.batch_insert_unconfirmed(
-            txs.into_iter()
-                .filter(|(tx, _)| self.index.is_tx_relevant(tx))
-                .map(|(tx, seen_at)| (tx.clone(), seen_at)),
-        );
-
-        ChangeSet { graph, indexer }
-    }
-
-    /// Batch insert unconfirmed transactions.
-    ///
-    /// Items of `txs` are tuples containing the transaction and a *last seen* timestamp. The
-    /// *last seen* communicates when the transaction is last seen in the mempool which is used for
-    /// conflict-resolution in [`TxGraph`] (refer to [`TxGraph::insert_seen_at`] for details).
-    ///
-    /// To filter out irrelevant transactions, use [`batch_insert_relevant_unconfirmed`] instead.
-    ///
-    /// [`batch_insert_relevant_unconfirmed`]: IndexedTxGraph::batch_insert_relevant_unconfirmed
-    pub fn batch_insert_unconfirmed(
-        &mut self,
-        txs: impl IntoIterator<Item = (Transaction, u64)>,
-    ) -> ChangeSet<A, I::ChangeSet> {
-        let graph = self.graph.batch_insert_unconfirmed(txs);
-        let indexer = self.index_tx_graph_changeset(&graph);
-        ChangeSet { graph, indexer }
-    }
-}
-
-/// Methods are available if the anchor (`A`) implements [`AnchorFromBlockPosition`].
-impl<A: Anchor, I: Indexer> IndexedTxGraph<A, I>
-where
-    I::ChangeSet: Default + Append,
-    A: AnchorFromBlockPosition,
-{
-    /// Batch insert all transactions of the given `block` of `height`, filtering out those that are
-    /// irrelevant.
-    ///
-    /// Each inserted transaction's anchor will be constructed from
-    /// [`AnchorFromBlockPosition::from_block_position`].
-    ///
-    /// Relevancy is determined by the internal [`Indexer::is_tx_relevant`] implementation of `I`.
-    /// Irrelevant transactions in `txs` will be ignored.
-    pub fn apply_block_relevant(
-        &mut self,
-        block: &Block,
-        height: u32,
-    ) -> ChangeSet<A, I::ChangeSet> {
-        let block_id = BlockId {
-            hash: block.block_hash(),
-            height,
-        };
-        let mut changeset = ChangeSet::<A, I::ChangeSet>::default();
-        for (tx_pos, tx) in block.txdata.iter().enumerate() {
-            changeset.indexer.append(self.index.index_tx(tx));
-            if self.index.is_tx_relevant(tx) {
-                let txid = tx.txid();
-                let anchor = A::from_block_position(block, block_id, tx_pos);
-                changeset.graph.append(self.graph.insert_tx(tx.clone()));
-                changeset
-                    .graph
-                    .append(self.graph.insert_anchor(txid, anchor));
-            }
-        }
-        changeset
-    }
-
-    /// Batch insert all transactions of the given `block` of `height`.
-    ///
-    /// Each inserted transaction's anchor will be constructed from
-    /// [`AnchorFromBlockPosition::from_block_position`].
-    ///
-    /// To only insert relevant transactions, use [`apply_block_relevant`] instead.
-    ///
-    /// [`apply_block_relevant`]: IndexedTxGraph::apply_block_relevant
-    pub fn apply_block(&mut self, block: Block, height: u32) -> ChangeSet<A, I::ChangeSet> {
-        let block_id = BlockId {
-            hash: block.block_hash(),
-            height,
-        };
-        let mut graph = tx_graph::ChangeSet::default();
-        for (tx_pos, tx) in block.txdata.iter().enumerate() {
-            let anchor = A::from_block_position(&block, block_id, tx_pos);
-            graph.append(self.graph.insert_anchor(tx.txid(), anchor));
-            graph.append(self.graph.insert_tx(tx.clone()));
-        }
-        let indexer = self.index_tx_graph_changeset(&graph);
-        ChangeSet { graph, indexer }
-    }
-}
-
-/// Represents changes to an [`IndexedTxGraph`].
-#[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(
-    feature = "serde",
-    derive(serde::Deserialize, serde::Serialize),
-    serde(
-        crate = "serde_crate",
-        bound(
-            deserialize = "A: Ord + serde::Deserialize<'de>, IA: serde::Deserialize<'de>",
-            serialize = "A: Ord + serde::Serialize, IA: serde::Serialize"
-        )
-    )
-)]
-#[must_use]
-pub struct ChangeSet<A, IA> {
-    /// [`TxGraph`] changeset.
-    pub graph: tx_graph::ChangeSet<A>,
-    /// [`Indexer`] changeset.
-    pub indexer: IA,
-}
-
-impl<A, IA: Default> Default for ChangeSet<A, IA> {
-    fn default() -> Self {
-        Self {
-            graph: Default::default(),
-            indexer: Default::default(),
-        }
-    }
-}
-
-impl<A: Anchor, IA: Append> Append for ChangeSet<A, IA> {
-    fn append(&mut self, other: Self) {
-        self.graph.append(other.graph);
-        self.indexer.append(other.indexer);
-    }
-
-    fn is_empty(&self) -> bool {
-        self.graph.is_empty() && self.indexer.is_empty()
-    }
-}
-
-impl<A, IA: Default> From<tx_graph::ChangeSet<A>> for ChangeSet<A, IA> {
-    fn from(graph: tx_graph::ChangeSet<A>) -> Self {
-        Self {
-            graph,
-            ..Default::default()
-        }
-    }
-}
-
-impl<A, K> From<keychain::ChangeSet<K>> for ChangeSet<A, keychain::ChangeSet<K>> {
-    fn from(indexer: keychain::ChangeSet<K>) -> Self {
-        Self {
-            graph: Default::default(),
-            indexer,
-        }
-    }
-}
-
-/// Utilities for indexing transaction data.
-///
-/// Types which implement this trait can be used to construct an [`IndexedTxGraph`].
-/// This trait's methods should rarely be called directly.
-pub trait Indexer {
-    /// The resultant "changeset" when new transaction data is indexed.
-    type ChangeSet;
-
-    /// Scan and index the given `outpoint` and `txout`.
-    fn index_txout(&mut self, outpoint: OutPoint, txout: &TxOut) -> Self::ChangeSet;
-
-    /// Scans a transaction for relevant outpoints, which are stored and indexed internally.
-    fn index_tx(&mut self, tx: &Transaction) -> Self::ChangeSet;
-
-    /// Apply changeset to itself.
-    fn apply_changeset(&mut self, changeset: Self::ChangeSet);
-
-    /// Determines the [`ChangeSet`] between `self` and an empty [`Indexer`].
-    fn initial_changeset(&self) -> Self::ChangeSet;
-
-    /// Determines whether the transaction should be included in the index.
-    fn is_tx_relevant(&self, tx: &Transaction) -> bool;
-}
--- a/crates/chain/src/keychain.rs
+++ b/crates/chain/src/keychain.rs
@@ -8,23 +8,40 @@
 //! has a `txout` containing an indexed script pubkey). Internally, this uses [`SpkTxOutIndex`], but
 //! also maintains "revealed" and "lookahead" index counts per keychain.
 //!
+//! [`KeychainTracker`] combines [`ChainGraph`] and [`KeychainTxOutIndex`] and enforces atomic
+//! changes between both these structures. [`KeychainScan`] is a structure used to update to
+//! [`KeychainTracker`] and changes made on a [`KeychainTracker`] are reported by
+//! [`KeychainChangeSet`]s.
+//!
 //! [`SpkTxOutIndex`]: crate::SpkTxOutIndex
+use crate::{
+    chain_graph::{self, ChainGraph},
+    collections::BTreeMap,
+    sparse_chain::ChainPosition,
+    tx_graph::TxGraph,
+    ForEachTxOut,
+};

-use crate::{collections::BTreeMap, Append};
-
+#[cfg(feature = "miniscript")]
+pub mod persist;
+#[cfg(feature = "miniscript")]
+pub use persist::*;
+#[cfg(feature = "miniscript")]
+mod tracker;
+#[cfg(feature = "miniscript")]
+pub use tracker::*;
 #[cfg(feature = "miniscript")]
 mod txout_index;
 #[cfg(feature = "miniscript")]
 pub use txout_index::*;

 /// Represents updates to the derivation index of a [`KeychainTxOutIndex`].
-/// It maps each keychain `K` to its last revealed index.
 ///
-/// It can be applied to [`KeychainTxOutIndex`] with [`apply_changeset`]. [`ChangeSet`]s are
+/// It can be applied to [`KeychainTxOutIndex`] with [`apply_additions`]. [`DerivationAdditions] are
 /// monotone in that they will never decrease the revealed derivation index.
 ///
 /// [`KeychainTxOutIndex`]: crate::keychain::KeychainTxOutIndex
-/// [`apply_changeset`]: crate::keychain::KeychainTxOutIndex::apply_changeset
+/// [`apply_additions`]: crate::keychain::KeychainTxOutIndex::apply_additions
 #[derive(Clone, Debug, PartialEq)]
 #[cfg_attr(
    feature = "serde",
@@ -38,49 +55,158 @@ pub use txout_index::*;
    )
 )]
 #[must_use]
-pub struct ChangeSet<K>(pub BTreeMap<K, u32>);
+pub struct DerivationAdditions<K>(pub BTreeMap<K, u32>);
+
+impl<K> DerivationAdditions<K> {
+    /// Returns whether the additions are empty.
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }

-impl<K> ChangeSet<K> {
    /// Get the inner map of the keychain to its new derivation index.
    pub fn as_inner(&self) -> &BTreeMap<K, u32> {
        &self.0
    }
 }

-impl<K: Ord> Append for ChangeSet<K> {
-    /// Append another [`ChangeSet`] into self.
+impl<K: Ord> DerivationAdditions<K> {
+    /// Append another [`DerivationAdditions`] into self.
    ///
    /// If the keychain already exists, increase the index when the other's index > self's index.
    /// If the keychain did not exist, append the new keychain.
-    fn append(&mut self, mut other: Self) {
+    pub fn append(&mut self, mut other: Self) {
        self.0.iter_mut().for_each(|(key, index)| {
            if let Some(other_index) = other.0.remove(key) {
                *index = other_index.max(*index);
            }
        });
-        // We use `extend` instead of `BTreeMap::append` due to performance issues with `append`.
-        // Refer to https://github.com/rust-lang/rust/issues/34666#issuecomment-675658420
-        self.0.extend(other.0);
-    }

-    /// Returns whether the changeset are empty.
-    fn is_empty(&self) -> bool {
-        self.0.is_empty()
+        self.0.append(&mut other.0);
    }
 }

-impl<K> Default for ChangeSet<K> {
+impl<K> Default for DerivationAdditions<K> {
    fn default() -> Self {
        Self(Default::default())
    }
 }

-impl<K> AsRef<BTreeMap<K, u32>> for ChangeSet<K> {
+impl<K> AsRef<BTreeMap<K, u32>> for DerivationAdditions<K> {
    fn as_ref(&self) -> &BTreeMap<K, u32> {
        &self.0
    }
 }

+#[derive(Clone, Debug, PartialEq)]
+/// An update that includes the last active indexes of each keychain.
+pub struct KeychainScan<K, P> {
+    /// The update data in the form of a chain that could be applied
+    pub update: ChainGraph<P>,
+    /// The last active indexes of each keychain
+    pub last_active_indices: BTreeMap<K, u32>,
+}
+
+impl<K, P> Default for KeychainScan<K, P> {
+    fn default() -> Self {
+        Self {
+            update: Default::default(),
+            last_active_indices: Default::default(),
+        }
+    }
+}
+
+impl<K, P> From<ChainGraph<P>> for KeychainScan<K, P> {
+    fn from(update: ChainGraph<P>) -> Self {
+        KeychainScan {
+            update,
+            last_active_indices: Default::default(),
+        }
+    }
+}
+
+/// Represents changes to a [`KeychainTracker`].
+///
+/// This is essentially a combination of [`DerivationAdditions`] and [`chain_graph::ChangeSet`].
+#[derive(Clone, Debug)]
+#[cfg_attr(
+    feature = "serde",
+    derive(serde::Deserialize, serde::Serialize),
+    serde(
+        crate = "serde_crate",
+        bound(
+            deserialize = "K: Ord + serde::Deserialize<'de>, P: serde::Deserialize<'de>",
+            serialize = "K: Ord + serde::Serialize, P: serde::Serialize"
+        )
+    )
+)]
+#[must_use]
+pub struct KeychainChangeSet<K, P> {
+    /// The changes in local keychain derivation indices
+    pub derivation_indices: DerivationAdditions<K>,
+    /// The changes that have occurred in the blockchain
+    pub chain_graph: chain_graph::ChangeSet<P>,
+}
+
+impl<K, P> Default for KeychainChangeSet<K, P> {
+    fn default() -> Self {
+        Self {
+            chain_graph: Default::default(),
+            derivation_indices: Default::default(),
+        }
+    }
+}
+
+impl<K, P> KeychainChangeSet<K, P> {
+    /// Returns whether the [`KeychainChangeSet`] is empty (no changes recorded).
+    pub fn is_empty(&self) -> bool {
+        self.chain_graph.is_empty() && self.derivation_indices.is_empty()
+    }
+
+    /// Appends the changes in `other` into `self` such that applying `self` afterward has the same
+    /// effect as sequentially applying the original `self` and `other`.
+    ///
+    /// Note the derivation indices cannot be decreased, so `other` will only change the derivation
+    /// index for a keychain, if it's value is higher than the one in `self`.
+    pub fn append(&mut self, other: KeychainChangeSet<K, P>)
+    where
+        K: Ord,
+        P: ChainPosition,
+    {
+        self.derivation_indices.append(other.derivation_indices);
+        self.chain_graph.append(other.chain_graph);
+    }
+}
+
+impl<K, P> From<chain_graph::ChangeSet<P>> for KeychainChangeSet<K, P> {
+    fn from(changeset: chain_graph::ChangeSet<P>) -> Self {
+        Self {
+            chain_graph: changeset,
+            ..Default::default()
+        }
+    }
+}
+
+impl<K, P> From<DerivationAdditions<K>> for KeychainChangeSet<K, P> {
+    fn from(additions: DerivationAdditions<K>) -> Self {
+        Self {
+            derivation_indices: additions,
+            ..Default::default()
+        }
+    }
+}
+
+impl<K, P> AsRef<TxGraph> for KeychainScan<K, P> {
+    fn as_ref(&self) -> &TxGraph {
+        self.update.graph()
+    }
+}
+
+impl<K, P> ForEachTxOut for KeychainChangeSet<K, P> {
+    fn for_each_txout(&self, f: impl FnMut((bitcoin::OutPoint, &bitcoin::TxOut))) {
+        self.chain_graph.for_each_txout(f)
+    }
+}
+
 /// Balance, differentiated into various categories.
 #[derive(Debug, PartialEq, Eq, Clone, Default)]
 #[cfg_attr(
@@ -139,8 +265,9 @@ impl core::ops::Add for Balance {

 #[cfg(test)]
 mod test {
-    use super::*;
+    use crate::TxHeight;

+    use super::*;
    #[test]
    fn append_keychain_derivation_indices() {
        #[derive(Ord, PartialOrd, Eq, PartialEq, Clone, Debug)]
@@ -158,18 +285,25 @@ mod test {
        rhs_di.insert(Keychain::Two, 5);
        lhs_di.insert(Keychain::Three, 3);
        rhs_di.insert(Keychain::Four, 4);
+        let mut lhs = KeychainChangeSet {
+            derivation_indices: DerivationAdditions(lhs_di),
+            chain_graph: chain_graph::ChangeSet::<TxHeight>::default(),
+        };
+
+        let rhs = KeychainChangeSet {
+            derivation_indices: DerivationAdditions(rhs_di),
+            chain_graph: chain_graph::ChangeSet::<TxHeight>::default(),
+        };

-        let mut lhs = ChangeSet(lhs_di);
-        let rhs = ChangeSet(rhs_di);
        lhs.append(rhs);

        // Exiting index doesn't update if the new index in `other` is lower than `self`.
-        assert_eq!(lhs.0.get(&Keychain::One), Some(&7));
+        assert_eq!(lhs.derivation_indices.0.get(&Keychain::One), Some(&7));
        // Existing index updates if the new index in `other` is higher than `self`.
-        assert_eq!(lhs.0.get(&Keychain::Two), Some(&5));
+        assert_eq!(lhs.derivation_indices.0.get(&Keychain::Two), Some(&5));
        // Existing index is unchanged if keychain doesn't exist in `other`.
-        assert_eq!(lhs.0.get(&Keychain::Three), Some(&3));
+        assert_eq!(lhs.derivation_indices.0.get(&Keychain::Three), Some(&3));
        // New keychain gets added if the keychain is in `other` but not in `self`.
-        assert_eq!(lhs.0.get(&Keychain::Four), Some(&4));
+        assert_eq!(lhs.derivation_indices.0.get(&Keychain::Four), Some(&4));
    }
 }
--- a/crates/chain/src/keychain/persist.rs
+++ b/crates/chain/src/keychain/persist.rs
@@ -0,0 +1,108 @@
+//! Persistence for changes made to a [`KeychainTracker`].
+//!
+//! BDK's [`KeychainTracker`] needs somewhere to persist changes it makes during operation.
+//! Operations like giving out a new address are crucial to persist so that next time the
+//! application is loaded, it can find transactions related to that address.
+//!
+//! Note that the [`KeychainTracker`] does not read this persisted data during operation since it
+//! always has a copy in memory.
+//!
+//! [`KeychainTracker`]: crate::keychain::KeychainTracker
+
+use crate::{keychain, sparse_chain::ChainPosition};
+
+/// `Persist` wraps a [`PersistBackend`] to create a convenient staging area for changes before they
+/// are persisted. Not all changes made to the [`KeychainTracker`] need to be written to disk right
+/// away so you can use [`Persist::stage`] to *stage* it first and then [`Persist::commit`] to
+/// finally, write it to disk.
+///
+/// [`KeychainTracker`]: keychain::KeychainTracker
+#[derive(Debug)]
+pub struct Persist<K, P, B> {
+    backend: B,
+    stage: keychain::KeychainChangeSet<K, P>,
+}
+
+impl<K, P, B> Persist<K, P, B> {
+    /// Create a new `Persist` from a [`PersistBackend`].
+    pub fn new(backend: B) -> Self {
+        Self {
+            backend,
+            stage: Default::default(),
+        }
+    }
+
+    /// Stage a `changeset` to later persistence with [`commit`].
+    ///
+    /// [`commit`]: Self::commit
+    pub fn stage(&mut self, changeset: keychain::KeychainChangeSet<K, P>)
+    where
+        K: Ord,
+        P: ChainPosition,
+    {
+        self.stage.append(changeset)
+    }
+
+    /// Get the changes that haven't been committed yet
+    pub fn staged(&self) -> &keychain::KeychainChangeSet<K, P> {
+        &self.stage
+    }
+
+    /// Commit the staged changes to the underlying persistence backend.
+    ///
+    /// Returns a backend-defined error if this fails.
+    pub fn commit(&mut self) -> Result<(), B::WriteError>
+    where
+        B: PersistBackend<K, P>,
+    {
+        self.backend.append_changeset(&self.stage)?;
+        self.stage = Default::default();
+        Ok(())
+    }
+}
+
+/// A persistence backend for [`Persist`].
+pub trait PersistBackend<K, P> {
+    /// The error the backend returns when it fails to write.
+    type WriteError: core::fmt::Debug;
+
+    /// The error the backend returns when it fails to load.
+    type LoadError: core::fmt::Debug;
+
+    /// Appends a new changeset to the persistent backend.
+    ///
+    /// It is up to the backend what it does with this. It could store every changeset in a list or
+    /// it inserts the actual changes into a more structured database. All it needs to guarantee is
+    /// that [`load_into_keychain_tracker`] restores a keychain tracker to what it should be if all
+    /// changesets had been applied sequentially.
+    ///
+    /// [`load_into_keychain_tracker`]: Self::load_into_keychain_tracker
+    fn append_changeset(
+        &mut self,
+        changeset: &keychain::KeychainChangeSet<K, P>,
+    ) -> Result<(), Self::WriteError>;
+
+    /// Applies all the changesets the backend has received to `tracker`.
+    fn load_into_keychain_tracker(
+        &mut self,
+        tracker: &mut keychain::KeychainTracker<K, P>,
+    ) -> Result<(), Self::LoadError>;
+}
+
+impl<K, P> PersistBackend<K, P> for () {
+    type WriteError = ();
+    type LoadError = ();
+
+    fn append_changeset(
+        &mut self,
+        _changeset: &keychain::KeychainChangeSet<K, P>,
+    ) -> Result<(), Self::WriteError> {
+        Ok(())
+    }
+    fn load_into_keychain_tracker(
+        &mut self,
+        _tracker: &mut keychain::KeychainTracker<K, P>,
+    ) -> Result<(), Self::LoadError> {
+        Ok(())
+    }
+}
--- a/crates/chain/src/keychain/tracker.rs
+++ b/crates/chain/src/keychain/tracker.rs
@@ -0,0 +1,308 @@
+use bitcoin::Transaction;
+use miniscript::{Descriptor, DescriptorPublicKey};
+
+use crate::{
+    chain_graph::{self, ChainGraph},
+    collections::*,
+    keychain::{KeychainChangeSet, KeychainScan, KeychainTxOutIndex},
+    sparse_chain::{self, SparseChain},
+    tx_graph::TxGraph,
+    BlockId, FullTxOut, TxHeight,
+};
+
+use super::{Balance, DerivationAdditions};
+
+/// A convenient combination of a [`KeychainTxOutIndex`] and a [`ChainGraph`].
+///
+/// The [`KeychainTracker`] atomically updates its [`KeychainTxOutIndex`] whenever new chain data is
+/// incorporated into its internal [`ChainGraph`].
+#[derive(Clone, Debug)]
+pub struct KeychainTracker<K, P> {
+    /// Index between script pubkeys to transaction outputs
+    pub txout_index: KeychainTxOutIndex<K>,
+    chain_graph: ChainGraph<P>,
+}
+
+impl<K, P> KeychainTracker<K, P>
+where
+    P: sparse_chain::ChainPosition,
+    K: Ord + Clone + core::fmt::Debug,
+{
+    /// Add a keychain to the tracker's `txout_index` with a descriptor to derive addresses.
+    /// This is just shorthand for calling [`KeychainTxOutIndex::add_keychain`] on the internal
+    /// `txout_index`.
+    ///
+    /// Adding a keychain means you will be able to derive new script pubkeys under that keychain
+    /// and the tracker will discover transaction outputs with those script pubkeys.
+    pub fn add_keychain(&mut self, keychain: K, descriptor: Descriptor<DescriptorPublicKey>) {
+        self.txout_index.add_keychain(keychain, descriptor)
+    }
+
+    /// Get the internal map of keychains to their descriptors. This is just shorthand for calling
+    /// [`KeychainTxOutIndex::keychains`] on the internal `txout_index`.
+    pub fn keychains(&mut self) -> &BTreeMap<K, Descriptor<DescriptorPublicKey>> {
+        self.txout_index.keychains()
+    }
+
+    /// Get the checkpoint limit of the internal [`SparseChain`].
+    ///
+    /// Refer to [`SparseChain::checkpoint_limit`] for more.
+    pub fn checkpoint_limit(&self) -> Option<usize> {
+        self.chain_graph.checkpoint_limit()
+    }
+
+    /// Set the checkpoint limit of the internal [`SparseChain`].
+    ///
+    /// Refer to [`SparseChain::set_checkpoint_limit`] for more.
+    pub fn set_checkpoint_limit(&mut self, limit: Option<usize>) {
+        self.chain_graph.set_checkpoint_limit(limit)
+    }
+
+    /// Determines the resultant [`KeychainChangeSet`] if the given [`KeychainScan`] is applied.
+    ///
+    /// Internally, we call [`ChainGraph::determine_changeset`] and also determine the additions of
+    /// [`KeychainTxOutIndex`].
+    pub fn determine_changeset(
+        &self,
+        scan: &KeychainScan<K, P>,
+    ) -> Result<KeychainChangeSet<K, P>, chain_graph::UpdateError<P>> {
+        // TODO: `KeychainTxOutIndex::determine_additions`
+        let mut derivation_indices = scan.last_active_indices.clone();
+        derivation_indices.retain(|keychain, index| {
+            match self.txout_index.last_revealed_index(keychain) {
+                Some(existing) => *index > existing,
+                None => true,
+            }
+        });
+
+        Ok(KeychainChangeSet {
+            derivation_indices: DerivationAdditions(derivation_indices),
+            chain_graph: self.chain_graph.determine_changeset(&scan.update)?,
+        })
+    }
+
+    /// Directly applies a [`KeychainScan`] on [`KeychainTracker`].
+    ///
+    /// This is equivalent to calling [`determine_changeset`] and [`apply_changeset`] in sequence.
+    ///
+    /// [`determine_changeset`]: Self::determine_changeset
+    /// [`apply_changeset`]: Self::apply_changeset
+    pub fn apply_update(
+        &mut self,
+        scan: KeychainScan<K, P>,
+    ) -> Result<KeychainChangeSet<K, P>, chain_graph::UpdateError<P>> {
+        let changeset = self.determine_changeset(&scan)?;
+        self.apply_changeset(changeset.clone());
+        Ok(changeset)
+    }
+
+    /// Applies the changes in `changeset` to [`KeychainTracker`].
+    ///
+    /// Internally, this calls [`KeychainTxOutIndex::apply_additions`] and
+    /// [`ChainGraph::apply_changeset`] in sequence.
+    pub fn apply_changeset(&mut self, changeset: KeychainChangeSet<K, P>) {
+        let KeychainChangeSet {
+            derivation_indices,
+            chain_graph,
+        } = changeset;
+        self.txout_index.apply_additions(derivation_indices);
+        let _ = self.txout_index.scan(&chain_graph);
+        self.chain_graph.apply_changeset(chain_graph)
+    }
+
+    /// Iterates through [`FullTxOut`]s that are considered to exist in our representation of the
+    /// blockchain/mempool.
+    ///
+    /// In other words, these are `txout`s of confirmed and in-mempool transactions, based on our
+    /// view of the blockchain/mempool.
+    pub fn full_txouts(&self) -> impl Iterator<Item = (&(K, u32), FullTxOut<P>)> + '_ {
+        self.txout_index
+            .txouts()
+            .filter_map(move |(spk_i, op, _)| Some((spk_i, self.chain_graph.full_txout(op)?)))
+    }
+
+    /// Iterates through [`FullTxOut`]s that are unspent outputs.
+    ///
+    /// Refer to [`full_txouts`] for more.
+    ///
+    /// [`full_txouts`]: Self::full_txouts
+    pub fn full_utxos(&self) -> impl Iterator<Item = (&(K, u32), FullTxOut<P>)> + '_ {
+        self.full_txouts()
+            .filter(|(_, txout)| txout.spent_by.is_none())
+    }
+
+    /// Returns a reference to the internal [`ChainGraph`].
+    pub fn chain_graph(&self) -> &ChainGraph<P> {
+        &self.chain_graph
+    }
+
+    /// Returns a reference to the internal [`TxGraph`] (which is part of the [`ChainGraph`]).
+    pub fn graph(&self) -> &TxGraph {
+        self.chain_graph().graph()
+    }
+
+    /// Returns a reference to the internal [`SparseChain`] (which is part of the [`ChainGraph`]).
+    pub fn chain(&self) -> &SparseChain<P> {
+        self.chain_graph().chain()
+    }
+
+    /// Determines the changes as a result of inserting `block_id` (a height and block hash) into the
+    /// tracker.
+    ///
+    /// The caller is responsible for guaranteeing that a block exists at that height. If a
+    /// checkpoint already exists at that height with a different hash; this will return an error.
+    /// Otherwise it will return `Ok(true)` if the checkpoint didn't already exist or `Ok(false)`
+    /// if it did.
+    ///
+    /// **Warning**: This function modifies the internal state of the tracker. You are responsible
+    /// for persisting these changes to disk if you need to restore them.
+    pub fn insert_checkpoint_preview(
+        &self,
+        block_id: BlockId,
+    ) -> Result<KeychainChangeSet<K, P>, chain_graph::InsertCheckpointError> {
+        Ok(KeychainChangeSet {
+            chain_graph: self.chain_graph.insert_checkpoint_preview(block_id)?,
+            ..Default::default()
+        })
+    }
+
+    /// Directly insert a `block_id` into the tracker.
+    ///
+    /// This is equivalent of calling [`insert_checkpoint_preview`] and [`apply_changeset`] in
+    /// sequence.
+    ///
+    /// [`insert_checkpoint_preview`]: Self::insert_checkpoint_preview
+    /// [`apply_changeset`]: Self::apply_changeset
+    pub fn insert_checkpoint(
+        &mut self,
+        block_id: BlockId,
+    ) -> Result<KeychainChangeSet<K, P>, chain_graph::InsertCheckpointError> {
+        let changeset = self.insert_checkpoint_preview(block_id)?;
+        self.apply_changeset(changeset.clone());
+        Ok(changeset)
+    }
+
+    /// Determines the changes as a result of inserting a transaction into the inner [`ChainGraph`]
+    /// and optionally into the inner chain at `position`.
+    ///
+    /// **Warning**: This function modifies the internal state of the chain graph. You are
+    /// responsible for persisting these changes to disk if you need to restore them.
+    pub fn insert_tx_preview(
+        &self,
+        tx: Transaction,
+        pos: P,
+    ) -> Result<KeychainChangeSet<K, P>, chain_graph::InsertTxError<P>> {
+        Ok(KeychainChangeSet {
+            chain_graph: self.chain_graph.insert_tx_preview(tx, pos)?,
+            ..Default::default()
+        })
+    }
+
+    /// Directly insert a transaction into the inner [`ChainGraph`] and optionally into the inner
+    /// chain at `position`.
+    ///
+    /// This is equivalent of calling [`insert_tx_preview`] and [`apply_changeset`] in sequence.
+    ///
+    /// [`insert_tx_preview`]: Self::insert_tx_preview
+    /// [`apply_changeset`]: Self::apply_changeset
+    pub fn insert_tx(
+        &mut self,
+        tx: Transaction,
+        pos: P,
+    ) -> Result<KeychainChangeSet<K, P>, chain_graph::InsertTxError<P>> {
+        let changeset = self.insert_tx_preview(tx, pos)?;
+        self.apply_changeset(changeset.clone());
+        Ok(changeset)
+    }
+
+    /// Returns the *balance* of the keychain, i.e., the value of unspent transaction outputs tracked.
+    ///
+    /// The caller provides a `should_trust` predicate which must decide whether the value of
+    /// unconfirmed outputs on this keychain are guaranteed to be realized or not. For example:
+    ///
+    /// - For an *internal* (change) keychain, `should_trust` should generally be `true` since even if
+    /// you lose an internal output due to eviction, you will always gain back the value from whatever output the
+    /// unconfirmed transaction was spending (since that output is presumably from your wallet).
+    /// - For an *external* keychain, you might want `should_trust` to return  `false` since someone may cancel (by double spending)
+    /// a payment made to addresses on that keychain.
+    ///
+    /// When in doubt set `should_trust` to return false. This doesn't do anything other than change
+    /// where the unconfirmed output's value is accounted for in `Balance`.
+    pub fn balance(&self, mut should_trust: impl FnMut(&K) -> bool) -> Balance {
+        let mut immature = 0;
+        let mut trusted_pending = 0;
+        let mut untrusted_pending = 0;
+        let mut confirmed = 0;
+        let last_sync_height = self.chain().latest_checkpoint().map(|latest| latest.height);
+        for ((keychain, _), utxo) in self.full_utxos() {
+            let chain_position = &utxo.chain_position;
+
+            match chain_position.height() {
+                TxHeight::Confirmed(_) => {
+                    if utxo.is_on_coinbase {
+                        if utxo.is_mature(
+                            last_sync_height
+                                .expect("since it's confirmed we must have a checkpoint"),
+                        ) {
+                            confirmed += utxo.txout.value;
+                        } else {
+                            immature += utxo.txout.value;
+                        }
+                    } else {
+                        confirmed += utxo.txout.value;
+                    }
+                }
+                TxHeight::Unconfirmed => {
+                    if should_trust(keychain) {
+                        trusted_pending += utxo.txout.value;
+                    } else {
+                        untrusted_pending += utxo.txout.value;
+                    }
+                }
+            }
+        }
+
+        Balance {
+            immature,
+            trusted_pending,
+            untrusted_pending,
+            confirmed,
+        }
+    }
+
+    /// Returns the balance of all spendable confirmed unspent outputs of this tracker at a
+    /// particular height.
+    pub fn balance_at(&self, height: u32) -> u64 {
+        self.full_txouts()
+            .filter(|(_, full_txout)| full_txout.is_spendable_at(height))
+            .map(|(_, full_txout)| full_txout.txout.value)
+            .sum()
+    }
+}
+
+impl<K, P> Default for KeychainTracker<K, P> {
+    fn default() -> Self {
+        Self {
+            txout_index: Default::default(),
+            chain_graph: Default::default(),
+        }
+    }
+}
+
+impl<K, P> AsRef<SparseChain<P>> for KeychainTracker<K, P> {
+    fn as_ref(&self) -> &SparseChain<P> {
+        self.chain_graph.chain()
+    }
+}
+
+impl<K, P> AsRef<TxGraph> for KeychainTracker<K, P> {
+    fn as_ref(&self) -> &TxGraph {
+        self.chain_graph.graph()
+    }
+}
+
+impl<K, P> AsRef<ChainGraph<P>> for KeychainTracker<K, P> {
+    fn as_ref(&self) -> &ChainGraph<P> {
+        &self.chain_graph
+    }
+}
--- a/crates/chain/src/keychain/txout_index.rs
+++ b/crates/chain/src/keychain/txout_index.rs
@@ -1,60 +1,28 @@
 use crate::{
    collections::*,
-    indexed_tx_graph::Indexer,
    miniscript::{Descriptor, DescriptorPublicKey},
-    spk_iter::BIP32_MAX_INDEX,
-    SpkIterator, SpkTxOutIndex,
-};
-use bitcoin::{OutPoint, Script, Transaction, TxOut, Txid};
-use core::{
-    fmt::Debug,
-    ops::{Bound, RangeBounds},
+    ForEachTxOut, SpkTxOutIndex,
 };
+use alloc::{borrow::Cow, vec::Vec};
+use bitcoin::{secp256k1::Secp256k1, OutPoint, Script, TxOut};
+use core::{fmt::Debug, ops::Deref};

-use crate::Append;
+use super::DerivationAdditions;

-const DEFAULT_LOOKAHEAD: u32 = 25;
+/// Maximum [BIP32](https://bips.xyz/32) derivation index.
+pub const BIP32_MAX_INDEX: u32 = (1 << 31) - 1;

-/// [`KeychainTxOutIndex`] controls how script pubkeys are revealed for multiple keychains, and
-/// indexes [`TxOut`]s with them.
+/// A convenient wrapper around [`SpkTxOutIndex`] that relates script pubkeys to miniscript public
+/// [`Descriptor`]s.
 ///
-/// A single keychain is a chain of script pubkeys derived from a single [`Descriptor`]. Keychains
-/// are identified using the `K` generic. Script pubkeys are identified by the keychain that they
-/// are derived from `K`, as well as the derivation index `u32`.
+/// Descriptors are referenced by the provided keychain generic (`K`).
 ///
-/// # Revealed script pubkeys
+/// Script pubkeys for a descriptor are revealed chronologically from index 0. I.e., If the last
+/// revealed index of a descriptor is 5; scripts of indices 0 to 4 are guaranteed to be already
+/// revealed. In addition to revealed scripts, we have a `lookahead` parameter for each keychain,
+/// which defines the number of script pubkeys to store ahead of the last revealed index.
 ///
-/// Tracking how script pubkeys are revealed is useful for collecting chain data. For example, if
-/// the user has requested 5 script pubkeys (to receive money with), we only need to use those
-/// script pubkeys to scan for chain data.
-///
-/// Call [`reveal_to_target`] or [`reveal_next_spk`] to reveal more script pubkeys.
-/// Call [`revealed_keychain_spks`] or [`revealed_spks`] to iterate through revealed script pubkeys.
-///
-/// # Lookahead script pubkeys
-///
-/// When an user first recovers a wallet (i.e. from a recovery phrase and/or descriptor), we will
-/// NOT have knowledge of which script pubkeys are revealed. So when we index a transaction or
-/// txout (using [`index_tx`]/[`index_txout`]) we scan the txouts against script pubkeys derived
-/// above the last revealed index. These additionally-derived script pubkeys are called the
-/// lookahead.
-///
-/// The [`KeychainTxOutIndex`] is constructed with the `lookahead` and cannot be altered. The
-/// default `lookahead` count is 1000. Use [`new`] to set a custom `lookahead`.
-///
-/// # Unbounded script pubkey iterator
-///
-/// For script-pubkey-based chain sources (such as Electrum/Esplora), an initial scan is best done
-/// by iterating though derived script pubkeys one by one and requesting transaction histories for
-/// each script pubkey. We will stop after x-number of script pubkeys have empty histories. An
-/// unbounded script pubkey iterator is useful to pass to such a chain source.
-///
-/// Call [`unbounded_spk_iter`] to get an unbounded script pubkey iterator for a given keychain.
-/// Call [`all_unbounded_spk_iters`] to get unbounded script pubkey iterators for all keychains.
-///
-/// # Change sets
-///
-/// Methods that can update the last revealed index will return [`super::ChangeSet`] to report
+/// Methods that could update the last revealed index will return [`DerivationAdditions`] to report
 /// these changes. This can be persisted for future recovery.
 ///
 /// ## Synopsis
@@ -79,7 +47,7 @@ const DEFAULT_LOOKAHEAD: u32 = 25;
 /// # let secp = bdk_chain::bitcoin::secp256k1::Secp256k1::signing_only();
 /// # let (external_descriptor,_) = Descriptor::<DescriptorPublicKey>::parse_descriptor(&secp, "tr([73c5da0a/86'/0'/0']xprv9xgqHN7yz9MwCkxsBPN5qetuNdQSUttZNKw1dcYTV4mkaAFiBVGQziHs3NRSWMkCzvgjEe3n9xV8oYywvM8at9yRqyaZVz6TYYhX98VjsUk/0/*)").unwrap();
 /// # let (internal_descriptor,_) = Descriptor::<DescriptorPublicKey>::parse_descriptor(&secp, "tr([73c5da0a/86'/0'/0']xprv9xgqHN7yz9MwCkxsBPN5qetuNdQSUttZNKw1dcYTV4mkaAFiBVGQziHs3NRSWMkCzvgjEe3n9xV8oYywvM8at9yRqyaZVz6TYYhX98VjsUk/1/*)").unwrap();
-/// # let (descriptor_for_user_42, _) = Descriptor::<DescriptorPublicKey>::parse_descriptor(&secp, "tr([73c5da0a/86'/0'/0']xprv9xgqHN7yz9MwCkxsBPN5qetuNdQSUttZNKw1dcYTV4mkaAFiBVGQziHs3NRSWMkCzvgjEe3n9xV8oYywvM8at9yRqyaZVz6TYYhX98VjsUk/2/*)").unwrap();
+/// # let descriptor_for_user_42 = external_descriptor.clone();
 /// txout_index.add_keychain(MyKeychain::External, external_descriptor);
 /// txout_index.add_keychain(MyKeychain::Internal, internal_descriptor);
 /// txout_index.add_keychain(MyKeychain::MyAppUser { user_id: 42 }, descriptor_for_user_42);
@@ -90,15 +58,6 @@ const DEFAULT_LOOKAHEAD: u32 = 25;
 /// [`Ord`]: core::cmp::Ord
 /// [`SpkTxOutIndex`]: crate::spk_txout_index::SpkTxOutIndex
 /// [`Descriptor`]: crate::miniscript::Descriptor
-/// [`reveal_to_target`]: KeychainTxOutIndex::reveal_to_target
-/// [`reveal_next_spk`]: KeychainTxOutIndex::reveal_next_spk
-/// [`revealed_keychain_spks`]: KeychainTxOutIndex::revealed_keychain_spks
-/// [`revealed_spks`]: KeychainTxOutIndex::revealed_spks
-/// [`index_tx`]: KeychainTxOutIndex::index_tx
-/// [`index_txout`]: KeychainTxOutIndex::index_txout
-/// [`new`]: KeychainTxOutIndex::new
-/// [`unbounded_spk_iter`]: KeychainTxOutIndex::unbounded_spk_iter
-/// [`all_unbounded_spk_iters`]: KeychainTxOutIndex::all_unbounded_spk_iters
 #[derive(Clone, Debug)]
 pub struct KeychainTxOutIndex<K> {
    inner: SpkTxOutIndex<(K, u32)>,
@@ -107,192 +66,67 @@ pub struct KeychainTxOutIndex<K> {
    // last revealed indexes
    last_revealed: BTreeMap<K, u32>,
    // lookahead settings for each keychain
-    lookahead: u32,
+    lookahead: BTreeMap<K, u32>,
 }

 impl<K> Default for KeychainTxOutIndex<K> {
    fn default() -> Self {
-        Self::new(DEFAULT_LOOKAHEAD)
-    }
-}
-
-impl<K: Clone + Ord + Debug> Indexer for KeychainTxOutIndex<K> {
-    type ChangeSet = super::ChangeSet<K>;
-
-    fn index_txout(&mut self, outpoint: OutPoint, txout: &TxOut) -> Self::ChangeSet {
-        match self.inner.scan_txout(outpoint, txout).cloned() {
-            Some((keychain, index)) => self.reveal_to_target(&keychain, index).1,
-            None => super::ChangeSet::default(),
-        }
-    }
-
-    fn index_tx(&mut self, tx: &bitcoin::Transaction) -> Self::ChangeSet {
-        let mut changeset = super::ChangeSet::<K>::default();
-        for (op, txout) in tx.output.iter().enumerate() {
-            changeset.append(self.index_txout(OutPoint::new(tx.txid(), op as u32), txout));
-        }
-        changeset
-    }
-
-    fn initial_changeset(&self) -> Self::ChangeSet {
-        super::ChangeSet(self.last_revealed.clone())
-    }
-
-    fn apply_changeset(&mut self, changeset: Self::ChangeSet) {
-        self.apply_changeset(changeset)
-    }
-
-    fn is_tx_relevant(&self, tx: &bitcoin::Transaction) -> bool {
-        self.inner.is_relevant(tx)
-    }
-}
-
-impl<K> KeychainTxOutIndex<K> {
-    /// Construct a [`KeychainTxOutIndex`] with the given `lookahead`.
-    ///
-    /// The `lookahead` is the number of script pubkeys to derive and cache from the internal
-    /// descriptors over and above the last revealed script index. Without a lookahead the index
-    /// will miss outputs you own when processing transactions whose output script pubkeys lie
-    /// beyond the last revealed index. In certain situations, such as when performing an initial
-    /// scan of the blockchain during wallet import, it may be uncertain or unknown what the index
-    /// of the last revealed script pubkey actually is.
-    ///
-    /// Refer to [struct-level docs](KeychainTxOutIndex) for more about `lookahead`.
-    pub fn new(lookahead: u32) -> Self {
        Self {
            inner: SpkTxOutIndex::default(),
-            keychains: BTreeMap::new(),
-            last_revealed: BTreeMap::new(),
-            lookahead,
+            keychains: BTreeMap::default(),
+            last_revealed: BTreeMap::default(),
+            lookahead: BTreeMap::default(),
        }
    }
 }

-/// Methods that are *re-exposed* from the internal [`SpkTxOutIndex`].
+impl<K> Deref for KeychainTxOutIndex<K> {
+    type Target = SpkTxOutIndex<(K, u32)>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.inner
+    }
+}
+
 impl<K: Clone + Ord + Debug> KeychainTxOutIndex<K> {
-    /// Return a reference to the internal [`SpkTxOutIndex`].
+    /// Scans an object for relevant outpoints, which are stored and indexed internally.
    ///
-    /// **WARNING:** The internal index will contain lookahead spks. Refer to
-    /// [struct-level docs](KeychainTxOutIndex) for more about `lookahead`.
+    /// If the matched script pubkey is part of the lookahead, the last stored index is updated for
+    /// the script pubkey's keychain and the [`DerivationAdditions`] returned will reflect the
+    /// change.
+    ///
+    /// Typically, this method is used in two situations:
+    ///
+    /// 1. After loading transaction data from the disk, you may scan over all the txouts to restore all
+    /// your txouts.
+    /// 2. When getting new data from the chain, you usually scan it before incorporating it into
+    /// your chain state (i.e., `SparseChain`, `ChainGraph`).
+    ///
+    /// See [`ForEachTxout`] for the types that support this.
+    ///
+    /// [`ForEachTxout`]: crate::ForEachTxOut
+    pub fn scan(&mut self, txouts: &impl ForEachTxOut) -> DerivationAdditions<K> {
+        let mut additions = DerivationAdditions::<K>::default();
+        txouts.for_each_txout(|(op, txout)| additions.append(self.scan_txout(op, txout)));
+        additions
+    }
+
+    /// Scan a single outpoint for a matching script pubkey.
+    ///
+    /// If it matches, this will store and index it.
+    pub fn scan_txout(&mut self, op: OutPoint, txout: &TxOut) -> DerivationAdditions<K> {
+        match self.inner.scan_txout(op, txout).cloned() {
+            Some((keychain, index)) => self.reveal_to_target(&keychain, index).1,
+            None => DerivationAdditions::default(),
+        }
+    }
+
+    /// Return a reference to the internal [`SpkTxOutIndex`].
    pub fn inner(&self) -> &SpkTxOutIndex<(K, u32)> {
        &self.inner
    }

-    /// Get a reference to the set of indexed outpoints.
-    pub fn outpoints(&self) -> &BTreeSet<((K, u32), OutPoint)> {
-        self.inner.outpoints()
-    }
-
-    /// Iterate over known txouts that spend to tracked script pubkeys.
-    pub fn txouts(
-        &self,
-    ) -> impl DoubleEndedIterator<Item = (K, u32, OutPoint, &TxOut)> + ExactSizeIterator {
-        self.inner
-            .txouts()
-            .map(|((k, i), op, txo)| (k.clone(), *i, op, txo))
-    }
-
-    /// Finds all txouts on a transaction that has previously been scanned and indexed.
-    pub fn txouts_in_tx(
-        &self,
-        txid: Txid,
-    ) -> impl DoubleEndedIterator<Item = (K, u32, OutPoint, &TxOut)> {
-        self.inner
-            .txouts_in_tx(txid)
-            .map(|((k, i), op, txo)| (k.clone(), *i, op, txo))
-    }
-
-    /// Return the [`TxOut`] of `outpoint` if it has been indexed.
-    ///
-    /// The associated keychain and keychain index of the txout's spk is also returned.
-    ///
-    /// This calls [`SpkTxOutIndex::txout`] internally.
-    pub fn txout(&self, outpoint: OutPoint) -> Option<(K, u32, &TxOut)> {
-        self.inner
-            .txout(outpoint)
-            .map(|((k, i), txo)| (k.clone(), *i, txo))
-    }
-
-    /// Return the script that exists under the given `keychain`'s `index`.
-    ///
-    /// This calls [`SpkTxOutIndex::spk_at_index`] internally.
-    pub fn spk_at_index(&self, keychain: K, index: u32) -> Option<&Script> {
-        self.inner.spk_at_index(&(keychain, index))
-    }
-
-    /// Returns the keychain and keychain index associated with the spk.
-    ///
-    /// This calls [`SpkTxOutIndex::index_of_spk`] internally.
-    pub fn index_of_spk(&self, script: &Script) -> Option<(K, u32)> {
-        self.inner.index_of_spk(script).cloned()
-    }
-
-    /// Returns whether the spk under the `keychain`'s `index` has been used.
-    ///
-    /// Here, "unused" means that after the script pubkey was stored in the index, the index has
-    /// never scanned a transaction output with it.
-    ///
-    /// This calls [`SpkTxOutIndex::is_used`] internally.
-    pub fn is_used(&self, keychain: K, index: u32) -> bool {
-        self.inner.is_used(&(keychain, index))
-    }
-
-    /// Marks the script pubkey at `index` as used even though the tracker hasn't seen an output
-    /// with it.
-    ///
-    /// This only has an effect when the `index` had been added to `self` already and was unused.
-    ///
-    /// Returns whether the `index` was initially present as `unused`.
-    ///
-    /// This is useful when you want to reserve a script pubkey for something but don't want to add
-    /// the transaction output using it to the index yet. Other callers will consider `index` on
-    /// `keychain` used until you call [`unmark_used`].
-    ///
-    /// This calls [`SpkTxOutIndex::mark_used`] internally.
-    ///
-    /// [`unmark_used`]: Self::unmark_used
-    pub fn mark_used(&mut self, keychain: K, index: u32) -> bool {
-        self.inner.mark_used(&(keychain, index))
-    }
-
-    /// Undoes the effect of [`mark_used`]. Returns whether the `index` is inserted back into
-    /// `unused`.
-    ///
-    /// Note that if `self` has scanned an output with this script pubkey, then this will have no
-    /// effect.
-    ///
-    /// This calls [`SpkTxOutIndex::unmark_used`] internally.
-    ///
-    /// [`mark_used`]: Self::mark_used
-    pub fn unmark_used(&mut self, keychain: K, index: u32) -> bool {
-        self.inner.unmark_used(&(keychain, index))
-    }
-
-    /// Computes total input value going from script pubkeys in the index (sent) and the total output
-    /// value going to script pubkeys in the index (received) in `tx`. For the `sent` to be computed
-    /// correctly, the output being spent must have already been scanned by the index. Calculating
-    /// received just uses the [`Transaction`] outputs directly, so it will be correct even if it has
-    /// not been scanned.
-    ///
-    /// This calls [`SpkTxOutIndex::sent_and_received`] internally.
-    pub fn sent_and_received(&self, tx: &Transaction) -> (u64, u64) {
-        self.inner.sent_and_received(tx)
-    }
-
-    /// Computes the net value that this transaction gives to the script pubkeys in the index and
-    /// *takes* from the transaction outputs in the index. Shorthand for calling
-    /// [`sent_and_received`] and subtracting sent from received.
-    ///
-    /// This calls [`SpkTxOutIndex::net_value`] internally.
-    ///
-    /// [`sent_and_received`]: Self::sent_and_received
-    pub fn net_value(&self, tx: &Transaction) -> i64 {
-        self.inner.net_value(tx)
-    }
-}
-
-impl<K: Clone + Ord + Debug> KeychainTxOutIndex<K> {
-    /// Return a reference to the internal map of keychain to descriptors.
+    /// Return a reference to the internal map of the keychain to descriptors.
    pub fn keychains(&self) -> &BTreeMap<K, Descriptor<DescriptorPublicKey>> {
        &self.keychains
    }
@@ -306,49 +140,84 @@ impl<K: Clone + Ord + Debug> KeychainTxOutIndex<K> {
    ///
    /// This will panic if a different `descriptor` is introduced to the same `keychain`.
    pub fn add_keychain(&mut self, keychain: K, descriptor: Descriptor<DescriptorPublicKey>) {
-        let old_descriptor = &*self
-            .keychains
-            .entry(keychain.clone())
-            .or_insert_with(|| descriptor.clone());
+        let old_descriptor = &*self.keychains.entry(keychain).or_insert(descriptor.clone());
        assert_eq!(
            &descriptor, old_descriptor,
            "keychain already contains a different descriptor"
        );
-        self.replenish_lookahead(&keychain, self.lookahead);
    }

-    /// Get the lookahead setting.
+    /// Return the lookahead setting for each keychain.
    ///
-    /// Refer to [`new`] for more information on the `lookahead`.
+    /// Refer to [`set_lookahead`] for a deeper explanation of the `lookahead`.
    ///
-    /// [`new`]: Self::new
-    pub fn lookahead(&self) -> u32 {
-        self.lookahead
+    /// [`set_lookahead`]: Self::set_lookahead
+    pub fn lookaheads(&self) -> &BTreeMap<K, u32> {
+        &self.lookahead
    }

-    /// Store lookahead scripts until `target_index` (inclusive).
+    /// Convenience method to call [`set_lookahead`] for all keychains.
    ///
-    /// This does not change the global `lookahead` setting.
-    pub fn lookahead_to_target(&mut self, keychain: &K, target_index: u32) {
-        let (next_index, _) = self.next_index(keychain);
-
-        let temp_lookahead = (target_index + 1)
-            .checked_sub(next_index)
-            .filter(|&index| index > 0);
-
-        if let Some(temp_lookahead) = temp_lookahead {
-            self.replenish_lookahead(keychain, temp_lookahead);
+    /// [`set_lookahead`]: Self::set_lookahead
+    pub fn set_lookahead_for_all(&mut self, lookahead: u32) {
+        for keychain in &self.keychains.keys().cloned().collect::<Vec<_>>() {
+            self.lookahead.insert(keychain.clone(), lookahead);
+            self.replenish_lookahead(keychain);
        }
    }

-    fn replenish_lookahead(&mut self, keychain: &K, lookahead: u32) {
+    /// Set the lookahead count for `keychain`.
+    ///
+    /// The lookahead is the number of scripts to cache ahead of the last stored script index. This
+    /// is useful during a scan via [`scan`] or [`scan_txout`].
+    ///
+    /// # Panics
+    ///
+    /// This will panic if the `keychain` does not exist.
+    ///
+    /// [`scan`]: Self::scan
+    /// [`scan_txout`]: Self::scan_txout
+    pub fn set_lookahead(&mut self, keychain: &K, lookahead: u32) {
+        self.lookahead.insert(keychain.clone(), lookahead);
+        self.replenish_lookahead(keychain);
+    }
+
+    /// Convenience method to call [`lookahead_to_target`] for multiple keychains.
+    ///
+    /// [`lookahead_to_target`]: Self::lookahead_to_target
+    pub fn lookahead_to_target_multi(&mut self, target_indexes: BTreeMap<K, u32>) {
+        for (keychain, target_index) in target_indexes {
+            self.lookahead_to_target(&keychain, target_index)
+        }
+    }
+
+    /// Store lookahead scripts until `target_index`.
+    ///
+    /// This does not change the `lookahead` setting.
+    pub fn lookahead_to_target(&mut self, keychain: &K, target_index: u32) {
+        let next_index = self.next_store_index(keychain);
+        if let Some(temp_lookahead) = target_index.checked_sub(next_index).filter(|&v| v > 0) {
+            let old_lookahead = self.lookahead.insert(keychain.clone(), temp_lookahead);
+            self.replenish_lookahead(keychain);
+
+            // revert
+            match old_lookahead {
+                Some(lookahead) => self.lookahead.insert(keychain.clone(), lookahead),
+                None => self.lookahead.remove(keychain),
+            };
+        }
+    }
+
+    fn replenish_lookahead(&mut self, keychain: &K) {
        let descriptor = self.keychains.get(keychain).expect("keychain must exist");
        let next_store_index = self.next_store_index(keychain);
        let next_reveal_index = self.last_revealed.get(keychain).map_or(0, |v| *v + 1);
+        let lookahead = self.lookahead.get(keychain).map_or(0, |v| *v);

-        for (new_index, new_spk) in
-            SpkIterator::new_with_range(descriptor, next_store_index..next_reveal_index + lookahead)
-        {
+        for (new_index, new_spk) in range_descriptor_spks(
+            Cow::Borrowed(descriptor),
+            next_store_index..next_reveal_index + lookahead,
+        ) {
            let _inserted = self
                .inner
                .insert_spk((keychain.clone(), new_index), new_spk);
@@ -359,74 +228,64 @@ impl<K: Clone + Ord + Debug> KeychainTxOutIndex<K> {
    fn next_store_index(&self, keychain: &K) -> u32 {
        self.inner()
            .all_spks()
-            // This range is filtering out the spks with a keychain different than
-            // `keychain`. We don't use filter here as range is more optimized.
            .range((keychain.clone(), u32::MIN)..(keychain.clone(), u32::MAX))
            .last()
-            .map_or(0, |((_, index), _)| *index + 1)
+            .map_or(0, |((_, v), _)| *v + 1)
    }

-    /// Get an unbounded spk iterator over a given `keychain`.
-    ///
-    /// # Panics
-    ///
-    /// This will panic if the given `keychain`'s descriptor does not exist.
-    pub fn unbounded_spk_iter(&self, keychain: &K) -> SpkIterator<Descriptor<DescriptorPublicKey>> {
-        SpkIterator::new(
-            self.keychains
-                .get(keychain)
-                .expect("keychain does not exist")
-                .clone(),
-        )
-    }
-
-    /// Get unbounded spk iterators for all keychains.
-    pub fn all_unbounded_spk_iters(
+    /// Generates script pubkey iterators for every `keychain`. The iterators iterate over all
+    /// derivable script pubkeys.
+    pub fn spks_of_all_keychains(
        &self,
-    ) -> BTreeMap<K, SpkIterator<Descriptor<DescriptorPublicKey>>> {
+    ) -> BTreeMap<K, impl Iterator<Item = (u32, Script)> + Clone> {
        self.keychains
            .iter()
-            .map(|(k, descriptor)| (k.clone(), SpkIterator::new(descriptor.clone())))
+            .map(|(keychain, descriptor)| {
+                (
+                    keychain.clone(),
+                    range_descriptor_spks(Cow::Owned(descriptor.clone()), 0..),
+                )
+            })
            .collect()
    }

-    /// Iterate over revealed spks of all keychains.
-    pub fn revealed_spks(&self) -> impl DoubleEndedIterator<Item = (K, u32, &Script)> + Clone {
-        self.keychains.keys().flat_map(|keychain| {
-            self.revealed_keychain_spks(keychain)
-                .map(|(i, spk)| (keychain.clone(), i, spk))
-        })
+    /// Generates a script pubkey iterator for the given `keychain`'s descriptor (if it exists). The
+    /// iterator iterates over all derivable scripts of the keychain's descriptor.
+    ///
+    /// # Panics
+    ///
+    /// This will panic if the `keychain` does not exist.
+    pub fn spks_of_keychain(&self, keychain: &K) -> impl Iterator<Item = (u32, Script)> + Clone {
+        let descriptor = self
+            .keychains
+            .get(keychain)
+            .expect("keychain must exist")
+            .clone();
+        range_descriptor_spks(Cow::Owned(descriptor), 0..)
    }

-    /// Iterate over revealed spks of the given `keychain`.
-    pub fn revealed_keychain_spks(
+    /// Convenience method to get [`revealed_spks_of_keychain`] of all keychains.
+    ///
+    /// [`revealed_spks_of_keychain`]: Self::revealed_spks_of_keychain
+    pub fn revealed_spks_of_all_keychains(
+        &self,
+    ) -> BTreeMap<K, impl Iterator<Item = (u32, &Script)> + Clone> {
+        self.keychains
+            .keys()
+            .map(|keychain| (keychain.clone(), self.revealed_spks_of_keychain(keychain)))
+            .collect()
+    }
+
+    /// Iterates over the script pubkeys revealed by this index under `keychain`.
+    pub fn revealed_spks_of_keychain(
        &self,
        keychain: &K,
    ) -> impl DoubleEndedIterator<Item = (u32, &Script)> + Clone {
-        let next_i = self.last_revealed.get(keychain).map_or(0, |&i| i + 1);
+        let next_index = self.last_revealed.get(keychain).map_or(0, |v| *v + 1);
        self.inner
            .all_spks()
-            .range((keychain.clone(), u32::MIN)..(keychain.clone(), next_i))
-            .map(|((_, i), spk)| (*i, spk.as_script()))
-    }
-
-    /// Iterate over revealed, but unused, spks of all keychains.
-    pub fn unused_spks(&self) -> impl DoubleEndedIterator<Item = (K, u32, &Script)> + Clone {
-        self.keychains.keys().flat_map(|keychain| {
-            self.unused_keychain_spks(keychain)
-                .map(|(i, spk)| (keychain.clone(), i, spk))
-        })
-    }
-
-    /// Iterate over revealed, but unused, spks of the given `keychain`.
-    pub fn unused_keychain_spks(
-        &self,
-        keychain: &K,
-    ) -> impl DoubleEndedIterator<Item = (u32, &Script)> + Clone {
-        let next_i = self.last_revealed.get(keychain).map_or(0, |&i| i + 1);
-        self.inner
-            .unused_spks((keychain.clone(), u32::MIN)..(keychain.clone(), next_i))
-            .map(|((_, i), spk)| (*i, spk))
+            .range((keychain.clone(), u32::MIN)..(keychain.clone(), next_index))
+            .map(|((_, derivation_index), spk)| (*derivation_index, spk))
    }

    /// Get the next derivation index for `keychain`. The next index is the index after the last revealed
@@ -482,21 +341,21 @@ impl<K: Clone + Ord + Debug> KeychainTxOutIndex<K> {
        &mut self,
        keychains: &BTreeMap<K, u32>,
    ) -> (
-        BTreeMap<K, SpkIterator<Descriptor<DescriptorPublicKey>>>,
-        super::ChangeSet<K>,
+        BTreeMap<K, impl Iterator<Item = (u32, Script)>>,
+        DerivationAdditions<K>,
    ) {
-        let mut changeset = super::ChangeSet::default();
+        let mut additions = DerivationAdditions::default();
        let mut spks = BTreeMap::new();

        for (keychain, &index) in keychains {
-            let (new_spks, new_changeset) = self.reveal_to_target(keychain, index);
-            if !new_changeset.is_empty() {
+            let (new_spks, new_additions) = self.reveal_to_target(keychain, index);
+            if !new_additions.is_empty() {
                spks.insert(keychain.clone(), new_spks);
-                changeset.append(new_changeset.clone());
+                additions.append(new_additions);
            }
        }

-        (spks, changeset)
+        (spks, additions)
    }

    /// Reveals script pubkeys of the `keychain`'s descriptor **up to and including** the
@@ -507,7 +366,7 @@ impl<K: Clone + Ord + Debug> KeychainTxOutIndex<K> {
    /// reveal up to the last possible index.
    ///
    /// This returns an iterator of newly revealed indices (alongside their scripts) and a
-    /// [`super::ChangeSet`], which reports updates to the latest revealed index. If no new script
+    /// [`DerivationAdditions`], which reports updates to the latest revealed index. If no new script
    /// pubkeys are revealed, then both of these will be empty.
    ///
    /// # Panics
@@ -517,62 +376,72 @@ impl<K: Clone + Ord + Debug> KeychainTxOutIndex<K> {
        &mut self,
        keychain: &K,
        target_index: u32,
-    ) -> (
-        SpkIterator<Descriptor<DescriptorPublicKey>>,
-        super::ChangeSet<K>,
-    ) {
+    ) -> (impl Iterator<Item = (u32, Script)>, DerivationAdditions<K>) {
        let descriptor = self.keychains.get(keychain).expect("keychain must exist");
        let has_wildcard = descriptor.has_wildcard();

        let target_index = if has_wildcard { target_index } else { 0 };
-        let next_reveal_index = self
-            .last_revealed
-            .get(keychain)
-            .map_or(0, |index| *index + 1);
+        let next_reveal_index = self.last_revealed.get(keychain).map_or(0, |v| *v + 1);
+        let lookahead = self.lookahead.get(keychain).map_or(0, |v| *v);

-        debug_assert!(next_reveal_index + self.lookahead >= self.next_store_index(keychain));
+        debug_assert_eq!(
+            next_reveal_index + lookahead,
+            self.next_store_index(keychain)
+        );

-        // If the target_index is already revealed, we are done
-        if next_reveal_index > target_index {
-            return (
-                SpkIterator::new_with_range(
-                    descriptor.clone(),
-                    next_reveal_index..next_reveal_index,
-                ),
-                super::ChangeSet::default(),
-            );
+        // if we need to reveal new indices, the latest revealed index goes here
+        let mut reveal_to_index = None;
+
+        // if the target is not yet revealed, but is already stored (due to lookahead), we need to
+        // set the `reveal_to_index` as target here (as the `for` loop below only updates
+        // `reveal_to_index` for indexes that are NOT stored)
+        if next_reveal_index <= target_index && target_index < next_reveal_index + lookahead {
+            reveal_to_index = Some(target_index);
        }

-        // We range over the indexes that are not stored and insert their spks in the index.
-        // Indexes from next_reveal_index to next_reveal_index + lookahead are already stored (due
-        // to lookahead), so we only range from next_reveal_index + lookahead to target + lookahead
-        let range = next_reveal_index + self.lookahead..=target_index + self.lookahead;
-        for (new_index, new_spk) in SpkIterator::new_with_range(descriptor, range) {
+        // we range over indexes that are not stored
+        let range = next_reveal_index + lookahead..=target_index + lookahead;
+        for (new_index, new_spk) in range_descriptor_spks(Cow::Borrowed(descriptor), range) {
            let _inserted = self
                .inner
                .insert_spk((keychain.clone(), new_index), new_spk);
-            debug_assert!(_inserted, "must not have existing spk");
-            debug_assert!(
-                has_wildcard || new_index == 0,
-                "non-wildcard descriptors must not iterate past index 0"
-            );
+            debug_assert!(_inserted, "must not have existing spk",);
+
+            // everything after `target_index` is stored for lookahead only
+            if new_index <= target_index {
+                reveal_to_index = Some(new_index);
+            }
        }

-        let _old_index = self.last_revealed.insert(keychain.clone(), target_index);
-        debug_assert!(_old_index < Some(target_index));
-        (
-            SpkIterator::new_with_range(descriptor.clone(), next_reveal_index..target_index + 1),
-            super::ChangeSet(core::iter::once((keychain.clone(), target_index)).collect()),
-        )
+        match reveal_to_index {
+            Some(index) => {
+                let _old_index = self.last_revealed.insert(keychain.clone(), index);
+                debug_assert!(_old_index < Some(index));
+                (
+                    range_descriptor_spks(
+                        Cow::Owned(descriptor.clone()),
+                        next_reveal_index..index + 1,
+                    ),
+                    DerivationAdditions(core::iter::once((keychain.clone(), index)).collect()),
+                )
+            }
+            None => (
+                range_descriptor_spks(
+                    Cow::Owned(descriptor.clone()),
+                    next_reveal_index..next_reveal_index,
+                ),
+                DerivationAdditions::default(),
+            ),
+        }
    }

    /// Attempts to reveal the next script pubkey for `keychain`.
    ///
    /// Returns the derivation index of the revealed script pubkey, the revealed script pubkey and a
-    /// [`super::ChangeSet`] which represents changes in the last revealed index (if any).
+    /// [`DerivationAdditions`] which represents changes in the last revealed index (if any).
    ///
    /// When a new script cannot be revealed, we return the last revealed script and an empty
-    /// [`super::ChangeSet`]. There are two scenarios when a new script pubkey cannot be derived:
+    /// [`DerivationAdditions`]. There are two scenarios when a new script pubkey cannot be derived:
    ///
    ///  1. The descriptor has no wildcard and already has one script revealed.
    ///  2. The descriptor has already revealed scripts up to the numeric bound.
@@ -580,14 +449,14 @@ impl<K: Clone + Ord + Debug> KeychainTxOutIndex<K> {
    /// # Panics
    ///
    /// Panics if the `keychain` does not exist.
-    pub fn reveal_next_spk(&mut self, keychain: &K) -> ((u32, &Script), super::ChangeSet<K>) {
+    pub fn reveal_next_spk(&mut self, keychain: &K) -> ((u32, &Script), DerivationAdditions<K>) {
        let (next_index, _) = self.next_index(keychain);
-        let changeset = self.reveal_to_target(keychain, next_index).1;
+        let additions = self.reveal_to_target(keychain, next_index).1;
        let script = self
            .inner
            .spk_at_index(&(keychain.clone(), next_index))
            .expect("script must already be stored");
-        ((next_index, script), changeset)
+        ((next_index, script), additions)
    }

    /// Gets the next unused script pubkey in the keychain. I.e., the script pubkey with the lowest
@@ -602,59 +471,73 @@ impl<K: Clone + Ord + Debug> KeychainTxOutIndex<K> {
    /// # Panics
    ///
    /// Panics if `keychain` has never been added to the index
-    pub fn next_unused_spk(&mut self, keychain: &K) -> ((u32, &Script), super::ChangeSet<K>) {
-        let need_new = self.unused_keychain_spks(keychain).next().is_none();
+    pub fn next_unused_spk(&mut self, keychain: &K) -> ((u32, &Script), DerivationAdditions<K>) {
+        let need_new = self.unused_spks_of_keychain(keychain).next().is_none();
        // this rather strange branch is needed because of some lifetime issues
        if need_new {
            self.reveal_next_spk(keychain)
        } else {
            (
-                self.unused_keychain_spks(keychain)
+                self.unused_spks_of_keychain(keychain)
                    .next()
                    .expect("we already know next exists"),
-                super::ChangeSet::default(),
+                DerivationAdditions::default(),
            )
        }
    }

-    /// Iterate over all [`OutPoint`]s that point to `TxOut`s with script pubkeys derived from
-    /// `keychain`.
+    /// Marks the script pubkey at `index` as used even though the tracker hasn't seen an output with it.
+    /// This only has an effect when the `index` had been added to `self` already and was unused.
    ///
-    /// Use [`keychain_outpoints_in_range`](KeychainTxOutIndex::keychain_outpoints_in_range) to
-    /// iterate over a specific derivation range.
-    pub fn keychain_outpoints(
-        &self,
-        keychain: &K,
-    ) -> impl DoubleEndedIterator<Item = (u32, OutPoint)> + '_ {
-        self.keychain_outpoints_in_range(keychain, ..)
+    /// Returns whether the `index` was initially present as `unused`.
+    ///
+    /// This is useful when you want to reserve a script pubkey for something but don't want to add
+    /// the transaction output using it to the index yet. Other callers will consider `index` on
+    /// `keychain` used until you call [`unmark_used`].
+    ///
+    /// [`unmark_used`]: Self::unmark_used
+    pub fn mark_used(&mut self, keychain: &K, index: u32) -> bool {
+        self.inner.mark_used(&(keychain.clone(), index))
    }

-    /// Iterate over [`OutPoint`]s that point to `TxOut`s with script pubkeys derived from
-    /// `keychain` in a given derivation `range`.
-    pub fn keychain_outpoints_in_range(
+    /// Undoes the effect of [`mark_used`]. Returns whether the `index` is inserted back into
+    /// `unused`.
+    ///
+    /// Note that if `self` has scanned an output with this script pubkey, then this will have no
+    /// effect.
+    ///
+    /// [`mark_used`]: Self::mark_used
+    pub fn unmark_used(&mut self, keychain: &K, index: u32) -> bool {
+        self.inner.unmark_used(&(keychain.clone(), index))
+    }
+
+    /// Iterates over all unused script pubkeys for a `keychain` stored in the index.
+    pub fn unused_spks_of_keychain(
        &self,
        keychain: &K,
-        range: impl RangeBounds<u32>,
-    ) -> impl DoubleEndedIterator<Item = (u32, OutPoint)> + '_ {
-        let start = match range.start_bound() {
-            Bound::Included(i) => Bound::Included((keychain.clone(), *i)),
-            Bound::Excluded(i) => Bound::Excluded((keychain.clone(), *i)),
-            Bound::Unbounded => Bound::Unbounded,
-        };
-        let end = match range.end_bound() {
-            Bound::Included(i) => Bound::Included((keychain.clone(), *i)),
-            Bound::Excluded(i) => Bound::Excluded((keychain.clone(), *i)),
-            Bound::Unbounded => Bound::Unbounded,
-        };
+    ) -> impl DoubleEndedIterator<Item = (u32, &Script)> {
+        let next_index = self.last_revealed.get(keychain).map_or(0, |&v| v + 1);
+        let range = (keychain.clone(), u32::MIN)..(keychain.clone(), next_index);
        self.inner
-            .outputs_in_range((start, end))
+            .unused_spks(range)
+            .map(|((_, i), script)| (*i, script))
+    }
+
+    /// Iterates over all the [`OutPoint`] that have a `TxOut` with a script pubkey derived from
+    /// `keychain`.
+    pub fn txouts_of_keychain(
+        &self,
+        keychain: &K,
+    ) -> impl DoubleEndedIterator<Item = (u32, OutPoint)> + '_ {
+        self.inner
+            .outputs_in_range((keychain.clone(), u32::MIN)..(keychain.clone(), u32::MAX))
            .map(|((_, i), op)| (*i, op))
    }

    /// Returns the highest derivation index of the `keychain` where [`KeychainTxOutIndex`] has
    /// found a [`TxOut`] with it's script pubkey.
    pub fn last_used_index(&self, keychain: &K) -> Option<u32> {
-        self.keychain_outpoints(keychain).last().map(|(i, _)| i)
+        self.txouts_of_keychain(keychain).last().map(|(i, _)| i)
    }

    /// Returns the highest derivation index of each keychain that [`KeychainTxOutIndex`] has found
@@ -669,9 +552,39 @@ impl<K: Clone + Ord + Debug> KeychainTxOutIndex<K> {
            .collect()
    }

-    /// Applies the derivation changeset to the [`KeychainTxOutIndex`], extending the number of
-    /// derived scripts per keychain, as specified in the `changeset`.
-    pub fn apply_changeset(&mut self, changeset: super::ChangeSet<K>) {
-        let _ = self.reveal_to_target_multi(&changeset.0);
+    /// Applies the derivation additions to the [`KeychainTxOutIndex`], extending the number of
+    /// derived scripts per keychain, as specified in the `additions`.
+    pub fn apply_additions(&mut self, additions: DerivationAdditions<K>) {
+        let _ = self.reveal_to_target_multi(&additions.0);
    }
 }
+
+fn range_descriptor_spks<'a, R>(
+    descriptor: Cow<'a, Descriptor<DescriptorPublicKey>>,
+    range: R,
+) -> impl Iterator<Item = (u32, Script)> + Clone + Send + 'a
+where
+    R: Iterator<Item = u32> + Clone + Send + 'a,
+{
+    let secp = Secp256k1::verification_only();
+    let has_wildcard = descriptor.has_wildcard();
+    range
+        .into_iter()
+        // non-wildcard descriptors can only have one derivation index (0)
+        .take_while(move |&index| has_wildcard || index == 0)
+        // we can only iterate over non-hardened indices
+        .take_while(|&index| index <= BIP32_MAX_INDEX)
+        .map(
+            move |index| -> Result<_, miniscript::descriptor::ConversionError> {
+                Ok((
+                    index,
+                    descriptor
+                        .at_derivation_index(index)
+                        .derived_descriptor(&secp)?
+                        .script_pubkey(),
+                ))
+            },
+        )
+        .take_while(Result::is_ok)
+        .map(Result::unwrap)
+}
--- a/crates/chain/src/lib.rs
+++ b/crates/chain/src/lib.rs
@@ -1,4 +1,4 @@
-//! This crate is a collection of core structures for [Bitcoin Dev Kit].
+//! This crate is a collection of core structures for [Bitcoin Dev Kit] (alpha release).
 //!
 //! The goal of this crate is to give wallets the mechanisms needed to:
 //!
@@ -12,31 +12,23 @@
 //!    you do it synchronously or asynchronously. If you know a fact about the blockchain, you can just
 //!    tell `bdk_chain`'s APIs about it, and that information will be integrated, if it can be done
 //!    consistently.
-//! 2. Data persistence agnostic -- `bdk_chain` does not care where you cache on-chain data, what you
-//!    cache or how you retrieve it from persistent storage.
+//! 2. Error-free APIs.
+//! 3. Data persistence agnostic -- `bdk_chain` does not care where you cache on-chain data, what you
+//!    cache or how you fetch it.
 //!
 //! [Bitcoin Dev Kit]: https://bitcoindevkit.org/
-
 #![no_std]
-#![warn(missing_docs)]
-
 pub use bitcoin;
+pub mod chain_graph;
 mod spk_txout_index;
 pub use spk_txout_index::*;
 mod chain_data;
 pub use chain_data::*;
-pub mod indexed_tx_graph;
-pub use indexed_tx_graph::IndexedTxGraph;
 pub mod keychain;
-pub mod local_chain;
+pub mod sparse_chain;
 mod tx_data_traits;
 pub mod tx_graph;
 pub use tx_data_traits::*;
-pub use tx_graph::TxGraph;
-mod chain_oracle;
-pub use chain_oracle::*;
-mod persist;
-pub use persist::*;

 #[doc(hidden)]
 pub mod example_utils;
@@ -47,10 +39,6 @@ pub use miniscript;
 mod descriptor_ext;
 #[cfg(feature = "miniscript")]
 pub use descriptor_ext::DescriptorExt;
-#[cfg(feature = "miniscript")]
-mod spk_iter;
-#[cfg(feature = "miniscript")]
-pub use spk_iter::*;

 #[allow(unused_imports)]
 #[macro_use]
--- a/crates/chain/src/local_chain.rs
+++ b/crates/chain/src/local_chain.rs
@@ -1,836 +0,0 @@
-//! The [`LocalChain`] is a local implementation of [`ChainOracle`].
-
-use core::convert::Infallible;
-use core::ops::RangeBounds;
-
-use crate::collections::BTreeMap;
-use crate::{BlockId, ChainOracle};
-use alloc::sync::Arc;
-use bitcoin::block::Header;
-use bitcoin::BlockHash;
-
-/// The [`ChangeSet`] represents changes to [`LocalChain`].
-///
-/// The key represents the block height, and the value either represents added a new [`CheckPoint`]
-/// (if [`Some`]), or removing a [`CheckPoint`] (if [`None`]).
-pub type ChangeSet = BTreeMap<u32, Option<BlockHash>>;
-
-/// A [`LocalChain`] checkpoint is used to find the agreement point between two chains and as a
-/// transaction anchor.
-///
-/// Each checkpoint contains the height and hash of a block ([`BlockId`]).
-///
-/// Internally, checkpoints are nodes of a reference-counted linked-list. This allows the caller to
-/// cheaply clone a [`CheckPoint`] without copying the whole list and to view the entire chain
-/// without holding a lock on [`LocalChain`].
-#[derive(Debug, Clone)]
-pub struct CheckPoint(Arc<CPInner>);
-
-/// The internal contents of [`CheckPoint`].
-#[derive(Debug, Clone)]
-struct CPInner {
-    /// Block id (hash and height).
-    block: BlockId,
-    /// Previous checkpoint (if any).
-    prev: Option<Arc<CPInner>>,
-}
-
-impl PartialEq for CheckPoint {
-    fn eq(&self, other: &Self) -> bool {
-        let self_cps = self.iter().map(|cp| cp.block_id());
-        let other_cps = other.iter().map(|cp| cp.block_id());
-        self_cps.eq(other_cps)
-    }
-}
-
-impl CheckPoint {
-    /// Construct a new base block at the front of a linked list.
-    pub fn new(block: BlockId) -> Self {
-        Self(Arc::new(CPInner { block, prev: None }))
-    }
-
-    /// Construct a checkpoint from a list of [`BlockId`]s in ascending height order.
-    ///
-    /// # Errors
-    ///
-    /// This method will error if any of the follow occurs:
-    ///
-    /// - The `blocks` iterator is empty, in which case, the error will be `None`.
-    /// - The `blocks` iterator is not in ascending height order.
-    /// - The `blocks` iterator contains multiple [`BlockId`]s of the same height.
-    ///
-    /// The error type is the last successful checkpoint constructed (if any).
-    pub fn from_block_ids(
-        block_ids: impl IntoIterator<Item = BlockId>,
-    ) -> Result<Self, Option<Self>> {
-        let mut blocks = block_ids.into_iter();
-        let mut acc = CheckPoint::new(blocks.next().ok_or(None)?);
-        for id in blocks {
-            acc = acc.push(id).map_err(Some)?;
-        }
-        Ok(acc)
-    }
-
-    /// Construct a checkpoint from the given `header` and block `height`.
-    ///
-    /// If `header` is of the genesis block, the checkpoint won't have a [`prev`] node. Otherwise,
-    /// we return a checkpoint linked with the previous block.
-    ///
-    /// [`prev`]: CheckPoint::prev
-    pub fn from_header(header: &bitcoin::block::Header, height: u32) -> Self {
-        let hash = header.block_hash();
-        let this_block_id = BlockId { height, hash };
-
-        let prev_height = match height.checked_sub(1) {
-            Some(h) => h,
-            None => return Self::new(this_block_id),
-        };
-
-        let prev_block_id = BlockId {
-            height: prev_height,
-            hash: header.prev_blockhash,
-        };
-
-        CheckPoint::new(prev_block_id)
-            .push(this_block_id)
-            .expect("must construct checkpoint")
-    }
-
-    /// Convenience method to convert the [`CheckPoint`] into an [`Update`].
-    ///
-    /// For more information, refer to [`Update`].
-    pub fn into_update(self, introduce_older_blocks: bool) -> Update {
-        Update {
-            tip: self,
-            introduce_older_blocks,
-        }
-    }
-
-    /// Puts another checkpoint onto the linked list representing the blockchain.
-    ///
-    /// Returns an `Err(self)` if the block you are pushing on is not at a greater height that the one you
-    /// are pushing on to.
-    pub fn push(self, block: BlockId) -> Result<Self, Self> {
-        if self.height() < block.height {
-            Ok(Self(Arc::new(CPInner {
-                block,
-                prev: Some(self.0),
-            })))
-        } else {
-            Err(self)
-        }
-    }
-
-    /// Extends the checkpoint linked list by a iterator of block ids.
-    ///
-    /// Returns an `Err(self)` if there is block which does not have a greater height than the
-    /// previous one.
-    pub fn extend(self, blocks: impl IntoIterator<Item = BlockId>) -> Result<Self, Self> {
-        let mut curr = self.clone();
-        for block in blocks {
-            curr = curr.push(block).map_err(|_| self.clone())?;
-        }
-        Ok(curr)
-    }
-
-    /// Get the [`BlockId`] of the checkpoint.
-    pub fn block_id(&self) -> BlockId {
-        self.0.block
-    }
-
-    /// Get the height of the checkpoint.
-    pub fn height(&self) -> u32 {
-        self.0.block.height
-    }
-
-    /// Get the block hash of the checkpoint.
-    pub fn hash(&self) -> BlockHash {
-        self.0.block.hash
-    }
-
-    /// Get the previous checkpoint in the chain
-    pub fn prev(&self) -> Option<CheckPoint> {
-        self.0.prev.clone().map(CheckPoint)
-    }
-
-    /// Iterate from this checkpoint in descending height.
-    pub fn iter(&self) -> CheckPointIter {
-        self.clone().into_iter()
-    }
-
-    /// Get checkpoint at `height`.
-    ///
-    /// Returns `None` if checkpoint at `height` does not exist`.
-    pub fn get(&self, height: u32) -> Option<Self> {
-        self.range(height..=height).next()
-    }
-
-    /// Iterate checkpoints over a height range.
-    ///
-    /// Note that we always iterate checkpoints in reverse height order (iteration starts at tip
-    /// height).
-    pub fn range<R>(&self, range: R) -> impl Iterator<Item = CheckPoint>
-    where
-        R: RangeBounds<u32>,
-    {
-        let start_bound = range.start_bound().cloned();
-        let end_bound = range.end_bound().cloned();
-        self.iter()
-            .skip_while(move |cp| match end_bound {
-                core::ops::Bound::Included(inc_bound) => cp.height() > inc_bound,
-                core::ops::Bound::Excluded(exc_bound) => cp.height() >= exc_bound,
-                core::ops::Bound::Unbounded => false,
-            })
-            .take_while(move |cp| match start_bound {
-                core::ops::Bound::Included(inc_bound) => cp.height() >= inc_bound,
-                core::ops::Bound::Excluded(exc_bound) => cp.height() > exc_bound,
-                core::ops::Bound::Unbounded => true,
-            })
-    }
-}
-
-/// Iterates over checkpoints backwards.
-pub struct CheckPointIter {
-    current: Option<Arc<CPInner>>,
-}
-
-impl Iterator for CheckPointIter {
-    type Item = CheckPoint;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        let current = self.current.clone()?;
-        self.current = current.prev.clone();
-        Some(CheckPoint(current))
-    }
-}
-
-impl IntoIterator for CheckPoint {
-    type Item = CheckPoint;
-    type IntoIter = CheckPointIter;
-
-    fn into_iter(self) -> Self::IntoIter {
-        CheckPointIter {
-            current: Some(self.0),
-        }
-    }
-}
-
-/// Used to update [`LocalChain`].
-///
-/// This is used as input for [`LocalChain::apply_update`]. It contains the update's chain `tip` and
-/// a flag `introduce_older_blocks` which signals whether this update intends to introduce missing
-/// blocks to the original chain.
-///
-/// Block-by-block syncing mechanisms would typically create updates that builds upon the previous
-/// tip. In this case, `introduce_older_blocks` would be `false`.
-///
-/// Script-pubkey based syncing mechanisms may not introduce transactions in a chronological order
-/// so some updates require introducing older blocks (to anchor older transactions). For
-/// script-pubkey based syncing, `introduce_older_blocks` would typically be `true`.
-#[derive(Debug, Clone, PartialEq)]
-pub struct Update {
-    /// The update chain's new tip.
-    pub tip: CheckPoint,
-
-    /// Whether the update allows for introducing older blocks.
-    ///
-    /// Refer to [struct-level documentation] for more.
-    ///
-    /// [struct-level documentation]: Update
-    pub introduce_older_blocks: bool,
-}
-
-/// This is a local implementation of [`ChainOracle`].
-#[derive(Debug, Clone, PartialEq)]
-pub struct LocalChain {
-    tip: CheckPoint,
-}
-
-impl ChainOracle for LocalChain {
-    type Error = Infallible;
-
-    fn is_block_in_chain(
-        &self,
-        block: BlockId,
-        chain_tip: BlockId,
-    ) -> Result<Option<bool>, Self::Error> {
-        let chain_tip_cp = match self.tip.get(chain_tip.height) {
-            // we can only determine whether `block` is in chain of `chain_tip` if `chain_tip` can
-            // be identified in chain
-            Some(cp) if cp.hash() == chain_tip.hash => cp,
-            _ => return Ok(None),
-        };
-        match chain_tip_cp.get(block.height) {
-            Some(cp) => Ok(Some(cp.hash() == block.hash)),
-            None => Ok(None),
-        }
-    }
-
-    fn get_chain_tip(&self) -> Result<BlockId, Self::Error> {
-        Ok(self.tip.block_id())
-    }
-}
-
-impl LocalChain {
-    /// Get the genesis hash.
-    pub fn genesis_hash(&self) -> BlockHash {
-        self.tip.get(0).expect("genesis must exist").hash()
-    }
-
-    /// Construct [`LocalChain`] from genesis `hash`.
-    #[must_use]
-    pub fn from_genesis_hash(hash: BlockHash) -> (Self, ChangeSet) {
-        let height = 0;
-        let chain = Self {
-            tip: CheckPoint::new(BlockId { height, hash }),
-        };
-        let changeset = chain.initial_changeset();
-        (chain, changeset)
-    }
-
-    /// Construct a [`LocalChain`] from an initial `changeset`.
-    pub fn from_changeset(changeset: ChangeSet) -> Result<Self, MissingGenesisError> {
-        let genesis_entry = changeset.get(&0).copied().flatten();
-        let genesis_hash = match genesis_entry {
-            Some(hash) => hash,
-            None => return Err(MissingGenesisError),
-        };
-
-        let (mut chain, _) = Self::from_genesis_hash(genesis_hash);
-        chain.apply_changeset(&changeset)?;
-
-        debug_assert!(chain._check_changeset_is_applied(&changeset));
-
-        Ok(chain)
-    }
-
-    /// Construct a [`LocalChain`] from a given `checkpoint` tip.
-    pub fn from_tip(tip: CheckPoint) -> Result<Self, MissingGenesisError> {
-        let genesis_cp = tip.iter().last().expect("must have at least one element");
-        if genesis_cp.height() != 0 {
-            return Err(MissingGenesisError);
-        }
-        Ok(Self { tip })
-    }
-
-    /// Constructs a [`LocalChain`] from a [`BTreeMap`] of height to [`BlockHash`].
-    ///
-    /// The [`BTreeMap`] enforces the height order. However, the caller must ensure the blocks are
-    /// all of the same chain.
-    pub fn from_blocks(blocks: BTreeMap<u32, BlockHash>) -> Result<Self, MissingGenesisError> {
-        if blocks.get(&0).is_none() {
-            return Err(MissingGenesisError);
-        }
-
-        let mut tip: Option<CheckPoint> = None;
-        for block in &blocks {
-            match tip {
-                Some(curr) => {
-                    tip = Some(
-                        curr.push(BlockId::from(block))
-                            .expect("BTreeMap is ordered"),
-                    )
-                }
-                None => tip = Some(CheckPoint::new(BlockId::from(block))),
-            }
-        }
-
-        Ok(Self {
-            tip: tip.expect("already checked to have genesis"),
-        })
-    }
-
-    /// Get the highest checkpoint.
-    pub fn tip(&self) -> CheckPoint {
-        self.tip.clone()
-    }
-
-    /// Applies the given `update` to the chain.
-    ///
-    /// The method returns [`ChangeSet`] on success. This represents the applied changes to `self`.
-    ///
-    /// There must be no ambiguity about which of the existing chain's blocks are still valid and
-    /// which are now invalid. That is, the new chain must implicitly connect to a definite block in
-    /// the existing chain and invalidate the block after it (if it exists) by including a block at
-    /// the same height but with a different hash to explicitly exclude it as a connection point.
-    ///
-    /// Additionally, an empty chain can be updated with any chain, and a chain with a single block
-    /// can have it's block invalidated by an update chain with a block at the same height but
-    /// different hash.
-    ///
-    /// # Errors
-    ///
-    /// An error will occur if the update does not correctly connect with `self`.
-    ///
-    /// Refer to [`Update`] for more about the update struct.
-    ///
-    /// [module-level documentation]: crate::local_chain
-    pub fn apply_update(&mut self, update: Update) -> Result<ChangeSet, CannotConnectError> {
-        let changeset = merge_chains(
-            self.tip.clone(),
-            update.tip.clone(),
-            update.introduce_older_blocks,
-        )?;
-        // `._check_index_is_consistent_with_tip` and `._check_changeset_is_applied` is called in
-        // `.apply_changeset`
-        self.apply_changeset(&changeset)
-            .map_err(|_| CannotConnectError {
-                try_include_height: 0,
-            })?;
-        Ok(changeset)
-    }
-
-    /// Update the chain with a given [`Header`] at `height` which you claim is connected to a existing block in the chain.
-    ///
-    /// This is useful when you have a block header that you want to record as part of the chain but
-    /// don't necessarily know that the `prev_blockhash` is in the chain.
-    ///
-    /// This will usually insert two new [`BlockId`]s into the chain: the header's block and the
-    /// header's `prev_blockhash` block. `connected_to` must already be in the chain but is allowed
-    /// to be `prev_blockhash` (in which case only one new block id will be inserted).
-    /// To be successful, `connected_to` must be chosen carefully so that `LocalChain`'s [update
-    /// rules][`apply_update`] are satisfied.
-    ///
-    /// # Errors
-    ///
-    /// [`ApplyHeaderError::InconsistentBlocks`] occurs if the `connected_to` block and the
-    /// [`Header`] is inconsistent. For example, if the `connected_to` block is the same height as
-    /// `header` or `prev_blockhash`, but has a different block hash. Or if the `connected_to`
-    /// height is greater than the header's `height`.
-    ///
-    /// [`ApplyHeaderError::CannotConnect`] occurs if the internal call to [`apply_update`] fails.
-    ///
-    /// [`apply_update`]: Self::apply_update
-    pub fn apply_header_connected_to(
-        &mut self,
-        header: &Header,
-        height: u32,
-        connected_to: BlockId,
-    ) -> Result<ChangeSet, ApplyHeaderError> {
-        let this = BlockId {
-            height,
-            hash: header.block_hash(),
-        };
-        let prev = height.checked_sub(1).map(|prev_height| BlockId {
-            height: prev_height,
-            hash: header.prev_blockhash,
-        });
-        let conn = match connected_to {
-            // `connected_to` can be ignored if same as `this` or `prev` (duplicate)
-            conn if conn == this || Some(conn) == prev => None,
-            // this occurs if:
-            // - `connected_to` height is the same as `prev`, but different hash
-            // - `connected_to` height is the same as `this`, but different hash
-            // - `connected_to` height is greater than `this` (this is not allowed)
-            conn if conn.height >= height.saturating_sub(1) => {
-                return Err(ApplyHeaderError::InconsistentBlocks)
-            }
-            conn => Some(conn),
-        };
-
-        let update = Update {
-            tip: CheckPoint::from_block_ids([conn, prev, Some(this)].into_iter().flatten())
-                .expect("block ids must be in order"),
-            introduce_older_blocks: false,
-        };
-
-        self.apply_update(update)
-            .map_err(ApplyHeaderError::CannotConnect)
-    }
-
-    /// Update the chain with a given [`Header`] connecting it with the previous block.
-    ///
-    /// This is a convenience method to call [`apply_header_connected_to`] with the `connected_to`
-    /// parameter being `height-1:prev_blockhash`. If there is no previous block (i.e. genesis), we
-    /// use the current block as `connected_to`.
-    ///
-    /// [`apply_header_connected_to`]: LocalChain::apply_header_connected_to
-    pub fn apply_header(
-        &mut self,
-        header: &Header,
-        height: u32,
-    ) -> Result<ChangeSet, CannotConnectError> {
-        let connected_to = match height.checked_sub(1) {
-            Some(prev_height) => BlockId {
-                height: prev_height,
-                hash: header.prev_blockhash,
-            },
-            None => BlockId {
-                height,
-                hash: header.block_hash(),
-            },
-        };
-        self.apply_header_connected_to(header, height, connected_to)
-            .map_err(|err| match err {
-                ApplyHeaderError::InconsistentBlocks => {
-                    unreachable!("connected_to is derived from the block so is always consistent")
-                }
-                ApplyHeaderError::CannotConnect(err) => err,
-            })
-    }
-
-    /// Apply the given `changeset`.
-    pub fn apply_changeset(&mut self, changeset: &ChangeSet) -> Result<(), MissingGenesisError> {
-        if let Some(start_height) = changeset.keys().next().cloned() {
-            // changes after point of agreement
-            let mut extension = BTreeMap::default();
-            // point of agreement
-            let mut base: Option<CheckPoint> = None;
-
-            for cp in self.iter_checkpoints() {
-                if cp.height() >= start_height {
-                    extension.insert(cp.height(), cp.hash());
-                } else {
-                    base = Some(cp);
-                    break;
-                }
-            }
-
-            for (&height, &hash) in changeset {
-                match hash {
-                    Some(hash) => {
-                        extension.insert(height, hash);
-                    }
-                    None => {
-                        extension.remove(&height);
-                    }
-                };
-            }
-
-            let new_tip = match base {
-                Some(base) => base
-                    .extend(extension.into_iter().map(BlockId::from))
-                    .expect("extension is strictly greater than base"),
-                None => LocalChain::from_blocks(extension)?.tip(),
-            };
-            self.tip = new_tip;
-
-            debug_assert!(self._check_changeset_is_applied(changeset));
-        }
-
-        Ok(())
-    }
-
-    /// Insert a [`BlockId`].
-    ///
-    /// # Errors
-    ///
-    /// Replacing the block hash of an existing checkpoint will result in an error.
-    pub fn insert_block(&mut self, block_id: BlockId) -> Result<ChangeSet, AlterCheckPointError> {
-        if let Some(original_cp) = self.tip.get(block_id.height) {
-            let original_hash = original_cp.hash();
-            if original_hash != block_id.hash {
-                return Err(AlterCheckPointError {
-                    height: block_id.height,
-                    original_hash,
-                    update_hash: Some(block_id.hash),
-                });
-            }
-            return Ok(ChangeSet::default());
-        }
-
-        let mut changeset = ChangeSet::default();
-        changeset.insert(block_id.height, Some(block_id.hash));
-        self.apply_changeset(&changeset)
-            .map_err(|_| AlterCheckPointError {
-                height: 0,
-                original_hash: self.genesis_hash(),
-                update_hash: changeset.get(&0).cloned().flatten(),
-            })?;
-        Ok(changeset)
-    }
-
-    /// Removes blocks from (and inclusive of) the given `block_id`.
-    ///
-    /// This will remove blocks with a height equal or greater than `block_id`, but only if
-    /// `block_id` exists in the chain.
-    ///
-    /// # Errors
-    ///
-    /// This will fail with [`MissingGenesisError`] if the caller attempts to disconnect from the
-    /// genesis block.
-    pub fn disconnect_from(&mut self, block_id: BlockId) -> Result<ChangeSet, MissingGenesisError> {
-        let mut remove_from = Option::<CheckPoint>::None;
-        let mut changeset = ChangeSet::default();
-        for cp in self.tip().iter() {
-            let cp_id = cp.block_id();
-            if cp_id.height < block_id.height {
-                break;
-            }
-            changeset.insert(cp_id.height, None);
-            if cp_id == block_id {
-                remove_from = Some(cp);
-            }
-        }
-        self.tip = match remove_from.map(|cp| cp.prev()) {
-            // The checkpoint below the earliest checkpoint to remove will be the new tip.
-            Some(Some(new_tip)) => new_tip,
-            // If there is no checkpoint below the earliest checkpoint to remove, it means the
-            // "earliest checkpoint to remove" is the genesis block. We disallow removing the
-            // genesis block.
-            Some(None) => return Err(MissingGenesisError),
-            // If there is nothing to remove, we return an empty changeset.
-            None => return Ok(ChangeSet::default()),
-        };
-        Ok(changeset)
-    }
-
-    /// Derives an initial [`ChangeSet`], meaning that it can be applied to an empty chain to
-    /// recover the current chain.
-    pub fn initial_changeset(&self) -> ChangeSet {
-        self.tip
-            .iter()
-            .map(|cp| {
-                let block_id = cp.block_id();
-                (block_id.height, Some(block_id.hash))
-            })
-            .collect()
-    }
-
-    /// Iterate over checkpoints in descending height order.
-    pub fn iter_checkpoints(&self) -> CheckPointIter {
-        CheckPointIter {
-            current: Some(self.tip.0.clone()),
-        }
-    }
-
-    fn _check_changeset_is_applied(&self, changeset: &ChangeSet) -> bool {
-        let mut curr_cp = self.tip.clone();
-        for (height, exp_hash) in changeset.iter().rev() {
-            match curr_cp.get(*height) {
-                Some(query_cp) => {
-                    if query_cp.height() != *height || Some(query_cp.hash()) != *exp_hash {
-                        return false;
-                    }
-                    curr_cp = query_cp;
-                }
-                None => {
-                    if exp_hash.is_some() {
-                        return false;
-                    }
-                }
-            }
-        }
-        true
-    }
-
-    /// Get checkpoint at given `height` (if it exists).
-    ///
-    /// This is a shorthand for calling [`CheckPoint::get`] on the [`tip`].
-    ///
-    /// [`tip`]: LocalChain::tip
-    pub fn get(&self, height: u32) -> Option<CheckPoint> {
-        self.tip.get(height)
-    }
-
-    /// Iterate checkpoints over a height range.
-    ///
-    /// Note that we always iterate checkpoints in reverse height order (iteration starts at tip
-    /// height).
-    ///
-    /// This is a shorthand for calling [`CheckPoint::range`] on the [`tip`].
-    ///
-    /// [`tip`]: LocalChain::tip
-    pub fn range<R>(&self, range: R) -> impl Iterator<Item = CheckPoint>
-    where
-        R: RangeBounds<u32>,
-    {
-        self.tip.range(range)
-    }
-}
-
-/// An error which occurs when a [`LocalChain`] is constructed without a genesis checkpoint.
-#[derive(Clone, Debug, PartialEq)]
-pub struct MissingGenesisError;
-
-impl core::fmt::Display for MissingGenesisError {
-    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-        write!(
-            f,
-            "cannot construct `LocalChain` without a genesis checkpoint"
-        )
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for MissingGenesisError {}
-
-/// Represents a failure when trying to insert/remove a checkpoint to/from [`LocalChain`].
-#[derive(Clone, Debug, PartialEq)]
-pub struct AlterCheckPointError {
-    /// The checkpoint's height.
-    pub height: u32,
-    /// The original checkpoint's block hash which cannot be replaced/removed.
-    pub original_hash: BlockHash,
-    /// The attempted update to the `original_block` hash.
-    pub update_hash: Option<BlockHash>,
-}
-
-impl core::fmt::Display for AlterCheckPointError {
-    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-        match self.update_hash {
-            Some(update_hash) => write!(
-                f,
-                "failed to insert block at height {}: original={} update={}",
-                self.height, self.original_hash, update_hash
-            ),
-            None => write!(
-                f,
-                "failed to remove block at height {}: original={}",
-                self.height, self.original_hash
-            ),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for AlterCheckPointError {}
-
-/// Occurs when an update does not have a common checkpoint with the original chain.
-#[derive(Clone, Debug, PartialEq)]
-pub struct CannotConnectError {
-    /// The suggested checkpoint to include to connect the two chains.
-    pub try_include_height: u32,
-}
-
-impl core::fmt::Display for CannotConnectError {
-    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-        write!(
-            f,
-            "introduced chain cannot connect with the original chain, try include height {}",
-            self.try_include_height,
-        )
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for CannotConnectError {}
-
-/// The error type for [`LocalChain::apply_header_connected_to`].
-#[derive(Debug, Clone, PartialEq)]
-pub enum ApplyHeaderError {
-    /// Occurs when `connected_to` block conflicts with either the current block or previous block.
-    InconsistentBlocks,
-    /// Occurs when the update cannot connect with the original chain.
-    CannotConnect(CannotConnectError),
-}
-
-impl core::fmt::Display for ApplyHeaderError {
-    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-        match self {
-            ApplyHeaderError::InconsistentBlocks => write!(
-                f,
-                "the `connected_to` block conflicts with either the current or previous block"
-            ),
-            ApplyHeaderError::CannotConnect(err) => core::fmt::Display::fmt(err, f),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for ApplyHeaderError {}
-
-fn merge_chains(
-    original_tip: CheckPoint,
-    update_tip: CheckPoint,
-    introduce_older_blocks: bool,
-) -> Result<ChangeSet, CannotConnectError> {
-    let mut changeset = ChangeSet::default();
-    let mut orig = original_tip.into_iter();
-    let mut update = update_tip.into_iter();
-    let mut curr_orig = None;
-    let mut curr_update = None;
-    let mut prev_orig: Option<CheckPoint> = None;
-    let mut prev_update: Option<CheckPoint> = None;
-    let mut point_of_agreement_found = false;
-    let mut prev_orig_was_invalidated = false;
-    let mut potentially_invalidated_heights = vec![];
-
-    // To find the difference between the new chain and the original we iterate over both of them
-    // from the tip backwards in tandem. We always dealing with the highest one from either chain
-    // first and move to the next highest. The crucial logic is applied when they have blocks at the
-    // same height.
-    loop {
-        if curr_orig.is_none() {
-            curr_orig = orig.next();
-        }
-        if curr_update.is_none() {
-            curr_update = update.next();
-        }
-
-        match (curr_orig.as_ref(), curr_update.as_ref()) {
-            // Update block that doesn't exist in the original chain
-            (o, Some(u)) if Some(u.height()) > o.map(|o| o.height()) => {
-                changeset.insert(u.height(), Some(u.hash()));
-                prev_update = curr_update.take();
-            }
-            // Original block that isn't in the update
-            (Some(o), u) if Some(o.height()) > u.map(|u| u.height()) => {
-                // this block might be gone if an earlier block gets invalidated
-                potentially_invalidated_heights.push(o.height());
-                prev_orig_was_invalidated = false;
-                prev_orig = curr_orig.take();
-
-                // OPTIMIZATION: we have run out of update blocks so we don't need to continue
-                // iterating because there's no possibility of adding anything to changeset.
-                if u.is_none() {
-                    break;
-                }
-            }
-            (Some(o), Some(u)) => {
-                if o.hash() == u.hash() {
-                    // We have found our point of agreement 🎉 -- we require that the previous (i.e.
-                    // higher because we are iterating backwards) block in the original chain was
-                    // invalidated (if it exists). This ensures that there is an unambiguous point of
-                    // connection to the original chain from the update chain (i.e. we know the
-                    // precisely which original blocks are invalid).
-                    if !prev_orig_was_invalidated && !point_of_agreement_found {
-                        if let (Some(prev_orig), Some(_prev_update)) = (&prev_orig, &prev_update) {
-                            return Err(CannotConnectError {
-                                try_include_height: prev_orig.height(),
-                            });
-                        }
-                    }
-                    point_of_agreement_found = true;
-                    prev_orig_was_invalidated = false;
-                    // OPTIMIZATION 1 -- If we know that older blocks cannot be introduced without
-                    // invalidation, we can break after finding the point of agreement.
-                    // OPTIMIZATION 2 -- if we have the same underlying pointer at this point, we
-                    // can guarantee that no older blocks are introduced.
-                    if !introduce_older_blocks || Arc::as_ptr(&o.0) == Arc::as_ptr(&u.0) {
-                        return Ok(changeset);
-                    }
-                } else {
-                    // We have an invalidation height so we set the height to the updated hash and
-                    // also purge all the original chain block hashes above this block.
-                    changeset.insert(u.height(), Some(u.hash()));
-                    for invalidated_height in potentially_invalidated_heights.drain(..) {
-                        changeset.insert(invalidated_height, None);
-                    }
-                    prev_orig_was_invalidated = true;
-                }
-                prev_update = curr_update.take();
-                prev_orig = curr_orig.take();
-            }
-            (None, None) => {
-                break;
-            }
-            _ => {
-                unreachable!("compiler cannot tell that everything has been covered")
-            }
-        }
-    }
-
-    // When we don't have a point of agreement you can imagine it is implicitly the
-    // genesis block so we need to do the final connectivity check which in this case
-    // just means making sure the entire original chain was invalidated.
-    if !prev_orig_was_invalidated && !point_of_agreement_found {
-        if let Some(prev_orig) = prev_orig {
-            return Err(CannotConnectError {
-                try_include_height: prev_orig.height(),
-            });
-        }
-    }
-
-    Ok(changeset)
-}
--- a/crates/chain/src/persist.rs
+++ b/crates/chain/src/persist.rs
@@ -1,109 +0,0 @@
-use core::convert::Infallible;
-
-use crate::Append;
-
-/// `Persist` wraps a [`PersistBackend`] (`B`) to create a convenient staging area for changes (`C`)
-/// before they are persisted.
-///
-/// Not all changes to the in-memory representation needs to be written to disk right away, so
-/// [`Persist::stage`] can be used to *stage* changes first and then [`Persist::commit`] can be used
-/// to write changes to disk.
-#[derive(Debug)]
-pub struct Persist<B, C> {
-    backend: B,
-    stage: C,
-}
-
-impl<B, C> Persist<B, C>
-where
-    B: PersistBackend<C>,
-    C: Default + Append,
-{
-    /// Create a new [`Persist`] from [`PersistBackend`].
-    pub fn new(backend: B) -> Self {
-        Self {
-            backend,
-            stage: Default::default(),
-        }
-    }
-
-    /// Stage a `changeset` to be committed later with [`commit`].
-    ///
-    /// [`commit`]: Self::commit
-    pub fn stage(&mut self, changeset: C) {
-        self.stage.append(changeset)
-    }
-
-    /// Get the changes that have not been committed yet.
-    pub fn staged(&self) -> &C {
-        &self.stage
-    }
-
-    /// Commit the staged changes to the underlying persistence backend.
-    ///
-    /// Changes that are committed (if any) are returned.
-    ///
-    /// # Error
-    ///
-    /// Returns a backend-defined error if this fails.
-    pub fn commit(&mut self) -> Result<Option<C>, B::WriteError> {
-        if self.stage.is_empty() {
-            return Ok(None);
-        }
-        self.backend
-            .write_changes(&self.stage)
-            // if written successfully, take and return `self.stage`
-            .map(|_| Some(core::mem::take(&mut self.stage)))
-    }
-
-    /// Stages a new changeset and commits it (along with any other previously staged changes) to
-    /// the persistence backend
-    ///
-    /// Convenience method for calling [`stage`] and then [`commit`].
-    ///
-    /// [`stage`]: Self::stage
-    /// [`commit`]: Self::commit
-    pub fn stage_and_commit(&mut self, changeset: C) -> Result<Option<C>, B::WriteError> {
-        self.stage(changeset);
-        self.commit()
-    }
-}
-
-/// A persistence backend for [`Persist`].
-///
-/// `C` represents the changeset; a datatype that records changes made to in-memory data structures
-/// that are to be persisted, or retrieved from persistence.
-pub trait PersistBackend<C> {
-    /// The error the backend returns when it fails to write.
-    type WriteError: core::fmt::Debug;
-
-    /// The error the backend returns when it fails to load changesets `C`.
-    type LoadError: core::fmt::Debug;
-
-    /// Writes a changeset to the persistence backend.
-    ///
-    /// It is up to the backend what it does with this. It could store every changeset in a list or
-    /// it inserts the actual changes into a more structured database. All it needs to guarantee is
-    /// that [`load_from_persistence`] restores a keychain tracker to what it should be if all
-    /// changesets had been applied sequentially.
-    ///
-    /// [`load_from_persistence`]: Self::load_from_persistence
-    fn write_changes(&mut self, changeset: &C) -> Result<(), Self::WriteError>;
-
-    /// Return the aggregate changeset `C` from persistence.
-    fn load_from_persistence(&mut self) -> Result<Option<C>, Self::LoadError>;
-}
-
-impl<C> PersistBackend<C> for () {
-    type WriteError = Infallible;
-
-    type LoadError = Infallible;
-
-    fn write_changes(&mut self, _changeset: &C) -> Result<(), Self::WriteError> {
-        Ok(())
-    }
-
-    fn load_from_persistence(&mut self) -> Result<Option<C>, Self::LoadError> {
-        Ok(None)
-    }
-}
--- a/crates/chain/src/sparse_chain.rs
+++ b/crates/chain/src/sparse_chain.rs
--- a/crates/chain/src/spk_iter.rs
+++ b/crates/chain/src/spk_iter.rs
@@ -1,274 +0,0 @@
-use crate::{
-    bitcoin::{secp256k1::Secp256k1, ScriptBuf},
-    miniscript::{Descriptor, DescriptorPublicKey},
-};
-use core::{borrow::Borrow, ops::Bound, ops::RangeBounds};
-
-/// Maximum [BIP32](https://bips.xyz/32) derivation index.
-pub const BIP32_MAX_INDEX: u32 = (1 << 31) - 1;
-
-/// An iterator for derived script pubkeys.
-///
-/// [`SpkIterator`] is an implementation of the [`Iterator`] trait which possesses its own `next()`
-/// and `nth()` functions, both of which circumvent the unnecessary intermediate derivations required
-/// when using their default implementations.
-///
-/// ## Examples
-///
-/// ```
-/// use bdk_chain::SpkIterator;
-/// # use miniscript::{Descriptor, DescriptorPublicKey};
-/// # use bitcoin::{secp256k1::Secp256k1};
-/// # use std::str::FromStr;
-/// # let secp = bitcoin::secp256k1::Secp256k1::signing_only();
-/// # let (descriptor, _) = Descriptor::<DescriptorPublicKey>::parse_descriptor(&secp, "wpkh([73c5da0a/86'/0'/0']xprv9xgqHN7yz9MwCkxsBPN5qetuNdQSUttZNKw1dcYTV4mkaAFiBVGQziHs3NRSWMkCzvgjEe3n9xV8oYywvM8at9yRqyaZVz6TYYhX98VjsUk/1/0)").unwrap();
-/// # let external_spk_0 = descriptor.at_derivation_index(0).unwrap().script_pubkey();
-/// # let external_spk_3 = descriptor.at_derivation_index(3).unwrap().script_pubkey();
-/// # let external_spk_4 = descriptor.at_derivation_index(4).unwrap().script_pubkey();
-///
-/// // Creates a new script pubkey iterator starting at 0 from a descriptor.
-/// let mut spk_iter = SpkIterator::new(&descriptor);
-/// assert_eq!(spk_iter.next(), Some((0, external_spk_0)));
-/// assert_eq!(spk_iter.next(), None);
-/// ```
-#[derive(Clone)]
-pub struct SpkIterator<D> {
-    next_index: u32,
-    end: u32,
-    descriptor: D,
-    secp: Secp256k1<bitcoin::secp256k1::VerifyOnly>,
-}
-
-impl<D> SpkIterator<D>
-where
-    D: Borrow<Descriptor<DescriptorPublicKey>>,
-{
-    /// Create a new script pubkey iterator from `descriptor`.
-    ///
-    /// This iterates from derivation index 0 and stops at index 0x7FFFFFFF (as specified in
-    /// BIP-32). Non-wildcard descriptors will only return one script pubkey at derivation index 0.
-    ///
-    /// Use [`new_with_range`](SpkIterator::new_with_range) to create an iterator with a specified
-    /// derivation index range.
-    pub fn new(descriptor: D) -> Self {
-        SpkIterator::new_with_range(descriptor, 0..=BIP32_MAX_INDEX)
-    }
-
-    /// Create a new script pubkey iterator from `descriptor` and a given `range`.
-    ///
-    /// Non-wildcard descriptors will only emit a single script pubkey (at derivation index 0).
-    /// Wildcard descriptors have an end-bound of 0x7FFFFFFF (inclusive).
-    ///
-    /// Refer to [`new`](SpkIterator::new) for more.
-    pub fn new_with_range<R>(descriptor: D, range: R) -> Self
-    where
-        R: RangeBounds<u32>,
-    {
-        let start = match range.start_bound() {
-            Bound::Included(start) => *start,
-            Bound::Excluded(start) => *start + 1,
-            Bound::Unbounded => u32::MIN,
-        };
-
-        let mut end = match range.end_bound() {
-            Bound::Included(end) => *end + 1,
-            Bound::Excluded(end) => *end,
-            Bound::Unbounded => u32::MAX,
-        };
-
-        // Because `end` is exclusive, we want the maximum value to be BIP32_MAX_INDEX + 1.
-        end = end.min(BIP32_MAX_INDEX + 1);
-
-        Self {
-            next_index: start,
-            end,
-            descriptor,
-            secp: Secp256k1::verification_only(),
-        }
-    }
-
-    /// Get a reference to the internal descriptor.
-    pub fn descriptor(&self) -> &D {
-        &self.descriptor
-    }
-}
-
-impl<D> Iterator for SpkIterator<D>
-where
-    D: Borrow<Descriptor<DescriptorPublicKey>>,
-{
-    type Item = (u32, ScriptBuf);
-
-    fn next(&mut self) -> Option<Self::Item> {
-        // For non-wildcard descriptors, we expect the first element to be Some((0, spk)), then None after.
-        // For wildcard descriptors, we expect it to keep iterating until exhausted.
-        if self.next_index >= self.end {
-            return None;
-        }
-
-        // If the descriptor is non-wildcard, only index 0 will return an spk.
-        if !self.descriptor.borrow().has_wildcard() && self.next_index != 0 {
-            return None;
-        }
-
-        let script = self
-            .descriptor
-            .borrow()
-            .derived_descriptor(&self.secp, self.next_index)
-            .expect("the descriptor cannot need hardened derivation")
-            .script_pubkey();
-        let output = (self.next_index, script);
-
-        self.next_index += 1;
-
-        Some(output)
-    }
-
-    fn nth(&mut self, n: usize) -> Option<Self::Item> {
-        self.next_index = self
-            .next_index
-            .saturating_add(u32::try_from(n).unwrap_or(u32::MAX));
-        self.next()
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use crate::{
-        bitcoin::secp256k1::Secp256k1,
-        keychain::KeychainTxOutIndex,
-        miniscript::{Descriptor, DescriptorPublicKey},
-        spk_iter::{SpkIterator, BIP32_MAX_INDEX},
-    };
-
-    #[derive(Clone, Debug, PartialEq, Eq, Ord, PartialOrd)]
-    enum TestKeychain {
-        External,
-        Internal,
-    }
-
-    fn init_txout_index() -> (
-        KeychainTxOutIndex<TestKeychain>,
-        Descriptor<DescriptorPublicKey>,
-        Descriptor<DescriptorPublicKey>,
-    ) {
-        let mut txout_index = KeychainTxOutIndex::<TestKeychain>::new(0);
-
-        let secp = Secp256k1::signing_only();
-        let (external_descriptor,_) = Descriptor::<DescriptorPublicKey>::parse_descriptor(&secp, "tr([73c5da0a/86'/0'/0']xprv9xgqHN7yz9MwCkxsBPN5qetuNdQSUttZNKw1dcYTV4mkaAFiBVGQziHs3NRSWMkCzvgjEe3n9xV8oYywvM8at9yRqyaZVz6TYYhX98VjsUk/0/*)").unwrap();
-        let (internal_descriptor,_) = Descriptor::<DescriptorPublicKey>::parse_descriptor(&secp, "tr([73c5da0a/86'/0'/0']xprv9xgqHN7yz9MwCkxsBPN5qetuNdQSUttZNKw1dcYTV4mkaAFiBVGQziHs3NRSWMkCzvgjEe3n9xV8oYywvM8at9yRqyaZVz6TYYhX98VjsUk/1/*)").unwrap();
-
-        txout_index.add_keychain(TestKeychain::External, external_descriptor.clone());
-        txout_index.add_keychain(TestKeychain::Internal, internal_descriptor.clone());
-
-        (txout_index, external_descriptor, internal_descriptor)
-    }
-
-    #[test]
-    #[allow(clippy::iter_nth_zero)]
-    #[rustfmt::skip]
-    fn test_spkiterator_wildcard() {
-        let (_, external_desc, _) = init_txout_index();
-        let external_spk_0 = external_desc.at_derivation_index(0).unwrap().script_pubkey();
-        let external_spk_16 = external_desc.at_derivation_index(16).unwrap().script_pubkey();
-        let external_spk_20 = external_desc.at_derivation_index(20).unwrap().script_pubkey();
-        let external_spk_21 = external_desc.at_derivation_index(21).unwrap().script_pubkey();
-        let external_spk_max = external_desc.at_derivation_index(BIP32_MAX_INDEX).unwrap().script_pubkey();
-
-        let mut external_spk = SpkIterator::new(&external_desc);
-        let max_index = BIP32_MAX_INDEX - 22;
-
-        assert_eq!(external_spk.next(), Some((0, external_spk_0)));
-        assert_eq!(external_spk.nth(15), Some((16, external_spk_16)));
-        assert_eq!(external_spk.nth(3), Some((20, external_spk_20.clone())));
-        assert_eq!(external_spk.next(), Some((21, external_spk_21)));
-        assert_eq!(
-            external_spk.nth(max_index as usize),
-            Some((BIP32_MAX_INDEX, external_spk_max))
-        );
-        assert_eq!(external_spk.nth(0), None);
-
-        let mut external_spk = SpkIterator::new_with_range(&external_desc, 0..21);
-        assert_eq!(external_spk.nth(20), Some((20, external_spk_20)));
-        assert_eq!(external_spk.next(), None);
-
-        let mut external_spk = SpkIterator::new_with_range(&external_desc, 0..21);
-        assert_eq!(external_spk.nth(21), None);
-    }
-
-    #[test]
-    #[allow(clippy::iter_nth_zero)]
-    fn test_spkiterator_non_wildcard() {
-        let secp = bitcoin::secp256k1::Secp256k1::signing_only();
-        let (no_wildcard_descriptor, _) = Descriptor::<DescriptorPublicKey>::parse_descriptor(&secp, "wpkh([73c5da0a/86'/0'/0']xprv9xgqHN7yz9MwCkxsBPN5qetuNdQSUttZNKw1dcYTV4mkaAFiBVGQziHs3NRSWMkCzvgjEe3n9xV8oYywvM8at9yRqyaZVz6TYYhX98VjsUk/1/0)").unwrap();
-        let external_spk_0 = no_wildcard_descriptor
-            .at_derivation_index(0)
-            .unwrap()
-            .script_pubkey();
-
-        let mut external_spk = SpkIterator::new(&no_wildcard_descriptor);
-
-        assert_eq!(external_spk.next(), Some((0, external_spk_0.clone())));
-        assert_eq!(external_spk.next(), None);
-
-        let mut external_spk = SpkIterator::new(&no_wildcard_descriptor);
-
-        assert_eq!(external_spk.nth(0), Some((0, external_spk_0.clone())));
-        assert_eq!(external_spk.nth(0), None);
-
-        let mut external_spk = SpkIterator::new_with_range(&no_wildcard_descriptor, 0..0);
-
-        assert_eq!(external_spk.next(), None);
-
-        let mut external_spk = SpkIterator::new_with_range(&no_wildcard_descriptor, 0..1);
-
-        assert_eq!(external_spk.nth(0), Some((0, external_spk_0.clone())));
-        assert_eq!(external_spk.next(), None);
-
-        // We test that using new_with_range with range_len > 1 gives back an iterator with
-        // range_len = 1
-        let mut external_spk = SpkIterator::new_with_range(&no_wildcard_descriptor, 0..10);
-
-        assert_eq!(external_spk.nth(0), Some((0, external_spk_0)));
-        assert_eq!(external_spk.nth(0), None);
-
-        // non index-0 should NOT return an spk
-        assert_eq!(
-            SpkIterator::new_with_range(&no_wildcard_descriptor, 1..1).next(),
-            None
-        );
-        assert_eq!(
-            SpkIterator::new_with_range(&no_wildcard_descriptor, 1..=1).next(),
-            None
-        );
-        assert_eq!(
-            SpkIterator::new_with_range(&no_wildcard_descriptor, 1..2).next(),
-            None
-        );
-        assert_eq!(
-            SpkIterator::new_with_range(&no_wildcard_descriptor, 1..=2).next(),
-            None
-        );
-        assert_eq!(
-            SpkIterator::new_with_range(&no_wildcard_descriptor, 10..11).next(),
-            None
-        );
-        assert_eq!(
-            SpkIterator::new_with_range(&no_wildcard_descriptor, 10..=10).next(),
-            None
-        );
-    }
-
-    // The following dummy traits were created to test if SpkIterator is working properly.
-    trait TestSendStatic: Send + 'static {
-        fn test(&self) -> u32 {
-            20
-        }
-    }
-
-    impl TestSendStatic for SpkIterator<Descriptor<DescriptorPublicKey>> {
-        fn test(&self) -> u32 {
-            20
-        }
-    }
-}
--- a/crates/chain/src/spk_txout_index.rs
+++ b/crates/chain/src/spk_txout_index.rs
@@ -2,16 +2,15 @@ use core::ops::RangeBounds;

 use crate::{
    collections::{hash_map::Entry, BTreeMap, BTreeSet, HashMap},
-    indexed_tx_graph::Indexer,
+    ForEachTxOut,
 };
-use bitcoin::{OutPoint, Script, ScriptBuf, Transaction, TxOut, Txid};
+use bitcoin::{self, OutPoint, Script, Transaction, TxOut, Txid};

 /// An index storing [`TxOut`]s that have a script pubkey that matches those in a list.
 ///
 /// The basic idea is that you insert script pubkeys you care about into the index with
-/// [`insert_spk`] and then when you call [`Indexer::index_tx`] or [`Indexer::index_txout`], the
-/// index will look at any txouts you pass in and store and index any txouts matching one of its
-/// script pubkeys.
+/// [`insert_spk`] and then when you call [`scan`], the index will look at any txouts you pass in and
+/// store and index any txouts matching one of its script pubkeys.
 ///
 /// Each script pubkey is associated with an application-defined index script index `I`, which must be
 /// [`Ord`]. Usually, this is used to associate the derivation index of the script pubkey or even a
@@ -20,18 +19,19 @@ use bitcoin::{OutPoint, Script, ScriptBuf, Transaction, TxOut, Txid};
 /// Note there is no harm in scanning transactions that disappear from the blockchain or were never
 /// in there in the first place. `SpkTxOutIndex` is intentionally *monotone* -- you cannot delete or
 /// modify txouts that have been indexed. To find out which txouts from the index are actually in the
-/// chain or unspent, you must use other sources of information like a [`TxGraph`].
+/// chain or unspent, you must use other sources of information like a [`SparseChain`].
 ///
 /// [`TxOut`]: bitcoin::TxOut
 /// [`insert_spk`]: Self::insert_spk
 /// [`Ord`]: core::cmp::Ord
-/// [`TxGraph`]: crate::tx_graph::TxGraph
+/// [`scan`]: Self::scan
+/// [`SparseChain`]: crate::sparse_chain::SparseChain
 #[derive(Clone, Debug)]
 pub struct SpkTxOutIndex<I> {
    /// script pubkeys ordered by index
-    spks: BTreeMap<I, ScriptBuf>,
+    spks: BTreeMap<I, Script>,
    /// A reverse lookup from spk to spk index
-    spk_indices: HashMap<ScriptBuf, I>,
+    spk_indices: HashMap<Script, I>,
    /// The set of unused indexes.
    unused: BTreeSet<I>,
    /// Lookup index and txout by outpoint.
@@ -52,47 +52,41 @@ impl<I> Default for SpkTxOutIndex<I> {
    }
 }

-impl<I: Clone + Ord> Indexer for SpkTxOutIndex<I> {
-    type ChangeSet = ();
-
-    fn index_txout(&mut self, outpoint: OutPoint, txout: &TxOut) -> Self::ChangeSet {
-        self.scan_txout(outpoint, txout);
-        Default::default()
-    }
-
-    fn index_tx(&mut self, tx: &Transaction) -> Self::ChangeSet {
-        self.scan(tx);
-        Default::default()
-    }
-
-    fn initial_changeset(&self) -> Self::ChangeSet {}
-
-    fn apply_changeset(&mut self, _changeset: Self::ChangeSet) {
-        // This applies nothing.
-    }
-
-    fn is_tx_relevant(&self, tx: &Transaction) -> bool {
-        self.is_relevant(tx)
-    }
+/// This macro is used instead of a member function of `SpkTxOutIndex`, which would result in a
+/// compiler error[E0521]: "borrowed data escapes out of closure" when we attempt to take a
+/// reference out of the `ForEachTxOut` closure during scanning.
+macro_rules! scan_txout {
+    ($self:ident, $op:expr, $txout:expr) => {{
+        let spk_i = $self.spk_indices.get(&$txout.script_pubkey);
+        if let Some(spk_i) = spk_i {
+            $self.txouts.insert($op, (spk_i.clone(), $txout.clone()));
+            $self.spk_txouts.insert((spk_i.clone(), $op));
+            $self.unused.remove(&spk_i);
+        }
+        spk_i
+    }};
 }

 impl<I: Clone + Ord> SpkTxOutIndex<I> {
-    /// Scans a transaction's outputs for matching script pubkeys.
+    /// Scans an object containing many txouts.
    ///
    /// Typically, this is used in two situations:
    ///
    /// 1. After loading transaction data from the disk, you may scan over all the txouts to restore all
    /// your txouts.
    /// 2. When getting new data from the chain, you usually scan it before incorporating it into your chain state.
-    pub fn scan(&mut self, tx: &Transaction) -> BTreeSet<I> {
+    ///
+    /// See [`ForEachTxout`] for the types that support this.
+    ///
+    /// [`ForEachTxout`]: crate::ForEachTxOut
+    pub fn scan(&mut self, txouts: &impl ForEachTxOut) -> BTreeSet<I> {
        let mut scanned_indices = BTreeSet::new();
-        let txid = tx.txid();
-        for (i, txout) in tx.output.iter().enumerate() {
-            let op = OutPoint::new(txid, i as u32);
-            if let Some(spk_i) = self.scan_txout(op, txout) {
+
+        txouts.for_each_txout(|(op, txout)| {
+            if let Some(spk_i) = scan_txout!(self, op, txout) {
                scanned_indices.insert(spk_i.clone());
            }
-        }
+        });

        scanned_indices
    }
@@ -100,18 +94,7 @@ impl<I: Clone + Ord> SpkTxOutIndex<I> {
    /// Scan a single `TxOut` for a matching script pubkey and returns the index that matches the
    /// script pubkey (if any).
    pub fn scan_txout(&mut self, op: OutPoint, txout: &TxOut) -> Option<&I> {
-        let spk_i = self.spk_indices.get(&txout.script_pubkey);
-        if let Some(spk_i) = spk_i {
-            self.txouts.insert(op, (spk_i.clone(), txout.clone()));
-            self.spk_txouts.insert((spk_i.clone(), op));
-            self.unused.remove(spk_i);
-        }
-        spk_i
-    }
-
-    /// Get a reference to the set of indexed outpoints.
-    pub fn outpoints(&self) -> &BTreeSet<(I, OutPoint)> {
-        &self.spk_txouts
+        scan_txout!(self, op, txout)
    }

    /// Iterate over all known txouts that spend to tracked script pubkeys.
@@ -141,11 +124,11 @@ impl<I: Clone + Ord> SpkTxOutIndex<I> {
        use bitcoin::hashes::Hash;
        use core::ops::Bound::*;
        let min_op = OutPoint {
-            txid: Txid::all_zeros(),
+            txid: Txid::from_inner([0x00; 32]),
            vout: u32::MIN,
        };
        let max_op = OutPoint {
-            txid: Txid::from_byte_array([0xff; Txid::LEN]),
+            txid: Txid::from_inner([0xff; 32]),
            vout: u32::MAX,
        };

@@ -168,25 +151,27 @@ impl<I: Clone + Ord> SpkTxOutIndex<I> {
    ///
    /// Returns `None` if the `TxOut` hasn't been scanned or if nothing matching was found there.
    pub fn txout(&self, outpoint: OutPoint) -> Option<(&I, &TxOut)> {
-        self.txouts.get(&outpoint).map(|v| (&v.0, &v.1))
+        self.txouts
+            .get(&outpoint)
+            .map(|(spk_i, txout)| (spk_i, txout))
    }

    /// Returns the script that has been inserted at the `index`.
    ///
    /// If that index hasn't been inserted yet, it will return `None`.
    pub fn spk_at_index(&self, index: &I) -> Option<&Script> {
-        self.spks.get(index).map(|s| s.as_script())
+        self.spks.get(index)
    }

    /// The script pubkeys that are being tracked by the index.
-    pub fn all_spks(&self) -> &BTreeMap<I, ScriptBuf> {
+    pub fn all_spks(&self) -> &BTreeMap<I, Script> {
        &self.spks
    }

    /// Adds a script pubkey to scan for. Returns `false` and does nothing if spk already exists in the map
    ///
    /// the index will look for outputs spending to this spk whenever it scans new data.
-    pub fn insert_spk(&mut self, index: I, spk: ScriptBuf) -> bool {
+    pub fn insert_spk(&mut self, index: I, spk: Script) -> bool {
        match self.spk_indices.entry(spk.clone()) {
            Entry::Vacant(value) => {
                value.insert(index.clone());
@@ -215,7 +200,7 @@ impl<I: Clone + Ord> SpkTxOutIndex<I> {
    /// let unused_change_spks =
    ///     txout_index.unused_spks((change_index, u32::MIN)..(change_index, u32::MAX));
    /// ```
-    pub fn unused_spks<R>(&self, range: R) -> impl DoubleEndedIterator<Item = (&I, &Script)> + Clone
+    pub fn unused_spks<R>(&self, range: R) -> impl DoubleEndedIterator<Item = (&I, &Script)>
    where
        R: RangeBounds<I>,
    {
@@ -273,20 +258,20 @@ impl<I: Clone + Ord> SpkTxOutIndex<I> {
    /// Computes total input value going from script pubkeys in the index (sent) and the total output
    /// value going to script pubkeys in the index (received) in `tx`. For the `sent` to be computed
    /// correctly, the output being spent must have already been scanned by the index. Calculating
-    /// received just uses the [`Transaction`] outputs directly, so it will be correct even if it has
-    /// not been scanned.
+    /// received just uses the transaction outputs directly, so it will be correct even if it has not
+    /// been scanned.
    pub fn sent_and_received(&self, tx: &Transaction) -> (u64, u64) {
        let mut sent = 0;
        let mut received = 0;

        for txin in &tx.input {
            if let Some((_, txout)) = self.txout(txin.previous_output) {
-                sent += txout.value.to_sat();
+                sent += txout.value;
            }
        }
        for txout in &tx.output {
            if self.index_of_spk(&txout.script_pubkey).is_some() {
-                received += txout.value.to_sat();
+                received += txout.value;
            }
        }

--- a/crates/chain/src/tx_data_traits.rs
+++ b/crates/chain/src/tx_data_traits.rs
@@ -1,185 +1,33 @@
-use crate::collections::BTreeMap;
-use crate::collections::BTreeSet;
-use crate::BlockId;
-use alloc::vec::Vec;
+use bitcoin::{Block, OutPoint, Transaction, TxOut};

-/// Trait that "anchors" blockchain data to a specific block of height and hash.
+/// Trait to do something with every txout contained in a structure.
 ///
-/// If transaction A is anchored in block B, and block B is in the best chain, we can
-/// assume that transaction A is also confirmed in the best chain. This does not necessarily mean
-/// that transaction A is confirmed in block B. It could also mean transaction A is confirmed in a
-/// parent block of B.
-///
-/// Every [`Anchor`] implementation must contain a [`BlockId`] parameter, and must implement
-/// [`Ord`]. When implementing [`Ord`], the anchors' [`BlockId`]s should take precedence
-/// over other elements inside the [`Anchor`]s for comparison purposes, i.e., you should first
-/// compare the anchors' [`BlockId`]s and then care about the rest.
-///
-/// The example shows different types of anchors:
-/// ```
-/// # use bdk_chain::local_chain::LocalChain;
-/// # use bdk_chain::tx_graph::TxGraph;
-/// # use bdk_chain::BlockId;
-/// # use bdk_chain::ConfirmationHeightAnchor;
-/// # use bdk_chain::ConfirmationTimeHeightAnchor;
-/// # use bdk_chain::example_utils::*;
-/// # use bitcoin::hashes::Hash;
-/// // Initialize the local chain with two blocks.
-/// let chain = LocalChain::from_blocks(
-///     [
-///         (1, Hash::hash("first".as_bytes())),
-///         (2, Hash::hash("second".as_bytes())),
-///     ]
-///     .into_iter()
-///     .collect(),
-/// );
-///
-/// // Transaction to be inserted into `TxGraph`s with different anchor types.
-/// let tx = tx_from_hex(RAW_TX_1);
-///
-/// // Insert `tx` into a `TxGraph` that uses `BlockId` as the anchor type.
-/// // When a transaction is anchored with `BlockId`, the anchor block and the confirmation block of
-/// // the transaction is the same block.
-/// let mut graph_a = TxGraph::<BlockId>::default();
-/// let _ = graph_a.insert_tx(tx.clone());
-/// graph_a.insert_anchor(
-///     tx.txid(),
-///     BlockId {
-///         height: 1,
-///         hash: Hash::hash("first".as_bytes()),
-///     },
-/// );
-///
-/// // Insert `tx` into a `TxGraph` that uses `ConfirmationHeightAnchor` as the anchor type.
-/// // This anchor records the anchor block and the confirmation height of the transaction.
-/// // When a transaction is anchored with `ConfirmationHeightAnchor`, the anchor block and
-/// // confirmation block can be different. However, the confirmation block cannot be higher than
-/// // the anchor block and both blocks must be in the same chain for the anchor to be valid.
-/// let mut graph_b = TxGraph::<ConfirmationHeightAnchor>::default();
-/// let _ = graph_b.insert_tx(tx.clone());
-/// graph_b.insert_anchor(
-///     tx.txid(),
-///     ConfirmationHeightAnchor {
-///         anchor_block: BlockId {
-///             height: 2,
-///             hash: Hash::hash("second".as_bytes()),
-///         },
-///         confirmation_height: 1,
-///     },
-/// );
-///
-/// // Insert `tx` into a `TxGraph` that uses `ConfirmationTimeHeightAnchor` as the anchor type.
-/// // This anchor records the anchor block, the confirmation height and time of the transaction.
-/// // When a transaction is anchored with `ConfirmationTimeHeightAnchor`, the anchor block and
-/// // confirmation block can be different. However, the confirmation block cannot be higher than
-/// // the anchor block and both blocks must be in the same chain for the anchor to be valid.
-/// let mut graph_c = TxGraph::<ConfirmationTimeHeightAnchor>::default();
-/// let _ = graph_c.insert_tx(tx.clone());
-/// graph_c.insert_anchor(
-///     tx.txid(),
-///     ConfirmationTimeHeightAnchor {
-///         anchor_block: BlockId {
-///             height: 2,
-///             hash: Hash::hash("third".as_bytes()),
-///         },
-///         confirmation_height: 1,
-///         confirmation_time: 123,
-///     },
-/// );
-/// ```
-pub trait Anchor: core::fmt::Debug + Clone + Eq + PartialOrd + Ord + core::hash::Hash {
-    /// Returns the [`BlockId`] that the associated blockchain data is "anchored" in.
-    fn anchor_block(&self) -> BlockId;
-
-    /// Get the upper bound of the chain data's confirmation height.
-    ///
-    /// The default definition gives a pessimistic answer. This can be overridden by the `Anchor`
-    /// implementation for a more accurate value.
-    fn confirmation_height_upper_bound(&self) -> u32 {
-        self.anchor_block().height
-    }
+/// We would prefer to just work with things that can give us an `Iterator<Item=(OutPoint, &TxOut)>`
+/// here, but rust's type system makes it extremely hard to do this (without trait objects).
+pub trait ForEachTxOut {
+    /// The provided closure `f` will be called with each `outpoint/txout` pair.
+    fn for_each_txout(&self, f: impl FnMut((OutPoint, &TxOut)));
 }

-impl<'a, A: Anchor> Anchor for &'a A {
-    fn anchor_block(&self) -> BlockId {
-        <A as Anchor>::anchor_block(self)
-    }
-}
-
-/// An [`Anchor`] that can be constructed from a given block, block height and transaction position
-/// within the block.
-pub trait AnchorFromBlockPosition: Anchor {
-    /// Construct the anchor from a given `block`, block height and `tx_pos` within the block.
-    fn from_block_position(block: &bitcoin::Block, block_id: BlockId, tx_pos: usize) -> Self;
-}
-
-/// Trait that makes an object appendable.
-pub trait Append {
-    /// Append another object of the same type onto `self`.
-    fn append(&mut self, other: Self);
-
-    /// Returns whether the structure is considered empty.
-    fn is_empty(&self) -> bool;
-}
-
-impl<K: Ord, V> Append for BTreeMap<K, V> {
-    fn append(&mut self, other: Self) {
-        // We use `extend` instead of `BTreeMap::append` due to performance issues with `append`.
-        // Refer to https://github.com/rust-lang/rust/issues/34666#issuecomment-675658420
-        BTreeMap::extend(self, other)
-    }
-
-    fn is_empty(&self) -> bool {
-        BTreeMap::is_empty(self)
-    }
-}
-
-impl<T: Ord> Append for BTreeSet<T> {
-    fn append(&mut self, other: Self) {
-        // We use `extend` instead of `BTreeMap::append` due to performance issues with `append`.
-        // Refer to https://github.com/rust-lang/rust/issues/34666#issuecomment-675658420
-        BTreeSet::extend(self, other)
-    }
-
-    fn is_empty(&self) -> bool {
-        BTreeSet::is_empty(self)
-    }
-}
-
-impl<T> Append for Vec<T> {
-    fn append(&mut self, mut other: Self) {
-        Vec::append(self, &mut other)
-    }
-
-    fn is_empty(&self) -> bool {
-        Vec::is_empty(self)
-    }
-}
-
-macro_rules! impl_append_for_tuple {
-    ($($a:ident $b:tt)*) => {
-        impl<$($a),*> Append for ($($a,)*) where $($a: Append),* {
-
-            fn append(&mut self, _other: Self) {
-                $(Append::append(&mut self.$b, _other.$b) );*
-            }
-
-            fn is_empty(&self) -> bool {
-                $(Append::is_empty(&self.$b) && )* true
-            }
+impl ForEachTxOut for Block {
+    fn for_each_txout(&self, mut f: impl FnMut((OutPoint, &TxOut))) {
+        for tx in self.txdata.iter() {
+            tx.for_each_txout(&mut f)
        }
    }
 }

-impl_append_for_tuple!();
-impl_append_for_tuple!(T0 0);
-impl_append_for_tuple!(T0 0 T1 1);
-impl_append_for_tuple!(T0 0 T1 1 T2 2);
-impl_append_for_tuple!(T0 0 T1 1 T2 2 T3 3);
-impl_append_for_tuple!(T0 0 T1 1 T2 2 T3 3 T4 4);
-impl_append_for_tuple!(T0 0 T1 1 T2 2 T3 3 T4 4 T5 5);
-impl_append_for_tuple!(T0 0 T1 1 T2 2 T3 3 T4 4 T5 5 T6 6);
-impl_append_for_tuple!(T0 0 T1 1 T2 2 T3 3 T4 4 T5 5 T6 6 T7 7);
-impl_append_for_tuple!(T0 0 T1 1 T2 2 T3 3 T4 4 T5 5 T6 6 T7 7 T8 8);
-impl_append_for_tuple!(T0 0 T1 1 T2 2 T3 3 T4 4 T5 5 T6 6 T7 7 T8 8 T9 9);
-impl_append_for_tuple!(T0 0 T1 1 T2 2 T3 3 T4 4 T5 5 T6 6 T7 7 T8 8 T9 9 T10 10);
+impl ForEachTxOut for Transaction {
+    fn for_each_txout(&self, mut f: impl FnMut((OutPoint, &TxOut))) {
+        let txid = self.txid();
+        for (i, txout) in self.output.iter().enumerate() {
+            f((
+                OutPoint {
+                    txid,
+                    vout: i as u32,
+                },
+                txout,
+            ))
+        }
+    }
+}
--- a/crates/chain/src/tx_graph.rs
+++ b/crates/chain/src/tx_graph.rs
--- a/crates/chain/tests/common/mod.rs
+++ b/crates/chain/tests/common/mod.rs
@@ -1,17 +1,3 @@
-mod tx_template;
-#[allow(unused_imports)]
-pub use tx_template::*;
-
-#[allow(unused_macros)]
-macro_rules! block_id {
-    ($height:expr, $hash:literal) => {{
-        bdk_chain::BlockId {
-            height: $height,
-            hash: bitcoin::hashes::Hash::hash($hash.as_bytes()),
-        }
-    }};
-}
-
 #[allow(unused_macros)]
 macro_rules! h {
    ($index:literal) => {{
@@ -20,24 +6,20 @@ macro_rules! h {
 }

 #[allow(unused_macros)]
-macro_rules! local_chain {
-    [ $(($height:expr, $block_hash:expr)), * ] => {{
+macro_rules! chain {
+    ($([$($tt:tt)*]),*) => { chain!( checkpoints: [$([$($tt)*]),*] ) };
+    (checkpoints: $($tail:tt)*) => { chain!( index: TxHeight, checkpoints: $($tail)*) };
+    (index: $ind:ty, checkpoints: [ $([$height:expr, $block_hash:expr]),* ] $(,txids: [$(($txid:expr, $tx_height:expr)),*])?) => {{
        #[allow(unused_mut)]
-        bdk_chain::local_chain::LocalChain::from_blocks([$(($height, $block_hash).into()),*].into_iter().collect())
-            .expect("chain must have genesis block")
-    }};
-}
+        let mut chain = bdk_chain::sparse_chain::SparseChain::<$ind>::from_checkpoints([$(($height, $block_hash).into()),*]);

-#[allow(unused_macros)]
-macro_rules! chain_update {
-    [ $(($height:expr, $hash:expr)), * ] => {{
-        #[allow(unused_mut)]
-        bdk_chain::local_chain::Update {
-            tip: bdk_chain::local_chain::LocalChain::from_blocks([$(($height, $hash).into()),*].into_iter().collect())
-                .expect("chain must have genesis block")
-                .tip(),
-            introduce_older_blocks: true,
-        }
+        $(
+            $(
+                let _ = chain.insert_tx($txid, $tx_height).expect("should succeed");
+            )*
+        )?
+
+        chain
    }};
 }

@@ -70,8 +52,8 @@ macro_rules! changeset {
 #[allow(unused)]
 pub fn new_tx(lt: u32) -> bitcoin::Transaction {
    bitcoin::Transaction {
-        version: bitcoin::transaction::Version::non_standard(0x00),
-        lock_time: bitcoin::absolute::LockTime::from_consensus(lt),
+        version: 0x00,
+        lock_time: bitcoin::PackedLockTime(lt),
        input: vec![],
        output: vec![],
    }
--- a/crates/chain/tests/common/tx_template.rs
+++ b/crates/chain/tests/common/tx_template.rs
@@ -1,136 +0,0 @@
-use rand::distributions::{Alphanumeric, DistString};
-use std::collections::HashMap;
-
-use bdk_chain::{tx_graph::TxGraph, Anchor, SpkTxOutIndex};
-use bitcoin::{
-    locktime::absolute::LockTime, secp256k1::Secp256k1, transaction, Amount, OutPoint, ScriptBuf,
-    Sequence, Transaction, TxIn, TxOut, Txid, Witness,
-};
-use miniscript::Descriptor;
-
-/// Template for creating a transaction in `TxGraph`.
-///
-/// The incentive for transaction templates is to create a transaction history in a simple manner to
-/// avoid having to explicitly hash previous transactions to form previous outpoints of later
-/// transactions.
-#[derive(Clone, Copy, Default)]
-pub struct TxTemplate<'a, A> {
-    /// Uniquely identifies the transaction, before it can have a txid.
-    pub tx_name: &'a str,
-    pub inputs: &'a [TxInTemplate<'a>],
-    pub outputs: &'a [TxOutTemplate],
-    pub anchors: &'a [A],
-    pub last_seen: Option<u64>,
-}
-
-#[allow(dead_code)]
-pub enum TxInTemplate<'a> {
-    /// This will give a random txid and vout.
-    Bogus,
-
-    /// This is used for coinbase transactions because they do not have previous outputs.
-    Coinbase,
-
-    /// Contains the `tx_name` and `vout` that we are spending. The rule is that we must only spend
-    /// from tx of a previous `TxTemplate`.
-    PrevTx(&'a str, usize),
-}
-
-pub struct TxOutTemplate {
-    pub value: u64,
-    pub spk_index: Option<u32>, // some = get spk from SpkTxOutIndex, none = random spk
-}
-
-#[allow(unused)]
-impl TxOutTemplate {
-    pub fn new(value: u64, spk_index: Option<u32>) -> Self {
-        TxOutTemplate { value, spk_index }
-    }
-}
-
-#[allow(dead_code)]
-pub fn init_graph<'a, A: Anchor + Clone + 'a>(
-    tx_templates: impl IntoIterator<Item = &'a TxTemplate<'a, A>>,
-) -> (TxGraph<A>, SpkTxOutIndex<u32>, HashMap<&'a str, Txid>) {
-    let (descriptor, _) = Descriptor::parse_descriptor(&Secp256k1::signing_only(), "tr(tprv8ZgxMBicQKsPd3krDUsBAmtnRsK3rb8u5yi1zhQgMhF1tR8MW7xfE4rnrbbsrbPR52e7rKapu6ztw1jXveJSCGHEriUGZV7mCe88duLp5pj/86'/1'/0'/0/*)").unwrap();
-    let mut graph = TxGraph::<A>::default();
-    let mut spk_index = SpkTxOutIndex::default();
-    (0..10).for_each(|index| {
-        spk_index.insert_spk(
-            index,
-            descriptor
-                .at_derivation_index(index)
-                .unwrap()
-                .script_pubkey(),
-        );
-    });
-    let mut tx_ids = HashMap::<&'a str, Txid>::new();
-
-    for (bogus_txin_vout, tx_tmp) in tx_templates.into_iter().enumerate() {
-        let tx = Transaction {
-            version: transaction::Version::non_standard(0),
-            lock_time: LockTime::ZERO,
-            input: tx_tmp
-                .inputs
-                .iter()
-                .map(|input| match input {
-                    TxInTemplate::Bogus => TxIn {
-                        previous_output: OutPoint::new(
-                            bitcoin::hashes::Hash::hash(
-                                Alphanumeric
-                                    .sample_string(&mut rand::thread_rng(), 20)
-                                    .as_bytes(),
-                            ),
-                            bogus_txin_vout as u32,
-                        ),
-                        script_sig: ScriptBuf::new(),
-                        sequence: Sequence::default(),
-                        witness: Witness::new(),
-                    },
-                    TxInTemplate::Coinbase => TxIn {
-                        previous_output: OutPoint::null(),
-                        script_sig: ScriptBuf::new(),
-                        sequence: Sequence::MAX,
-                        witness: Witness::new(),
-                    },
-                    TxInTemplate::PrevTx(prev_name, prev_vout) => {
-                        let prev_txid = tx_ids.get(prev_name).expect(
-                            "txin template must spend from tx of template that comes before",
-                        );
-                        TxIn {
-                            previous_output: OutPoint::new(*prev_txid, *prev_vout as _),
-                            script_sig: ScriptBuf::new(),
-                            sequence: Sequence::default(),
-                            witness: Witness::new(),
-                        }
-                    }
-                })
-                .collect(),
-            output: tx_tmp
-                .outputs
-                .iter()
-                .map(|output| match &output.spk_index {
-                    None => TxOut {
-                        value: Amount::from_sat(output.value),
-                        script_pubkey: ScriptBuf::new(),
-                    },
-                    Some(index) => TxOut {
-                        value: Amount::from_sat(output.value),
-                        script_pubkey: spk_index.spk_at_index(index).unwrap().to_owned(),
-                    },
-                })
-                .collect(),
-        };
-
-        tx_ids.insert(tx_tmp.tx_name, tx.txid());
-        spk_index.scan(&tx);
-        let _ = graph.insert_tx(tx.clone());
-        for anchor in tx_tmp.anchors.iter() {
-            let _ = graph.insert_anchor(tx.txid(), anchor.clone());
-        }
-        if let Some(seen_at) = tx_tmp.last_seen {
-            let _ = graph.insert_seen_at(tx.txid(), seen_at);
-        }
-    }
-    (graph, spk_index, tx_ids)
-}
--- a/crates/chain/tests/test_chain_graph.rs
+++ b/crates/chain/tests/test_chain_graph.rs
@@ -0,0 +1,653 @@
+#[macro_use]
+mod common;
+
+use bdk_chain::{
+    chain_graph::*,
+    collections::HashSet,
+    sparse_chain,
+    tx_graph::{self, TxGraph},
+    BlockId, TxHeight,
+};
+use bitcoin::{OutPoint, PackedLockTime, Script, Sequence, Transaction, TxIn, TxOut, Witness};
+
+#[test]
+fn test_spent_by() {
+    let tx1 = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![],
+        output: vec![TxOut::default()],
+    };
+
+    let op = OutPoint {
+        txid: tx1.txid(),
+        vout: 0,
+    };
+
+    let tx2 = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![TxIn {
+            previous_output: op,
+            ..Default::default()
+        }],
+        output: vec![],
+    };
+    let tx3 = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(42),
+        input: vec![TxIn {
+            previous_output: op,
+            ..Default::default()
+        }],
+        output: vec![],
+    };
+
+    let mut cg1 = ChainGraph::default();
+    let _ = cg1
+        .insert_tx(tx1, TxHeight::Unconfirmed)
+        .expect("should insert");
+    let mut cg2 = cg1.clone();
+    let _ = cg1
+        .insert_tx(tx2.clone(), TxHeight::Unconfirmed)
+        .expect("should insert");
+    let _ = cg2
+        .insert_tx(tx3.clone(), TxHeight::Unconfirmed)
+        .expect("should insert");
+
+    assert_eq!(cg1.spent_by(op), Some((&TxHeight::Unconfirmed, tx2.txid())));
+    assert_eq!(cg2.spent_by(op), Some((&TxHeight::Unconfirmed, tx3.txid())));
+}
+
+#[test]
+fn update_evicts_conflicting_tx() {
+    let cp_a = BlockId {
+        height: 0,
+        hash: h!("A"),
+    };
+    let cp_b = BlockId {
+        height: 1,
+        hash: h!("B"),
+    };
+    let cp_b2 = BlockId {
+        height: 1,
+        hash: h!("B'"),
+    };
+
+    let tx_a = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![],
+        output: vec![TxOut::default()],
+    };
+
+    let tx_b = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![TxIn {
+            previous_output: OutPoint::new(tx_a.txid(), 0),
+            script_sig: Script::new(),
+            sequence: Sequence::default(),
+            witness: Witness::new(),
+        }],
+        output: vec![TxOut::default()],
+    };
+
+    let tx_b2 = Transaction {
+        version: 0x02,
+        lock_time: PackedLockTime(0),
+        input: vec![TxIn {
+            previous_output: OutPoint::new(tx_a.txid(), 0),
+            script_sig: Script::new(),
+            sequence: Sequence::default(),
+            witness: Witness::new(),
+        }],
+        output: vec![TxOut::default(), TxOut::default()],
+    };
+    {
+        let mut cg1 = {
+            let mut cg = ChainGraph::default();
+            let _ = cg.insert_checkpoint(cp_a).expect("should insert cp");
+            let _ = cg
+                .insert_tx(tx_a.clone(), TxHeight::Confirmed(0))
+                .expect("should insert tx");
+            let _ = cg
+                .insert_tx(tx_b.clone(), TxHeight::Unconfirmed)
+                .expect("should insert tx");
+            cg
+        };
+        let cg2 = {
+            let mut cg = ChainGraph::default();
+            let _ = cg
+                .insert_tx(tx_b2.clone(), TxHeight::Unconfirmed)
+                .expect("should insert tx");
+            cg
+        };
+
+        let changeset = ChangeSet::<TxHeight> {
+            chain: sparse_chain::ChangeSet {
+                checkpoints: Default::default(),
+                txids: [
+                    (tx_b.txid(), None),
+                    (tx_b2.txid(), Some(TxHeight::Unconfirmed)),
+                ]
+                .into(),
+            },
+            graph: tx_graph::Additions {
+                tx: [tx_b2.clone()].into(),
+                txout: [].into(),
+            },
+        };
+        assert_eq!(
+            cg1.determine_changeset(&cg2),
+            Ok(changeset.clone()),
+            "tx should be evicted from mempool"
+        );
+
+        cg1.apply_changeset(changeset);
+    }
+
+    {
+        let cg1 = {
+            let mut cg = ChainGraph::default();
+            let _ = cg.insert_checkpoint(cp_a).expect("should insert cp");
+            let _ = cg.insert_checkpoint(cp_b).expect("should insert cp");
+            let _ = cg
+                .insert_tx(tx_a.clone(), TxHeight::Confirmed(0))
+                .expect("should insert tx");
+            let _ = cg
+                .insert_tx(tx_b.clone(), TxHeight::Confirmed(1))
+                .expect("should insert tx");
+            cg
+        };
+        let cg2 = {
+            let mut cg = ChainGraph::default();
+            let _ = cg
+                .insert_tx(tx_b2.clone(), TxHeight::Unconfirmed)
+                .expect("should insert tx");
+            cg
+        };
+        assert_eq!(
+            cg1.determine_changeset(&cg2),
+            Err(UpdateError::UnresolvableConflict(UnresolvableConflict {
+                already_confirmed_tx: (TxHeight::Confirmed(1), tx_b.txid()),
+                update_tx: (TxHeight::Unconfirmed, tx_b2.txid()),
+            })),
+            "fail if tx is evicted from valid block"
+        );
+    }
+
+    {
+        // Given 2 blocks `{A, B}`, and an update that invalidates block B with
+        // `{A, B'}`, we expect txs that exist in `B` that conflicts with txs
+        // introduced in the update to be successfully evicted.
+        let mut cg1 = {
+            let mut cg = ChainGraph::default();
+            let _ = cg.insert_checkpoint(cp_a).expect("should insert cp");
+            let _ = cg.insert_checkpoint(cp_b).expect("should insert cp");
+            let _ = cg
+                .insert_tx(tx_a, TxHeight::Confirmed(0))
+                .expect("should insert tx");
+            let _ = cg
+                .insert_tx(tx_b.clone(), TxHeight::Confirmed(1))
+                .expect("should insert tx");
+            cg
+        };
+        let cg2 = {
+            let mut cg = ChainGraph::default();
+            let _ = cg.insert_checkpoint(cp_a).expect("should insert cp");
+            let _ = cg.insert_checkpoint(cp_b2).expect("should insert cp");
+            let _ = cg
+                .insert_tx(tx_b2.clone(), TxHeight::Unconfirmed)
+                .expect("should insert tx");
+            cg
+        };
+
+        let changeset = ChangeSet::<TxHeight> {
+            chain: sparse_chain::ChangeSet {
+                checkpoints: [(1, Some(h!("B'")))].into(),
+                txids: [
+                    (tx_b.txid(), None),
+                    (tx_b2.txid(), Some(TxHeight::Unconfirmed)),
+                ]
+                .into(),
+            },
+            graph: tx_graph::Additions {
+                tx: [tx_b2].into(),
+                txout: [].into(),
+            },
+        };
+        assert_eq!(
+            cg1.determine_changeset(&cg2),
+            Ok(changeset.clone()),
+            "tx should be evicted from B",
+        );
+
+        cg1.apply_changeset(changeset);
+    }
+}
+
+#[test]
+fn chain_graph_new_missing() {
+    let tx_a = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![],
+        output: vec![TxOut::default()],
+    };
+    let tx_b = Transaction {
+        version: 0x02,
+        lock_time: PackedLockTime(0),
+        input: vec![],
+        output: vec![TxOut::default()],
+    };
+
+    let update = chain!(
+        index: TxHeight,
+        checkpoints: [[0, h!("A")]],
+        txids: [
+            (tx_a.txid(), TxHeight::Confirmed(0)),
+            (tx_b.txid(), TxHeight::Confirmed(0))
+        ]
+    );
+    let mut graph = TxGraph::default();
+
+    let mut expected_missing = HashSet::new();
+    expected_missing.insert(tx_a.txid());
+    expected_missing.insert(tx_b.txid());
+
+    assert_eq!(
+        ChainGraph::new(update.clone(), graph.clone()),
+        Err(NewError::Missing(expected_missing.clone()))
+    );
+
+    let _ = graph.insert_tx(tx_b.clone());
+    expected_missing.remove(&tx_b.txid());
+
+    assert_eq!(
+        ChainGraph::new(update.clone(), graph.clone()),
+        Err(NewError::Missing(expected_missing.clone()))
+    );
+
+    let _ = graph.insert_txout(
+        OutPoint {
+            txid: tx_a.txid(),
+            vout: 0,
+        },
+        tx_a.output[0].clone(),
+    );
+
+    assert_eq!(
+        ChainGraph::new(update.clone(), graph.clone()),
+        Err(NewError::Missing(expected_missing)),
+        "inserting an output instead of full tx doesn't satisfy constraint"
+    );
+
+    let _ = graph.insert_tx(tx_a.clone());
+
+    let new_graph = ChainGraph::new(update.clone(), graph.clone()).unwrap();
+    let expected_graph = {
+        let mut cg = ChainGraph::<TxHeight>::default();
+        let _ = cg
+            .insert_checkpoint(update.latest_checkpoint().unwrap())
+            .unwrap();
+        let _ = cg.insert_tx(tx_a, TxHeight::Confirmed(0)).unwrap();
+        let _ = cg.insert_tx(tx_b, TxHeight::Confirmed(0)).unwrap();
+        cg
+    };
+
+    assert_eq!(new_graph, expected_graph);
+}
+
+#[test]
+fn chain_graph_new_conflicts() {
+    let tx_a = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![],
+        output: vec![TxOut::default()],
+    };
+
+    let tx_b = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![TxIn {
+            previous_output: OutPoint::new(tx_a.txid(), 0),
+            script_sig: Script::new(),
+            sequence: Sequence::default(),
+            witness: Witness::new(),
+        }],
+        output: vec![TxOut::default()],
+    };
+
+    let tx_b2 = Transaction {
+        version: 0x02,
+        lock_time: PackedLockTime(0),
+        input: vec![TxIn {
+            previous_output: OutPoint::new(tx_a.txid(), 0),
+            script_sig: Script::new(),
+            sequence: Sequence::default(),
+            witness: Witness::new(),
+        }],
+        output: vec![TxOut::default(), TxOut::default()],
+    };
+
+    let chain = chain!(
+        index: TxHeight,
+        checkpoints: [[5, h!("A")]],
+        txids: [
+            (tx_a.txid(), TxHeight::Confirmed(1)),
+            (tx_b.txid(), TxHeight::Confirmed(2)),
+            (tx_b2.txid(), TxHeight::Confirmed(3))
+        ]
+    );
+
+    let graph = TxGraph::new([tx_a, tx_b, tx_b2]);
+
+    assert!(matches!(
+        ChainGraph::new(chain, graph),
+        Err(NewError::Conflict { .. })
+    ));
+}
+
+#[test]
+fn test_get_tx_in_chain() {
+    let mut cg = ChainGraph::default();
+    let tx = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![],
+        output: vec![TxOut::default()],
+    };
+
+    let _ = cg.insert_tx(tx.clone(), TxHeight::Unconfirmed).unwrap();
+    assert_eq!(
+        cg.get_tx_in_chain(tx.txid()),
+        Some((&TxHeight::Unconfirmed, &tx))
+    );
+}
+
+#[test]
+fn test_iterate_transactions() {
+    let mut cg = ChainGraph::default();
+    let txs = (0..3)
+        .map(|i| Transaction {
+            version: i,
+            lock_time: PackedLockTime(0),
+            input: vec![],
+            output: vec![TxOut::default()],
+        })
+        .collect::<Vec<_>>();
+    let _ = cg
+        .insert_checkpoint(BlockId {
+            height: 1,
+            hash: h!("A"),
+        })
+        .unwrap();
+    let _ = cg
+        .insert_tx(txs[0].clone(), TxHeight::Confirmed(1))
+        .unwrap();
+    let _ = cg.insert_tx(txs[1].clone(), TxHeight::Unconfirmed).unwrap();
+    let _ = cg
+        .insert_tx(txs[2].clone(), TxHeight::Confirmed(0))
+        .unwrap();
+
+    assert_eq!(
+        cg.transactions_in_chain().collect::<Vec<_>>(),
+        vec![
+            (&TxHeight::Confirmed(0), &txs[2]),
+            (&TxHeight::Confirmed(1), &txs[0]),
+            (&TxHeight::Unconfirmed, &txs[1]),
+        ]
+    );
+}
+
+/// Start with: block1, block2a, tx1, tx2a
+///   Update 1: block2a -> block2b , tx2a -> tx2b
+///   Update 2: block2b -> block2c , tx2b -> tx2a
+#[test]
+fn test_apply_changes_reintroduce_tx() {
+    let block1 = BlockId {
+        height: 1,
+        hash: h!("block 1"),
+    };
+    let block2a = BlockId {
+        height: 2,
+        hash: h!("block 2a"),
+    };
+    let block2b = BlockId {
+        height: 2,
+        hash: h!("block 2b"),
+    };
+    let block2c = BlockId {
+        height: 2,
+        hash: h!("block 2c"),
+    };
+
+    let tx1 = Transaction {
+        version: 0,
+        lock_time: PackedLockTime(1),
+        input: Vec::new(),
+        output: [TxOut {
+            value: 1,
+            script_pubkey: Script::new(),
+        }]
+        .into(),
+    };
+
+    let tx2a = Transaction {
+        version: 0,
+        lock_time: PackedLockTime('a'.into()),
+        input: [TxIn {
+            previous_output: OutPoint::new(tx1.txid(), 0),
+            ..Default::default()
+        }]
+        .into(),
+        output: [TxOut {
+            value: 0,
+            ..Default::default()
+        }]
+        .into(),
+    };
+
+    let tx2b = Transaction {
+        lock_time: PackedLockTime('b'.into()),
+        ..tx2a.clone()
+    };
+
+    // block1, block2a, tx1, tx2a
+    let mut cg = {
+        let mut cg = ChainGraph::default();
+        let _ = cg.insert_checkpoint(block1).unwrap();
+        let _ = cg.insert_checkpoint(block2a).unwrap();
+        let _ = cg.insert_tx(tx1, TxHeight::Confirmed(1)).unwrap();
+        let _ = cg.insert_tx(tx2a.clone(), TxHeight::Confirmed(2)).unwrap();
+        cg
+    };
+
+    // block2a -> block2b , tx2a -> tx2b
+    let update = {
+        let mut update = ChainGraph::default();
+        let _ = update.insert_checkpoint(block1).unwrap();
+        let _ = update.insert_checkpoint(block2b).unwrap();
+        let _ = update
+            .insert_tx(tx2b.clone(), TxHeight::Confirmed(2))
+            .unwrap();
+        update
+    };
+    assert_eq!(
+        cg.apply_update(update).expect("should update"),
+        ChangeSet {
+            chain: changeset! {
+                checkpoints: [(2, Some(block2b.hash))],
+                txids: [(tx2a.txid(), None), (tx2b.txid(), Some(TxHeight::Confirmed(2)))]
+            },
+            graph: tx_graph::Additions {
+                tx: [tx2b.clone()].into(),
+                ..Default::default()
+            },
+        }
+    );
+
+    // block2b -> block2c , tx2b -> tx2a
+    let update = {
+        let mut update = ChainGraph::default();
+        let _ = update.insert_checkpoint(block1).unwrap();
+        let _ = update.insert_checkpoint(block2c).unwrap();
+        let _ = update
+            .insert_tx(tx2a.clone(), TxHeight::Confirmed(2))
+            .unwrap();
+        update
+    };
+    assert_eq!(
+        cg.apply_update(update).expect("should update"),
+        ChangeSet {
+            chain: changeset! {
+                checkpoints: [(2, Some(block2c.hash))],
+                txids: [(tx2b.txid(), None), (tx2a.txid(), Some(TxHeight::Confirmed(2)))]
+            },
+            ..Default::default()
+        }
+    );
+}
+
+#[test]
+fn test_evict_descendants() {
+    let block_1 = BlockId {
+        height: 1,
+        hash: h!("block 1"),
+    };
+
+    let block_2a = BlockId {
+        height: 2,
+        hash: h!("block 2 a"),
+    };
+
+    let block_2b = BlockId {
+        height: 2,
+        hash: h!("block 2 b"),
+    };
+
+    let tx_1 = Transaction {
+        input: vec![TxIn {
+            previous_output: OutPoint::new(h!("fake tx"), 0),
+            ..Default::default()
+        }],
+        output: vec![TxOut {
+            value: 10_000,
+            script_pubkey: Script::new(),
+        }],
+        ..common::new_tx(1)
+    };
+    let tx_2 = Transaction {
+        input: vec![TxIn {
+            previous_output: OutPoint::new(tx_1.txid(), 0),
+            ..Default::default()
+        }],
+        output: vec![
+            TxOut {
+                value: 20_000,
+                script_pubkey: Script::new(),
+            },
+            TxOut {
+                value: 30_000,
+                script_pubkey: Script::new(),
+            },
+        ],
+        ..common::new_tx(2)
+    };
+    let tx_3 = Transaction {
+        input: vec![TxIn {
+            previous_output: OutPoint::new(tx_2.txid(), 0),
+            ..Default::default()
+        }],
+        output: vec![TxOut {
+            value: 40_000,
+            script_pubkey: Script::new(),
+        }],
+        ..common::new_tx(3)
+    };
+    let tx_4 = Transaction {
+        input: vec![TxIn {
+            previous_output: OutPoint::new(tx_2.txid(), 1),
+            ..Default::default()
+        }],
+        output: vec![TxOut {
+            value: 40_000,
+            script_pubkey: Script::new(),
+        }],
+        ..common::new_tx(4)
+    };
+    let tx_5 = Transaction {
+        input: vec![TxIn {
+            previous_output: OutPoint::new(tx_4.txid(), 0),
+            ..Default::default()
+        }],
+        output: vec![TxOut {
+            value: 40_000,
+            script_pubkey: Script::new(),
+        }],
+        ..common::new_tx(5)
+    };
+
+    let tx_conflict = Transaction {
+        input: vec![TxIn {
+            previous_output: OutPoint::new(tx_1.txid(), 0),
+            ..Default::default()
+        }],
+        output: vec![TxOut {
+            value: 12345,
+            script_pubkey: Script::new(),
+        }],
+        ..common::new_tx(6)
+    };
+
+    // 1 is spent by 2, 2 is spent by 3 and 4, 4 is spent by 5
+    let _txid_1 = tx_1.txid();
+    let txid_2 = tx_2.txid();
+    let txid_3 = tx_3.txid();
+    let txid_4 = tx_4.txid();
+    let txid_5 = tx_5.txid();
+
+    // this tx conflicts with 2
+    let txid_conflict = tx_conflict.txid();
+
+    let cg = {
+        let mut cg = ChainGraph::<TxHeight>::default();
+        let _ = cg.insert_checkpoint(block_1);
+        let _ = cg.insert_checkpoint(block_2a);
+        let _ = cg.insert_tx(tx_1, TxHeight::Confirmed(1));
+        let _ = cg.insert_tx(tx_2, TxHeight::Confirmed(2));
+        let _ = cg.insert_tx(tx_3, TxHeight::Confirmed(2));
+        let _ = cg.insert_tx(tx_4, TxHeight::Confirmed(2));
+        let _ = cg.insert_tx(tx_5, TxHeight::Confirmed(2));
+        cg
+    };
+
+    let update = {
+        let mut cg = ChainGraph::<TxHeight>::default();
+        let _ = cg.insert_checkpoint(block_1);
+        let _ = cg.insert_checkpoint(block_2b);
+        let _ = cg.insert_tx(tx_conflict.clone(), TxHeight::Confirmed(2));
+        cg
+    };
+
+    assert_eq!(
+        cg.determine_changeset(&update),
+        Ok(ChangeSet {
+            chain: changeset! {
+                checkpoints: [(2, Some(block_2b.hash))],
+                txids: [(txid_2, None), (txid_3, None), (txid_4, None), (txid_5, None), (txid_conflict, Some(TxHeight::Confirmed(2)))]
+            },
+            graph: tx_graph::Additions {
+                tx: [tx_conflict.clone()].into(),
+                ..Default::default()
+            }
+        })
+    );
+
+    let err = cg
+        .insert_tx_preview(tx_conflict, TxHeight::Unconfirmed)
+        .expect_err("must fail due to conflicts");
+    assert!(matches!(err, InsertTxError::UnresolvableConflict(_)));
+}
--- a/crates/chain/tests/test_indexed_tx_graph.rs
+++ b/crates/chain/tests/test_indexed_tx_graph.rs
@@ -1,465 +0,0 @@
-#[macro_use]
-mod common;
-
-use std::{collections::BTreeSet, sync::Arc};
-
-use bdk_chain::{
-    indexed_tx_graph::{self, IndexedTxGraph},
-    keychain::{self, Balance, KeychainTxOutIndex},
-    local_chain::LocalChain,
-    tx_graph, ChainPosition, ConfirmationHeightAnchor,
-};
-use bitcoin::{
-    secp256k1::Secp256k1, Amount, OutPoint, Script, ScriptBuf, Transaction, TxIn, TxOut,
-};
-use miniscript::Descriptor;
-
-/// Ensure [`IndexedTxGraph::insert_relevant_txs`] can successfully index transactions NOT presented
-/// in topological order.
-///
-/// Given 3 transactions (A, B, C), where A has 2 owned outputs. B and C spends an output each of A.
-/// Typically, we would only know whether B and C are relevant if we have indexed A (A's outpoints
-/// are associated with owned spks in the index). Ensure insertion and indexing is topological-
-/// agnostic.
-#[test]
-fn insert_relevant_txs() {
-    const DESCRIPTOR: &str = "tr([73c5da0a/86'/0'/0']xprv9xgqHN7yz9MwCkxsBPN5qetuNdQSUttZNKw1dcYTV4mkaAFiBVGQziHs3NRSWMkCzvgjEe3n9xV8oYywvM8at9yRqyaZVz6TYYhX98VjsUk/0/*)";
-    let (descriptor, _) = Descriptor::parse_descriptor(&Secp256k1::signing_only(), DESCRIPTOR)
-        .expect("must be valid");
-    let spk_0 = descriptor.at_derivation_index(0).unwrap().script_pubkey();
-    let spk_1 = descriptor.at_derivation_index(9).unwrap().script_pubkey();
-
-    let mut graph = IndexedTxGraph::<ConfirmationHeightAnchor, KeychainTxOutIndex<()>>::new(
-        KeychainTxOutIndex::new(10),
-    );
-    graph.index.add_keychain((), descriptor);
-
-    let tx_a = Transaction {
-        output: vec![
-            TxOut {
-                value: Amount::from_sat(10_000),
-                script_pubkey: spk_0,
-            },
-            TxOut {
-                value: Amount::from_sat(20_000),
-                script_pubkey: spk_1,
-            },
-        ],
-        ..common::new_tx(0)
-    };
-
-    let tx_b = Transaction {
-        input: vec![TxIn {
-            previous_output: OutPoint::new(tx_a.txid(), 0),
-            ..Default::default()
-        }],
-        ..common::new_tx(1)
-    };
-
-    let tx_c = Transaction {
-        input: vec![TxIn {
-            previous_output: OutPoint::new(tx_a.txid(), 1),
-            ..Default::default()
-        }],
-        ..common::new_tx(2)
-    };
-
-    let txs = [tx_c, tx_b, tx_a];
-
-    let changeset = indexed_tx_graph::ChangeSet {
-        graph: tx_graph::ChangeSet {
-            txs: txs.iter().cloned().map(Arc::new).collect(),
-            ..Default::default()
-        },
-        indexer: keychain::ChangeSet([((), 9_u32)].into()),
-    };
-
-    assert_eq!(
-        graph.batch_insert_relevant(txs.iter().map(|tx| (tx, None))),
-        changeset,
-    );
-
-    assert_eq!(graph.initial_changeset(), changeset,);
-}
-
-/// Ensure consistency IndexedTxGraph list_* and balance methods. These methods lists
-/// relevant txouts and utxos from the information fetched from a ChainOracle (here a LocalChain).
-///
-/// Test Setup:
-///
-/// Local Chain =>  <0> ----- <1> ----- <2> ----- <3> ---- ... ---- <150>
-///
-/// Keychains:
-///
-/// keychain_1: Trusted
-/// keychain_2: Untrusted
-///
-/// Transactions:
-///
-/// tx1: A Coinbase, sending 70000 sats to "trusted" address. [Block 0]
-/// tx2: A external Receive, sending 30000 sats to "untrusted" address. [Block 1]
-/// tx3: Internal Spend. Spends tx2 and returns change of 10000 to "trusted" address. [Block 2]
-/// tx4: Mempool tx, sending 20000 sats to "trusted" address.
-/// tx5: Mempool tx, sending 15000 sats to "untested" address.
-/// tx6: Complete unrelated tx. [Block 3]
-///
-/// Different transactions are added via `insert_relevant_txs`.
-/// `list_owned_txout`, `list_owned_utxos` and `balance` method is asserted
-/// with expected values at Block height 0, 1, and 2.
-///
-/// Finally Add more blocks to local chain until tx1 coinbase maturity hits.
-/// Assert maturity at coinbase maturity inflection height. Block height 98 and 99.
-#[test]
-fn test_list_owned_txouts() {
-    // Create Local chains
-    let local_chain = LocalChain::from_blocks((0..150).map(|i| (i as u32, h!("random"))).collect())
-        .expect("must have genesis hash");
-
-    // Initiate IndexedTxGraph
-
-    let (desc_1, _) = Descriptor::parse_descriptor(&Secp256k1::signing_only(), "tr(tprv8ZgxMBicQKsPd3krDUsBAmtnRsK3rb8u5yi1zhQgMhF1tR8MW7xfE4rnrbbsrbPR52e7rKapu6ztw1jXveJSCGHEriUGZV7mCe88duLp5pj/86'/1'/0'/0/*)").unwrap();
-    let (desc_2, _) = Descriptor::parse_descriptor(&Secp256k1::signing_only(), "tr(tprv8ZgxMBicQKsPd3krDUsBAmtnRsK3rb8u5yi1zhQgMhF1tR8MW7xfE4rnrbbsrbPR52e7rKapu6ztw1jXveJSCGHEriUGZV7mCe88duLp5pj/86'/1'/0'/1/*)").unwrap();
-
-    let mut graph = IndexedTxGraph::<ConfirmationHeightAnchor, KeychainTxOutIndex<String>>::new(
-        KeychainTxOutIndex::new(10),
-    );
-
-    graph.index.add_keychain("keychain_1".into(), desc_1);
-    graph.index.add_keychain("keychain_2".into(), desc_2);
-
-    // Get trusted and untrusted addresses
-
-    let mut trusted_spks: Vec<ScriptBuf> = Vec::new();
-    let mut untrusted_spks: Vec<ScriptBuf> = Vec::new();
-
-    {
-        // we need to scope here to take immutanble reference of the graph
-        for _ in 0..10 {
-            let ((_, script), _) = graph.index.reveal_next_spk(&"keychain_1".to_string());
-            // TODO Assert indexes
-            trusted_spks.push(script.to_owned());
-        }
-    }
-    {
-        for _ in 0..10 {
-            let ((_, script), _) = graph.index.reveal_next_spk(&"keychain_2".to_string());
-            untrusted_spks.push(script.to_owned());
-        }
-    }
-
-    // Create test transactions
-
-    // tx1 is the genesis coinbase
-    let tx1 = Transaction {
-        input: vec![TxIn {
-            previous_output: OutPoint::null(),
-            ..Default::default()
-        }],
-        output: vec![TxOut {
-            value: Amount::from_sat(70000),
-            script_pubkey: trusted_spks[0].to_owned(),
-        }],
-        ..common::new_tx(0)
-    };
-
-    // tx2 is an incoming transaction received at untrusted keychain at block 1.
-    let tx2 = Transaction {
-        output: vec![TxOut {
-            value: Amount::from_sat(30000),
-            script_pubkey: untrusted_spks[0].to_owned(),
-        }],
-        ..common::new_tx(0)
-    };
-
-    // tx3 spends tx2 and gives a change back in trusted keychain. Confirmed at Block 2.
-    let tx3 = Transaction {
-        input: vec![TxIn {
-            previous_output: OutPoint::new(tx2.txid(), 0),
-            ..Default::default()
-        }],
-        output: vec![TxOut {
-            value: Amount::from_sat(10000),
-            script_pubkey: trusted_spks[1].to_owned(),
-        }],
-        ..common::new_tx(0)
-    };
-
-    // tx4 is an external transaction receiving at untrusted keychain, unconfirmed.
-    let tx4 = Transaction {
-        output: vec![TxOut {
-            value: Amount::from_sat(20000),
-            script_pubkey: untrusted_spks[1].to_owned(),
-        }],
-        ..common::new_tx(0)
-    };
-
-    // tx5 is spending tx3 and receiving change at trusted keychain, unconfirmed.
-    let tx5 = Transaction {
-        output: vec![TxOut {
-            value: Amount::from_sat(15000),
-            script_pubkey: trusted_spks[2].to_owned(),
-        }],
-        ..common::new_tx(0)
-    };
-
-    // tx6 is an unrelated transaction confirmed at 3.
-    let tx6 = common::new_tx(0);
-
-    // Insert transactions into graph with respective anchors
-    // For unconfirmed txs we pass in `None`.
-
-    let _ =
-        graph.batch_insert_relevant([&tx1, &tx2, &tx3, &tx6].iter().enumerate().map(|(i, tx)| {
-            let height = i as u32;
-            (
-                *tx,
-                local_chain
-                    .get(height)
-                    .map(|cp| cp.block_id())
-                    .map(|anchor_block| ConfirmationHeightAnchor {
-                        anchor_block,
-                        confirmation_height: anchor_block.height,
-                    }),
-            )
-        }));
-
-    let _ = graph.batch_insert_relevant_unconfirmed([&tx4, &tx5].iter().map(|tx| (*tx, 100)));
-
-    // A helper lambda to extract and filter data from the graph.
-    let fetch =
-        |height: u32,
-         graph: &IndexedTxGraph<ConfirmationHeightAnchor, KeychainTxOutIndex<String>>| {
-            let chain_tip = local_chain
-                .get(height)
-                .map(|cp| cp.block_id())
-                .unwrap_or_else(|| panic!("block must exist at {}", height));
-            let txouts = graph
-                .graph()
-                .filter_chain_txouts(
-                    &local_chain,
-                    chain_tip,
-                    graph.index.outpoints().iter().cloned(),
-                )
-                .collect::<Vec<_>>();
-
-            let utxos = graph
-                .graph()
-                .filter_chain_unspents(
-                    &local_chain,
-                    chain_tip,
-                    graph.index.outpoints().iter().cloned(),
-                )
-                .collect::<Vec<_>>();
-
-            let balance = graph.graph().balance(
-                &local_chain,
-                chain_tip,
-                graph.index.outpoints().iter().cloned(),
-                |_, spk: &Script| trusted_spks.contains(&spk.to_owned()),
-            );
-
-            assert_eq!(txouts.len(), 5);
-            assert_eq!(utxos.len(), 4);
-
-            let confirmed_txouts_txid = txouts
-                .iter()
-                .filter_map(|(_, full_txout)| {
-                    if matches!(full_txout.chain_position, ChainPosition::Confirmed(_)) {
-                        Some(full_txout.outpoint.txid)
-                    } else {
-                        None
-                    }
-                })
-                .collect::<BTreeSet<_>>();
-
-            let unconfirmed_txouts_txid = txouts
-                .iter()
-                .filter_map(|(_, full_txout)| {
-                    if matches!(full_txout.chain_position, ChainPosition::Unconfirmed(_)) {
-                        Some(full_txout.outpoint.txid)
-                    } else {
-                        None
-                    }
-                })
-                .collect::<BTreeSet<_>>();
-
-            let confirmed_utxos_txid = utxos
-                .iter()
-                .filter_map(|(_, full_txout)| {
-                    if matches!(full_txout.chain_position, ChainPosition::Confirmed(_)) {
-                        Some(full_txout.outpoint.txid)
-                    } else {
-                        None
-                    }
-                })
-                .collect::<BTreeSet<_>>();
-
-            let unconfirmed_utxos_txid = utxos
-                .iter()
-                .filter_map(|(_, full_txout)| {
-                    if matches!(full_txout.chain_position, ChainPosition::Unconfirmed(_)) {
-                        Some(full_txout.outpoint.txid)
-                    } else {
-                        None
-                    }
-                })
-                .collect::<BTreeSet<_>>();
-
-            (
-                confirmed_txouts_txid,
-                unconfirmed_txouts_txid,
-                confirmed_utxos_txid,
-                unconfirmed_utxos_txid,
-                balance,
-            )
-        };
-
-    // ----- TEST BLOCK -----
-
-    // AT Block 0
-    {
-        let (
-            confirmed_txouts_txid,
-            unconfirmed_txouts_txid,
-            confirmed_utxos_txid,
-            unconfirmed_utxos_txid,
-            balance,
-        ) = fetch(0, &graph);
-
-        assert_eq!(confirmed_txouts_txid, [tx1.txid()].into());
-        assert_eq!(
-            unconfirmed_txouts_txid,
-            [tx2.txid(), tx3.txid(), tx4.txid(), tx5.txid()].into()
-        );
-
-        assert_eq!(confirmed_utxos_txid, [tx1.txid()].into());
-        assert_eq!(
-            unconfirmed_utxos_txid,
-            [tx3.txid(), tx4.txid(), tx5.txid()].into()
-        );
-
-        assert_eq!(
-            balance,
-            Balance {
-                immature: 70000,          // immature coinbase
-                trusted_pending: 25000,   // tx3 + tx5
-                untrusted_pending: 20000, // tx4
-                confirmed: 0              // Nothing is confirmed yet
-            }
-        );
-    }
-
-    // AT Block 1
-    {
-        let (
-            confirmed_txouts_txid,
-            unconfirmed_txouts_txid,
-            confirmed_utxos_txid,
-            unconfirmed_utxos_txid,
-            balance,
-        ) = fetch(1, &graph);
-
-        // tx2 gets into confirmed txout set
-        assert_eq!(confirmed_txouts_txid, [tx1.txid(), tx2.txid()].into());
-        assert_eq!(
-            unconfirmed_txouts_txid,
-            [tx3.txid(), tx4.txid(), tx5.txid()].into()
-        );
-
-        // tx2 doesn't get into confirmed utxos set
-        assert_eq!(confirmed_utxos_txid, [tx1.txid()].into());
-        assert_eq!(
-            unconfirmed_utxos_txid,
-            [tx3.txid(), tx4.txid(), tx5.txid()].into()
-        );
-
-        assert_eq!(
-            balance,
-            Balance {
-                immature: 70000,          // immature coinbase
-                trusted_pending: 25000,   // tx3 + tx5
-                untrusted_pending: 20000, // tx4
-                confirmed: 0              // Nothing is confirmed yet
-            }
-        );
-    }
-
-    // AT Block 2
-    {
-        let (
-            confirmed_txouts_txid,
-            unconfirmed_txouts_txid,
-            confirmed_utxos_txid,
-            unconfirmed_utxos_txid,
-            balance,
-        ) = fetch(2, &graph);
-
-        // tx3 now gets into the confirmed txout set
-        assert_eq!(
-            confirmed_txouts_txid,
-            [tx1.txid(), tx2.txid(), tx3.txid()].into()
-        );
-        assert_eq!(unconfirmed_txouts_txid, [tx4.txid(), tx5.txid()].into());
-
-        // tx3 also gets into confirmed utxo set
-        assert_eq!(confirmed_utxos_txid, [tx1.txid(), tx3.txid()].into());
-        assert_eq!(unconfirmed_utxos_txid, [tx4.txid(), tx5.txid()].into());
-
-        assert_eq!(
-            balance,
-            Balance {
-                immature: 70000,          // immature coinbase
-                trusted_pending: 15000,   // tx5
-                untrusted_pending: 20000, // tx4
-                confirmed: 10000          // tx3 got confirmed
-            }
-        );
-    }
-
-    // AT Block 98
-    {
-        let (
-            confirmed_txouts_txid,
-            unconfirmed_txouts_txid,
-            confirmed_utxos_txid,
-            unconfirmed_utxos_txid,
-            balance,
-        ) = fetch(98, &graph);
-
-        assert_eq!(
-            confirmed_txouts_txid,
-            [tx1.txid(), tx2.txid(), tx3.txid()].into()
-        );
-        assert_eq!(unconfirmed_txouts_txid, [tx4.txid(), tx5.txid()].into());
-
-        assert_eq!(confirmed_utxos_txid, [tx1.txid(), tx3.txid()].into());
-        assert_eq!(unconfirmed_utxos_txid, [tx4.txid(), tx5.txid()].into());
-
-        // Coinbase is still immature
-        assert_eq!(
-            balance,
-            Balance {
-                immature: 70000,          // immature coinbase
-                trusted_pending: 15000,   // tx5
-                untrusted_pending: 20000, // tx4
-                confirmed: 10000          // tx1 got matured
-            }
-        );
-    }
-
-    // AT Block 99
-    {
-        let (_, _, _, _, balance) = fetch(100, &graph);
-
-        // Coinbase maturity hits
-        assert_eq!(
-            balance,
-            Balance {
-                immature: 0,              // coinbase matured
-                trusted_pending: 15000,   // tx5
-                untrusted_pending: 20000, // tx4
-                confirmed: 80000          // tx1 + tx3
-            }
-        );
-    }
-}
--- a/crates/chain/tests/test_keychain_tracker.rs
+++ b/crates/chain/tests/test_keychain_tracker.rs
@@ -0,0 +1,239 @@
+#![cfg(feature = "miniscript")]
+#[macro_use]
+mod common;
+use bdk_chain::{
+    keychain::{Balance, KeychainTracker},
+    miniscript::{
+        bitcoin::{secp256k1::Secp256k1, OutPoint, PackedLockTime, Transaction, TxOut},
+        Descriptor,
+    },
+    BlockId, ConfirmationTime, TxHeight,
+};
+use bitcoin::TxIn;
+
+#[test]
+fn test_insert_tx() {
+    let mut tracker = KeychainTracker::default();
+    let secp = Secp256k1::new();
+    let (descriptor, _) = Descriptor::parse_descriptor(&secp, "tr([73c5da0a/86'/0'/0']xprv9xgqHN7yz9MwCkxsBPN5qetuNdQSUttZNKw1dcYTV4mkaAFiBVGQziHs3NRSWMkCzvgjEe3n9xV8oYywvM8at9yRqyaZVz6TYYhX98VjsUk/0/*)").unwrap();
+    tracker.add_keychain((), descriptor.clone());
+    let txout = TxOut {
+        value: 100_000,
+        script_pubkey: descriptor.at_derivation_index(5).script_pubkey(),
+    };
+
+    let tx = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![],
+        output: vec![txout],
+    };
+
+    let _ = tracker.txout_index.reveal_to_target(&(), 5);
+
+    let changeset = tracker
+        .insert_tx_preview(tx.clone(), ConfirmationTime::Unconfirmed)
+        .unwrap();
+    tracker.apply_changeset(changeset);
+    assert_eq!(
+        tracker
+            .chain_graph()
+            .transactions_in_chain()
+            .collect::<Vec<_>>(),
+        vec![(&ConfirmationTime::Unconfirmed, &tx)]
+    );
+
+    assert_eq!(
+        tracker
+            .txout_index
+            .txouts_of_keychain(&())
+            .collect::<Vec<_>>(),
+        vec![(
+            5,
+            OutPoint {
+                txid: tx.txid(),
+                vout: 0
+            }
+        )]
+    );
+}
+
+#[test]
+fn test_balance() {
+    use core::str::FromStr;
+    #[derive(Debug, Clone, PartialEq, Eq, Ord, PartialOrd)]
+    enum Keychain {
+        One,
+        Two,
+    }
+    let mut tracker = KeychainTracker::<Keychain, TxHeight>::default();
+    let one = Descriptor::from_str("tr([73c5da0a/86'/0'/0']xpub6BgBgsespWvERF3LHQu6CnqdvfEvtMcQjYrcRzx53QJjSxarj2afYWcLteoGVky7D3UKDP9QyrLprQ3VCECoY49yfdDEHGCtMMj92pReUsQ/0/*)#rg247h69").unwrap();
+    let two = Descriptor::from_str("tr([73c5da0a/86'/0'/0']xpub6BgBgsespWvERF3LHQu6CnqdvfEvtMcQjYrcRzx53QJjSxarj2afYWcLteoGVky7D3UKDP9QyrLprQ3VCECoY49yfdDEHGCtMMj92pReUsQ/1/*)#ju05rz2a").unwrap();
+    tracker.add_keychain(Keychain::One, one);
+    tracker.add_keychain(Keychain::Two, two);
+
+    let tx1 = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![],
+        output: vec![TxOut {
+            value: 13_000,
+            script_pubkey: tracker
+                .txout_index
+                .reveal_next_spk(&Keychain::One)
+                .0
+                 .1
+                .clone(),
+        }],
+    };
+
+    let tx2 = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![],
+        output: vec![TxOut {
+            value: 7_000,
+            script_pubkey: tracker
+                .txout_index
+                .reveal_next_spk(&Keychain::Two)
+                .0
+                 .1
+                .clone(),
+        }],
+    };
+
+    let tx_coinbase = Transaction {
+        version: 0x01,
+        lock_time: PackedLockTime(0),
+        input: vec![TxIn::default()],
+        output: vec![TxOut {
+            value: 11_000,
+            script_pubkey: tracker
+                .txout_index
+                .reveal_next_spk(&Keychain::Two)
+                .0
+                 .1
+                .clone(),
+        }],
+    };
+
+    assert!(tx_coinbase.is_coin_base());
+
+    let _ = tracker
+        .insert_checkpoint(BlockId {
+            height: 5,
+            hash: h!("1"),
+        })
+        .unwrap();
+
+    let should_trust = |keychain: &Keychain| match *keychain {
+        Keychain::One => false,
+        Keychain::Two => true,
+    };
+
+    assert_eq!(tracker.balance(should_trust), Balance::default());
+
+    let _ = tracker
+        .insert_tx(tx1.clone(), TxHeight::Unconfirmed)
+        .unwrap();
+
+    assert_eq!(
+        tracker.balance(should_trust),
+        Balance {
+            untrusted_pending: 13_000,
+            ..Default::default()
+        }
+    );
+
+    let _ = tracker
+        .insert_tx(tx2.clone(), TxHeight::Unconfirmed)
+        .unwrap();
+
+    assert_eq!(
+        tracker.balance(should_trust),
+        Balance {
+            trusted_pending: 7_000,
+            untrusted_pending: 13_000,
+            ..Default::default()
+        }
+    );
+
+    let _ = tracker
+        .insert_tx(tx_coinbase, TxHeight::Confirmed(0))
+        .unwrap();
+
+    assert_eq!(
+        tracker.balance(should_trust),
+        Balance {
+            trusted_pending: 7_000,
+            untrusted_pending: 13_000,
+            immature: 11_000,
+            ..Default::default()
+        }
+    );
+
+    let _ = tracker.insert_tx(tx1, TxHeight::Confirmed(1)).unwrap();
+
+    assert_eq!(
+        tracker.balance(should_trust),
+        Balance {
+            trusted_pending: 7_000,
+            untrusted_pending: 0,
+            immature: 11_000,
+            confirmed: 13_000,
+        }
+    );
+
+    let _ = tracker.insert_tx(tx2, TxHeight::Confirmed(2)).unwrap();
+
+    assert_eq!(
+        tracker.balance(should_trust),
+        Balance {
+            trusted_pending: 0,
+            untrusted_pending: 0,
+            immature: 11_000,
+            confirmed: 20_000,
+        }
+    );
+
+    let _ = tracker
+        .insert_checkpoint(BlockId {
+            height: 98,
+            hash: h!("98"),
+        })
+        .unwrap();
+
+    assert_eq!(
+        tracker.balance(should_trust),
+        Balance {
+            trusted_pending: 0,
+            untrusted_pending: 0,
+            immature: 11_000,
+            confirmed: 20_000,
+        }
+    );
+
+    let _ = tracker
+        .insert_checkpoint(BlockId {
+            height: 99,
+            hash: h!("99"),
+        })
+        .unwrap();
+
+    assert_eq!(
+        tracker.balance(should_trust),
+        Balance {
+            trusted_pending: 0,
+            untrusted_pending: 0,
+            immature: 0,
+            confirmed: 31_000,
+        }
+    );
+
+    assert_eq!(tracker.balance_at(0), 0);
+    assert_eq!(tracker.balance_at(1), 13_000);
+    assert_eq!(tracker.balance_at(2), 20_000);
+    assert_eq!(tracker.balance_at(98), 20_000);
+    assert_eq!(tracker.balance_at(99), 31_000);
+    assert_eq!(tracker.balance_at(100), 31_000);
+}
--- a/crates/chain/tests/test_keychain_txout_index.rs
+++ b/crates/chain/tests/test_keychain_txout_index.rs
@@ -4,12 +4,10 @@
 mod common;
 use bdk_chain::{
    collections::BTreeMap,
-    indexed_tx_graph::Indexer,
-    keychain::{self, KeychainTxOutIndex},
-    Append,
+    keychain::{DerivationAdditions, KeychainTxOutIndex},
 };

-use bitcoin::{secp256k1::Secp256k1, Amount, OutPoint, ScriptBuf, Transaction, TxOut};
+use bitcoin::{secp256k1::Secp256k1, OutPoint, Script, Transaction, TxOut};
 use miniscript::{Descriptor, DescriptorPublicKey};

 #[derive(Clone, Debug, PartialEq, Eq, Ord, PartialOrd)]
@@ -18,14 +16,12 @@ enum TestKeychain {
    Internal,
 }

-fn init_txout_index(
-    lookahead: u32,
-) -> (
+fn init_txout_index() -> (
    bdk_chain::keychain::KeychainTxOutIndex<TestKeychain>,
    Descriptor<DescriptorPublicKey>,
    Descriptor<DescriptorPublicKey>,
 ) {
-    let mut txout_index = bdk_chain::keychain::KeychainTxOutIndex::<TestKeychain>::new(lookahead);
+    let mut txout_index = bdk_chain::keychain::KeychainTxOutIndex::<TestKeychain>::default();

    let secp = bdk_chain::bitcoin::secp256k1::Secp256k1::signing_only();
    let (external_descriptor,_) = Descriptor::<DescriptorPublicKey>::parse_descriptor(&secp, "tr([73c5da0a/86'/0'/0']xprv9xgqHN7yz9MwCkxsBPN5qetuNdQSUttZNKw1dcYTV4mkaAFiBVGQziHs3NRSWMkCzvgjEe3n9xV8oYywvM8at9yRqyaZVz6TYYhX98VjsUk/0/*)").unwrap();
@@ -37,7 +33,7 @@ fn init_txout_index(
    (txout_index, external_descriptor, internal_descriptor)
 }

-fn spk_at_index(descriptor: &Descriptor<DescriptorPublicKey>, index: u32) -> ScriptBuf {
+fn spk_at_index(descriptor: &Descriptor<DescriptorPublicKey>, index: u32) -> Script {
    descriptor
        .derived_descriptor(&Secp256k1::verification_only(), index)
        .expect("must derive")
@@ -46,9 +42,7 @@ fn spk_at_index(descriptor: &Descriptor<DescriptorPublicKey>, index: u32) -> Scr

 #[test]
 fn test_set_all_derivation_indices() {
-    use bdk_chain::indexed_tx_graph::Indexer;
-
-    let (mut txout_index, _, _) = init_txout_index(0);
+    let (mut txout_index, _, _) = init_txout_index();
    let derive_to: BTreeMap<_, _> =
        [(TestKeychain::External, 12), (TestKeychain::Internal, 24)].into();
    assert_eq!(
@@ -58,75 +52,83 @@ fn test_set_all_derivation_indices() {
    assert_eq!(txout_index.last_revealed_indices(), &derive_to);
    assert_eq!(
        txout_index.reveal_to_target_multi(&derive_to).1,
-        keychain::ChangeSet::default(),
+        DerivationAdditions::default(),
        "no changes if we set to the same thing"
    );
-    assert_eq!(txout_index.initial_changeset().as_inner(), &derive_to);
 }

 #[test]
 fn test_lookahead() {
-    let (mut txout_index, external_desc, internal_desc) = init_txout_index(10);
+    let (mut txout_index, external_desc, internal_desc) = init_txout_index();
+
+    // ensure it does not break anything if lookahead is set multiple times
+    (0..=10).for_each(|lookahead| txout_index.set_lookahead(&TestKeychain::External, lookahead));
+    (0..=20)
+        .filter(|v| v % 2 == 0)
+        .for_each(|lookahead| txout_index.set_lookahead(&TestKeychain::Internal, lookahead));
+
+    assert_eq!(txout_index.inner().all_spks().len(), 30);

    // given:
    // - external lookahead set to 10
+    // - internal lookahead set to 20
    // when:
    // - set external derivation index to value higher than last, but within the lookahead value
    // expect:
    // - scripts cached in spk_txout_index should increase correctly
    // - stored scripts of external keychain should be of expected counts
    for index in (0..20).skip_while(|i| i % 2 == 1) {
-        let (revealed_spks, revealed_changeset) =
+        let (revealed_spks, revealed_additions) =
            txout_index.reveal_to_target(&TestKeychain::External, index);
        assert_eq!(
            revealed_spks.collect::<Vec<_>>(),
            vec![(index, spk_at_index(&external_desc, index))],
        );
        assert_eq!(
-            revealed_changeset.as_inner(),
+            revealed_additions.as_inner(),
            &[(TestKeychain::External, index)].into()
        );

        assert_eq!(
            txout_index.inner().all_spks().len(),
            10 /* external lookahead */ +
-            10 /* internal lookahead */ +
+            20 /* internal lookahead */ +
            index as usize + 1 /* `derived` count */
        );
        assert_eq!(
            txout_index
-                .revealed_keychain_spks(&TestKeychain::External)
+                .revealed_spks_of_keychain(&TestKeychain::External)
                .count(),
            index as usize + 1,
        );
        assert_eq!(
            txout_index
-                .revealed_keychain_spks(&TestKeychain::Internal)
+                .revealed_spks_of_keychain(&TestKeychain::Internal)
                .count(),
            0,
        );
        assert_eq!(
            txout_index
-                .unused_keychain_spks(&TestKeychain::External)
+                .unused_spks_of_keychain(&TestKeychain::External)
                .count(),
            index as usize + 1,
        );
        assert_eq!(
            txout_index
-                .unused_keychain_spks(&TestKeychain::Internal)
+                .unused_spks_of_keychain(&TestKeychain::Internal)
                .count(),
            0,
        );
    }

    // given:
-    // - internal lookahead is 10
+    // - internal lookahead is 20
    // - internal derivation index is `None`
    // when:
    // - derivation index is set ahead of current derivation index + lookahead
    // expect:
    // - scripts cached in spk_txout_index should increase correctly, a.k.a. no scripts are skipped
-    let (revealed_spks, revealed_changeset) =
+    let (revealed_spks, revealed_additions) =
        txout_index.reveal_to_target(&TestKeychain::Internal, 24);
    assert_eq!(
        revealed_spks.collect::<Vec<_>>(),
@@ -135,19 +137,19 @@ fn test_lookahead() {
            .collect::<Vec<_>>(),
    );
    assert_eq!(
-        revealed_changeset.as_inner(),
+        revealed_additions.as_inner(),
        &[(TestKeychain::Internal, 24)].into()
    );
    assert_eq!(
        txout_index.inner().all_spks().len(),
        10 /* external lookahead */ +
-        10 /* internal lookahead */ +
+        20 /* internal lookahead */ +
        20 /* external stored index count */ +
        25 /* internal stored index count */
    );
    assert_eq!(
        txout_index
-            .revealed_keychain_spks(&TestKeychain::Internal)
+            .revealed_spks_of_keychain(&TestKeychain::Internal)
            .count(),
        25,
    );
@@ -174,21 +176,19 @@ fn test_lookahead() {
                TxOut {
                    script_pubkey: external_desc
                        .at_derivation_index(external_index)
-                        .unwrap()
                        .script_pubkey(),
-                    value: Amount::from_sat(10_000),
+                    value: 10_000,
                },
                TxOut {
                    script_pubkey: internal_desc
                        .at_derivation_index(internal_index)
-                        .unwrap()
                        .script_pubkey(),
-                    value: Amount::from_sat(10_000),
+                    value: 10_000,
                },
            ],
            ..common::new_tx(external_index)
        };
-        assert_eq!(txout_index.index_tx(&tx), keychain::ChangeSet::default());
+        assert_eq!(txout_index.scan(&tx), DerivationAdditions::default());
        assert_eq!(
            txout_index.last_revealed_index(&TestKeychain::External),
            Some(last_external_index)
@@ -199,13 +199,13 @@ fn test_lookahead() {
        );
        assert_eq!(
            txout_index
-                .revealed_keychain_spks(&TestKeychain::External)
+                .revealed_spks_of_keychain(&TestKeychain::External)
                .count(),
            last_external_index as usize + 1,
        );
        assert_eq!(
            txout_index
-                .revealed_keychain_spks(&TestKeychain::Internal)
+                .revealed_spks_of_keychain(&TestKeychain::Internal)
                .count(),
            last_internal_index as usize + 1,
        );
@@ -219,31 +219,24 @@ fn test_lookahead() {
 // - last used index should change as expected
 #[test]
 fn test_scan_with_lookahead() {
-    let (mut txout_index, external_desc, _) = init_txout_index(10);
+    let (mut txout_index, external_desc, _) = init_txout_index();
+    txout_index.set_lookahead_for_all(10);

-    let spks: BTreeMap<u32, ScriptBuf> = [0, 10, 20, 30]
+    let spks: BTreeMap<u32, Script> = [0, 10, 20, 30]
        .into_iter()
-        .map(|i| {
-            (
-                i,
-                external_desc
-                    .at_derivation_index(i)
-                    .unwrap()
-                    .script_pubkey(),
-            )
-        })
+        .map(|i| (i, external_desc.at_derivation_index(i).script_pubkey()))
        .collect();

    for (&spk_i, spk) in &spks {
        let op = OutPoint::new(h!("fake tx"), spk_i);
        let txout = TxOut {
            script_pubkey: spk.clone(),
-            value: Amount::ZERO,
+            value: 0,
        };

-        let changeset = txout_index.index_txout(op, &txout);
+        let additions = txout_index.scan_txout(op, &txout);
        assert_eq!(
-            changeset.as_inner(),
+            additions.as_inner(),
            &[(TestKeychain::External, spk_i)].into()
        );
        assert_eq!(
@@ -257,40 +250,36 @@ fn test_scan_with_lookahead() {
    }

    // now try with index 41 (lookahead surpassed), we expect that the txout to not be indexed
-    let spk_41 = external_desc
-        .at_derivation_index(41)
-        .unwrap()
-        .script_pubkey();
+    let spk_41 = external_desc.at_derivation_index(41).script_pubkey();
    let op = OutPoint::new(h!("fake tx"), 41);
    let txout = TxOut {
        script_pubkey: spk_41,
-        value: Amount::ZERO,
+        value: 0,
    };
-    let changeset = txout_index.index_txout(op, &txout);
-    assert!(changeset.is_empty());
+    let additions = txout_index.scan_txout(op, &txout);
+    assert!(additions.is_empty());
 }

 #[test]
-#[rustfmt::skip]
 fn test_wildcard_derivations() {
-    let (mut txout_index, external_desc, _) = init_txout_index(0);
-    let external_spk_0 = external_desc.at_derivation_index(0).unwrap().script_pubkey();
-    let external_spk_16 = external_desc.at_derivation_index(16).unwrap().script_pubkey();
-    let external_spk_26 = external_desc.at_derivation_index(26).unwrap().script_pubkey();
-    let external_spk_27 = external_desc.at_derivation_index(27).unwrap().script_pubkey();
+    let (mut txout_index, external_desc, _) = init_txout_index();
+    let external_spk_0 = external_desc.at_derivation_index(0).script_pubkey();
+    let external_spk_16 = external_desc.at_derivation_index(16).script_pubkey();
+    let external_spk_26 = external_desc.at_derivation_index(26).script_pubkey();
+    let external_spk_27 = external_desc.at_derivation_index(27).script_pubkey();

    // - nothing is derived
    // - unused list is also empty
    //
    // - next_derivation_index() == (0, true)
-    // - derive_new() == ((0, <spk>), keychain::ChangeSet)
-    // - next_unused() == ((0, <spk>), keychain::ChangeSet:is_empty())
+    // - derive_new() == ((0, <spk>), DerivationAdditions)
+    // - next_unused() == ((0, <spk>), DerivationAdditions:is_empty())
    assert_eq!(txout_index.next_index(&TestKeychain::External), (0, true));
    let (spk, changeset) = txout_index.reveal_next_spk(&TestKeychain::External);
-    assert_eq!(spk, (0_u32, external_spk_0.as_script()));
+    assert_eq!(spk, (0_u32, &external_spk_0));
    assert_eq!(changeset.as_inner(), &[(TestKeychain::External, 0)].into());
    let (spk, changeset) = txout_index.next_unused_spk(&TestKeychain::External);
-    assert_eq!(spk, (0_u32, external_spk_0.as_script()));
+    assert_eq!(spk, (0_u32, &external_spk_0));
    assert_eq!(changeset.as_inner(), &[].into());

    // - derived till 25
@@ -299,45 +288,45 @@ fn test_wildcard_derivations() {
    // - unused list: [16, 18, 19, 21, 22, 24, 25]

    // - next_derivation_index() = (26, true)
-    // - derive_new() = ((26, <spk>), keychain::ChangeSet)
-    // - next_unused() == ((16, <spk>), keychain::ChangeSet::is_empty())
+    // - derive_new() = ((26, <spk>), DerivationAdditions)
+    // - next_unused() == ((16, <spk>), DerivationAdditions::is_empty())
    let _ = txout_index.reveal_to_target(&TestKeychain::External, 25);

    (0..=15)
-        .chain([17, 20, 23])
-        .for_each(|index| assert!(txout_index.mark_used(TestKeychain::External, index)));
+        .into_iter()
+        .chain(vec![17, 20, 23].into_iter())
+        .for_each(|index| assert!(txout_index.mark_used(&TestKeychain::External, index)));

    assert_eq!(txout_index.next_index(&TestKeychain::External), (26, true));

    let (spk, changeset) = txout_index.reveal_next_spk(&TestKeychain::External);
-    assert_eq!(spk, (26, external_spk_26.as_script()));
+    assert_eq!(spk, (26, &external_spk_26));

    assert_eq!(changeset.as_inner(), &[(TestKeychain::External, 26)].into());

    let (spk, changeset) = txout_index.next_unused_spk(&TestKeychain::External);
-    assert_eq!(spk, (16, external_spk_16.as_script()));
+    assert_eq!(spk, (16, &external_spk_16));
    assert_eq!(changeset.as_inner(), &[].into());

    // - Use all the derived till 26.
-    // - next_unused() = ((27, <spk>), keychain::ChangeSet)
-    (0..=26).for_each(|index| {
-        txout_index.mark_used(TestKeychain::External, index);
+    // - next_unused() = ((27, <spk>), DerivationAdditions)
+    (0..=26).into_iter().for_each(|index| {
+        txout_index.mark_used(&TestKeychain::External, index);
    });

    let (spk, changeset) = txout_index.next_unused_spk(&TestKeychain::External);
-    assert_eq!(spk, (27, external_spk_27.as_script()));
+    assert_eq!(spk, (27, &external_spk_27));
    assert_eq!(changeset.as_inner(), &[(TestKeychain::External, 27)].into());
 }

 #[test]
 fn test_non_wildcard_derivations() {
-    let mut txout_index = KeychainTxOutIndex::<TestKeychain>::new(0);
+    let mut txout_index = KeychainTxOutIndex::<TestKeychain>::default();

    let secp = bitcoin::secp256k1::Secp256k1::signing_only();
    let (no_wildcard_descriptor, _) = Descriptor::<DescriptorPublicKey>::parse_descriptor(&secp, "wpkh([73c5da0a/86'/0'/0']xprv9xgqHN7yz9MwCkxsBPN5qetuNdQSUttZNKw1dcYTV4mkaAFiBVGQziHs3NRSWMkCzvgjEe3n9xV8oYywvM8at9yRqyaZVz6TYYhX98VjsUk/1/0)").unwrap();
    let external_spk = no_wildcard_descriptor
        .at_derivation_index(0)
-        .unwrap()
        .script_pubkey();

    txout_index.add_keychain(TestKeychain::External, no_wildcard_descriptor);
@@ -350,11 +339,11 @@ fn test_non_wildcard_derivations() {
    // - when we get the next unused script, script @ index 0
    assert_eq!(txout_index.next_index(&TestKeychain::External), (0, true));
    let (spk, changeset) = txout_index.reveal_next_spk(&TestKeychain::External);
-    assert_eq!(spk, (0, external_spk.as_script()));
+    assert_eq!(spk, (0, &external_spk));
    assert_eq!(changeset.as_inner(), &[(TestKeychain::External, 0)].into());

    let (spk, changeset) = txout_index.next_unused_spk(&TestKeychain::External);
-    assert_eq!(spk, (0, external_spk.as_script()));
+    assert_eq!(spk, (0, &external_spk));
    assert_eq!(changeset.as_inner(), &[].into());

    // given:
@@ -362,127 +351,19 @@ fn test_non_wildcard_derivations() {
    // expect:
    // - next derivation index should not be new
    // - derive new and next unused should return the old script
-    // - store_up_to should not panic and return empty changeset
+    // - store_up_to should not panic and return empty additions
    assert_eq!(txout_index.next_index(&TestKeychain::External), (0, false));
-    txout_index.mark_used(TestKeychain::External, 0);
+    txout_index.mark_used(&TestKeychain::External, 0);

    let (spk, changeset) = txout_index.reveal_next_spk(&TestKeychain::External);
-    assert_eq!(spk, (0, external_spk.as_script()));
+    assert_eq!(spk, (0, &external_spk));
    assert_eq!(changeset.as_inner(), &[].into());

    let (spk, changeset) = txout_index.next_unused_spk(&TestKeychain::External);
-    assert_eq!(spk, (0, external_spk.as_script()));
+    assert_eq!(spk, (0, &external_spk));
    assert_eq!(changeset.as_inner(), &[].into());
-    let (revealed_spks, revealed_changeset) =
+    let (revealed_spks, revealed_additions) =
        txout_index.reveal_to_target(&TestKeychain::External, 200);
    assert_eq!(revealed_spks.count(), 0);
-    assert!(revealed_changeset.is_empty());
-
-    // we check that spks_of_keychain returns a SpkIterator with just one element
-    assert_eq!(
-        txout_index
-            .revealed_keychain_spks(&TestKeychain::External)
-            .count(),
-        1,
-    );
-}
-
-/// Check that calling `lookahead_to_target` stores the expected spks.
-#[test]
-fn lookahead_to_target() {
-    #[derive(Default)]
-    struct TestCase {
-        /// Global lookahead value.
-        lookahead: u32,
-        /// Last revealed index for external keychain.
-        external_last_revealed: Option<u32>,
-        /// Last revealed index for internal keychain.
-        internal_last_revealed: Option<u32>,
-        /// Call `lookahead_to_target(External, u32)`.
-        external_target: Option<u32>,
-        /// Call `lookahead_to_target(Internal, u32)`.
-        internal_target: Option<u32>,
-    }
-
-    let test_cases = &[
-        TestCase {
-            lookahead: 0,
-            external_target: Some(100),
-            ..Default::default()
-        },
-        TestCase {
-            lookahead: 10,
-            internal_target: Some(99),
-            ..Default::default()
-        },
-        TestCase {
-            lookahead: 100,
-            internal_target: Some(9),
-            external_target: Some(10),
-            ..Default::default()
-        },
-        TestCase {
-            lookahead: 12,
-            external_last_revealed: Some(2),
-            internal_last_revealed: Some(2),
-            internal_target: Some(15),
-            external_target: Some(13),
-        },
-        TestCase {
-            lookahead: 13,
-            external_last_revealed: Some(100),
-            internal_last_revealed: Some(21),
-            internal_target: Some(120),
-            external_target: Some(130),
-        },
-    ];
-
-    for t in test_cases {
-        let (mut index, _, _) = init_txout_index(t.lookahead);
-
-        if let Some(last_revealed) = t.external_last_revealed {
-            let _ = index.reveal_to_target(&TestKeychain::External, last_revealed);
-        }
-        if let Some(last_revealed) = t.internal_last_revealed {
-            let _ = index.reveal_to_target(&TestKeychain::Internal, last_revealed);
-        }
-
-        let keychain_test_cases = [
-            (
-                TestKeychain::External,
-                t.external_last_revealed,
-                t.external_target,
-            ),
-            (
-                TestKeychain::Internal,
-                t.internal_last_revealed,
-                t.internal_target,
-            ),
-        ];
-        for (keychain, last_revealed, target) in keychain_test_cases {
-            if let Some(target) = target {
-                let original_last_stored_index = match last_revealed {
-                    Some(last_revealed) => Some(last_revealed + t.lookahead),
-                    None => t.lookahead.checked_sub(1),
-                };
-                let exp_last_stored_index = match original_last_stored_index {
-                    Some(original_last_stored_index) => {
-                        Ord::max(target, original_last_stored_index)
-                    }
-                    None => target,
-                };
-                index.lookahead_to_target(&keychain, target);
-                let keys = index
-                    .inner()
-                    .all_spks()
-                    .range((keychain.clone(), 0)..=(keychain.clone(), u32::MAX))
-                    .map(|(k, _)| k.clone())
-                    .collect::<Vec<_>>();
-                let exp_keys = core::iter::repeat(keychain)
-                    .zip(0_u32..=exp_last_stored_index)
-                    .collect::<Vec<_>>();
-                assert_eq!(keys, exp_keys);
-            }
-        }
-    }
+    assert!(revealed_additions.is_empty());
 }
--- a/crates/chain/tests/test_local_chain.rs
+++ b/crates/chain/tests/test_local_chain.rs
@@ -1,775 +0,0 @@
-use std::ops::{Bound, RangeBounds};
-
-use bdk_chain::{
-    local_chain::{
-        AlterCheckPointError, ApplyHeaderError, CannotConnectError, ChangeSet, CheckPoint,
-        LocalChain, MissingGenesisError, Update,
-    },
-    BlockId,
-};
-use bitcoin::{block::Header, hashes::Hash, BlockHash};
-use proptest::prelude::*;
-
-#[macro_use]
-mod common;
-
-#[derive(Debug)]
-struct TestLocalChain<'a> {
-    name: &'static str,
-    chain: LocalChain,
-    update: Update,
-    exp: ExpectedResult<'a>,
-}
-
-#[derive(Debug, PartialEq)]
-enum ExpectedResult<'a> {
-    Ok {
-        changeset: &'a [(u32, Option<BlockHash>)],
-        init_changeset: &'a [(u32, Option<BlockHash>)],
-    },
-    Err(CannotConnectError),
-}
-
-impl<'a> TestLocalChain<'a> {
-    fn run(mut self) {
-        println!("[TestLocalChain] test: {}", self.name);
-        let got_changeset = match self.chain.apply_update(self.update) {
-            Ok(changeset) => changeset,
-            Err(got_err) => {
-                assert_eq!(
-                    ExpectedResult::Err(got_err),
-                    self.exp,
-                    "{}: unexpected error",
-                    self.name
-                );
-                return;
-            }
-        };
-
-        match self.exp {
-            ExpectedResult::Ok {
-                changeset,
-                init_changeset,
-            } => {
-                assert_eq!(
-                    got_changeset,
-                    changeset.iter().cloned().collect(),
-                    "{}: unexpected changeset",
-                    self.name
-                );
-                assert_eq!(
-                    self.chain.initial_changeset(),
-                    init_changeset.iter().cloned().collect(),
-                    "{}: unexpected initial changeset",
-                    self.name
-                );
-            }
-            ExpectedResult::Err(err) => panic!(
-                "{}: expected error ({}), got non-error result: {:?}",
-                self.name, err, got_changeset
-            ),
-        }
-    }
-}
-
-#[test]
-fn update_local_chain() {
-    [
-        TestLocalChain {
-            name: "add first tip",
-            chain: local_chain![(0, h!("A"))],
-            update: chain_update![(0, h!("A"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[],
-                init_changeset: &[(0, Some(h!("A")))],
-            },
-        },
-        TestLocalChain {
-            name: "add second tip",
-            chain: local_chain![(0, h!("A"))],
-            update: chain_update![(0, h!("A")), (1, h!("B"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[(1, Some(h!("B")))],
-                init_changeset: &[(0, Some(h!("A"))), (1, Some(h!("B")))],
-            },
-        },
-        TestLocalChain {
-            name: "two disjoint chains cannot merge",
-            chain: local_chain![(0, h!("_")), (1, h!("A"))],
-            update: chain_update![(0, h!("_")), (2, h!("B"))],
-            exp: ExpectedResult::Err(CannotConnectError {
-                try_include_height: 1,
-            }),
-        },
-        TestLocalChain {
-            name: "two disjoint chains cannot merge (existing chain longer)",
-            chain: local_chain![(0, h!("_")), (2, h!("A"))],
-            update: chain_update![(0, h!("_")), (1, h!("B"))],
-            exp: ExpectedResult::Err(CannotConnectError {
-                try_include_height: 2,
-            }),
-        },
-        TestLocalChain {
-            name: "duplicate chains should merge",
-            chain: local_chain![(0, h!("A"))],
-            update: chain_update![(0, h!("A"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[],
-                init_changeset: &[(0, Some(h!("A")))],
-            },
-        },
-        // Introduce an older checkpoint (B)
-        //        | 0 | 1 | 2 | 3
-        // chain  | _       C   D
-        // update | _   B   C
-        TestLocalChain {
-            name: "can introduce older checkpoint",
-            chain: local_chain![(0, h!("_")), (2, h!("C")), (3, h!("D"))],
-            update: chain_update![(0, h!("_")), (1, h!("B")), (2, h!("C"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[(1, Some(h!("B")))],
-                init_changeset: &[(0, Some(h!("_"))), (1, Some(h!("B"))), (2, Some(h!("C"))), (3, Some(h!("D")))],
-            },
-        },
-        // Introduce an older checkpoint (A) that is not directly behind PoA
-        //        | 0 | 2 | 3 | 4
-        // chain  | _       B   C
-        // update | _   A       C
-        TestLocalChain {
-            name: "can introduce older checkpoint 2",
-            chain: local_chain![(0, h!("_")), (3, h!("B")), (4, h!("C"))],
-            update: chain_update![(0, h!("_")), (2, h!("A")), (4, h!("C"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[(2, Some(h!("A")))],
-                init_changeset: &[(0, Some(h!("_"))), (2, Some(h!("A"))), (3, Some(h!("B"))), (4, Some(h!("C")))],
-            }
-        },
-        // Introduce an older checkpoint (B) that is not the oldest checkpoint
-        //        | 0 | 1 | 2 | 3
-        // chain  | _   A       C
-        // update | _       B   C
-        TestLocalChain {
-            name: "can introduce older checkpoint 3",
-            chain: local_chain![(0, h!("_")), (1, h!("A")), (3, h!("C"))],
-            update: chain_update![(0, h!("_")), (2, h!("B")), (3, h!("C"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[(2, Some(h!("B")))],
-                init_changeset: &[(0, Some(h!("_"))), (1, Some(h!("A"))), (2, Some(h!("B"))), (3, Some(h!("C")))],
-            }
-        },
-        // Introduce two older checkpoints below the PoA
-        //        | 0 | 1 | 2 | 3
-        // chain  | _           C
-        // update | _   A   B   C
-        TestLocalChain {
-            name: "introduce two older checkpoints below PoA",
-            chain: local_chain![(0, h!("_")), (3, h!("C"))],
-            update: chain_update![(0, h!("_")), (1, h!("A")), (2, h!("B")), (3, h!("C"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[(1, Some(h!("A"))), (2, Some(h!("B")))],
-                init_changeset: &[(0, Some(h!("_"))), (1, Some(h!("A"))), (2, Some(h!("B"))), (3, Some(h!("C")))],
-            },
-        },
-        TestLocalChain {
-            name: "fix blockhash before agreement point",
-            chain: local_chain![(0, h!("im-wrong")), (1, h!("we-agree"))],
-            update: chain_update![(0, h!("fix")), (1, h!("we-agree"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[(0, Some(h!("fix")))],
-                init_changeset: &[(0, Some(h!("fix"))), (1, Some(h!("we-agree")))],
-            },
-        },
-        // B and C are in both chain and update
-        //        | 0 | 1 | 2 | 3 | 4
-        // chain  | _       B   C
-        // update | _   A   B   C   D
-        // This should succeed with the point of agreement being C and A should be added in addition.
-        TestLocalChain {
-            name: "two points of agreement",
-            chain: local_chain![(0, h!("_")), (2, h!("B")), (3, h!("C"))],
-            update: chain_update![(0, h!("_")), (1, h!("A")), (2, h!("B")), (3, h!("C")), (4, h!("D"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[(1, Some(h!("A"))), (4, Some(h!("D")))],
-                init_changeset: &[
-                    (0, Some(h!("_"))),
-                    (1, Some(h!("A"))),
-                    (2, Some(h!("B"))),
-                    (3, Some(h!("C"))),
-                    (4, Some(h!("D"))),
-                ],
-            },
-        },
-        // Update and chain does not connect:
-        //        | 0 | 1 | 2 | 3 | 4
-        // chain  | _       B   C
-        // update | _   A   B       D
-        // This should fail as we cannot figure out whether C & D are on the same chain
-        TestLocalChain {
-            name: "update and chain does not connect",
-            chain: local_chain![(0, h!("_")), (2, h!("B")), (3, h!("C"))],
-            update: chain_update![(0, h!("_")), (1, h!("A")), (2, h!("B")), (4, h!("D"))],
-            exp: ExpectedResult::Err(CannotConnectError {
-                try_include_height: 3,
-            }),
-        },
-        // Transient invalidation:
-        //        | 0 | 1 | 2 | 3 | 4 | 5
-        // chain  | _       B   C       E
-        // update | _       B'  C'  D
-        // This should succeed and invalidate B,C and E with point of agreement being A.
-        TestLocalChain {
-            name: "transitive invalidation applies to checkpoints higher than invalidation",
-            chain: local_chain![(0, h!("_")), (2, h!("B")), (3, h!("C")), (5, h!("E"))],
-            update: chain_update![(0, h!("_")), (2, h!("B'")), (3, h!("C'")), (4, h!("D"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[
-                    (2, Some(h!("B'"))),
-                    (3, Some(h!("C'"))),
-                    (4, Some(h!("D"))),
-                    (5, None),
-                ],
-                init_changeset: &[
-                    (0, Some(h!("_"))),
-                    (2, Some(h!("B'"))),
-                    (3, Some(h!("C'"))),
-                    (4, Some(h!("D"))),
-                ],
-            },
-        },
-        // Transient invalidation:
-        //        | 0 | 1 | 2 | 3 | 4
-        // chain  | _   B   C       E
-        // update | _   B'  C'  D
-        // This should succeed and invalidate B, C and E with no point of agreement
-        TestLocalChain {
-            name: "transitive invalidation applies to checkpoints higher than invalidation no point of agreement",
-            chain: local_chain![(0, h!("_")), (1, h!("B")), (2, h!("C")), (4, h!("E"))],
-            update: chain_update![(0, h!("_")), (1, h!("B'")), (2, h!("C'")), (3, h!("D"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[
-                    (1, Some(h!("B'"))),
-                    (2, Some(h!("C'"))),
-                    (3, Some(h!("D"))),
-                    (4, None)
-                ],
-                init_changeset: &[
-                    (0, Some(h!("_"))), 
-                    (1, Some(h!("B'"))),
-                    (2, Some(h!("C'"))),
-                    (3, Some(h!("D"))),
-                ],
-            },
-        },
-        // Transient invalidation:
-        //        | 0 | 1 | 2 | 3 | 4 | 5
-        // chain  | _   A   B   C       E
-        // update | _       B'  C'  D
-        // This should fail since although it tells us that B and C are invalid it doesn't tell us whether
-        // A was invalid.
-        TestLocalChain {
-            name: "invalidation but no connection",
-            chain: local_chain![(0, h!("_")), (1, h!("A")), (2, h!("B")), (3, h!("C")), (5, h!("E"))],
-            update: chain_update![(0, h!("_")), (2, h!("B'")), (3, h!("C'")), (4, h!("D"))],
-            exp: ExpectedResult::Err(CannotConnectError { try_include_height: 1 }),
-        },
-        // Introduce blocks between two points of agreement
-        //        | 0 | 1 | 2 | 3 | 4 | 5
-        // chain  | A   B       D   E
-        // update | A       C       E   F
-        TestLocalChain {
-            name: "introduce blocks between two points of agreement",
-            chain: local_chain![(0, h!("A")), (1, h!("B")), (3, h!("D")), (4, h!("E"))],
-            update: chain_update![(0, h!("A")), (2, h!("C")), (4, h!("E")), (5, h!("F"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[
-                    (2, Some(h!("C"))),
-                    (5, Some(h!("F"))),
-                ],
-                init_changeset: &[
-                    (0, Some(h!("A"))),
-                    (1, Some(h!("B"))),
-                    (2, Some(h!("C"))),
-                    (3, Some(h!("D"))),
-                    (4, Some(h!("E"))),
-                    (5, Some(h!("F"))),
-                ],
-            },
-        },
-        // Allow update that is shorter than original chain
-        //        | 0 | 1 | 2 | 3 | 4 | 5
-        // chain  | A       C   D   E   F
-        // update | A       C   D'
-        TestLocalChain {
-            name: "allow update that is shorter than original chain",
-            chain: local_chain![(0, h!("_")), (2, h!("C")), (3, h!("D")), (4, h!("E")), (5, h!("F"))],
-            update: chain_update![(0, h!("_")), (2, h!("C")), (3, h!("D'"))],
-            exp: ExpectedResult::Ok {
-                changeset: &[
-                    (3, Some(h!("D'"))),
-                    (4, None),
-                    (5, None),
-                ],
-                init_changeset: &[
-                    (0, Some(h!("_"))),
-                    (2, Some(h!("C"))),
-                    (3, Some(h!("D'"))),
-                ],
-            },
-        },
-    ]
-    .into_iter()
-    .for_each(TestLocalChain::run);
-}
-
-#[test]
-fn local_chain_insert_block() {
-    struct TestCase {
-        original: LocalChain,
-        insert: (u32, BlockHash),
-        expected_result: Result<ChangeSet, AlterCheckPointError>,
-        expected_final: LocalChain,
-    }
-
-    let test_cases = [
-        TestCase {
-            original: local_chain![(0, h!("_"))],
-            insert: (5, h!("block5")),
-            expected_result: Ok([(5, Some(h!("block5")))].into()),
-            expected_final: local_chain![(0, h!("_")), (5, h!("block5"))],
-        },
-        TestCase {
-            original: local_chain![(0, h!("_")), (3, h!("A"))],
-            insert: (4, h!("B")),
-            expected_result: Ok([(4, Some(h!("B")))].into()),
-            expected_final: local_chain![(0, h!("_")), (3, h!("A")), (4, h!("B"))],
-        },
-        TestCase {
-            original: local_chain![(0, h!("_")), (4, h!("B"))],
-            insert: (3, h!("A")),
-            expected_result: Ok([(3, Some(h!("A")))].into()),
-            expected_final: local_chain![(0, h!("_")), (3, h!("A")), (4, h!("B"))],
-        },
-        TestCase {
-            original: local_chain![(0, h!("_")), (2, h!("K"))],
-            insert: (2, h!("K")),
-            expected_result: Ok([].into()),
-            expected_final: local_chain![(0, h!("_")), (2, h!("K"))],
-        },
-        TestCase {
-            original: local_chain![(0, h!("_")), (2, h!("K"))],
-            insert: (2, h!("J")),
-            expected_result: Err(AlterCheckPointError {
-                height: 2,
-                original_hash: h!("K"),
-                update_hash: Some(h!("J")),
-            }),
-            expected_final: local_chain![(0, h!("_")), (2, h!("K"))],
-        },
-    ];
-
-    for (i, t) in test_cases.into_iter().enumerate() {
-        let mut chain = t.original;
-        assert_eq!(
-            chain.insert_block(t.insert.into()),
-            t.expected_result,
-            "[{}] unexpected result when inserting block",
-            i,
-        );
-        assert_eq!(chain, t.expected_final, "[{}] unexpected final chain", i,);
-    }
-}
-
-#[test]
-fn local_chain_disconnect_from() {
-    struct TestCase {
-        name: &'static str,
-        original: LocalChain,
-        disconnect_from: (u32, BlockHash),
-        exp_result: Result<ChangeSet, MissingGenesisError>,
-        exp_final: LocalChain,
-    }
-
-    let test_cases = [
-        TestCase {
-            name: "try_replace_genesis_should_fail",
-            original: local_chain![(0, h!("_"))],
-            disconnect_from: (0, h!("_")),
-            exp_result: Err(MissingGenesisError),
-            exp_final: local_chain![(0, h!("_"))],
-        },
-        TestCase {
-            name: "try_replace_genesis_should_fail_2",
-            original: local_chain![(0, h!("_")), (2, h!("B")), (3, h!("C"))],
-            disconnect_from: (0, h!("_")),
-            exp_result: Err(MissingGenesisError),
-            exp_final: local_chain![(0, h!("_")), (2, h!("B")), (3, h!("C"))],
-        },
-        TestCase {
-            name: "from_does_not_exist",
-            original: local_chain![(0, h!("_")), (3, h!("C"))],
-            disconnect_from: (2, h!("B")),
-            exp_result: Ok(ChangeSet::default()),
-            exp_final: local_chain![(0, h!("_")), (3, h!("C"))],
-        },
-        TestCase {
-            name: "from_has_different_blockhash",
-            original: local_chain![(0, h!("_")), (2, h!("B"))],
-            disconnect_from: (2, h!("not_B")),
-            exp_result: Ok(ChangeSet::default()),
-            exp_final: local_chain![(0, h!("_")), (2, h!("B"))],
-        },
-        TestCase {
-            name: "disconnect_one",
-            original: local_chain![(0, h!("_")), (2, h!("B"))],
-            disconnect_from: (2, h!("B")),
-            exp_result: Ok(ChangeSet::from_iter([(2, None)])),
-            exp_final: local_chain![(0, h!("_"))],
-        },
-        TestCase {
-            name: "disconnect_three",
-            original: local_chain![(0, h!("_")), (2, h!("B")), (3, h!("C")), (4, h!("D"))],
-            disconnect_from: (2, h!("B")),
-            exp_result: Ok(ChangeSet::from_iter([(2, None), (3, None), (4, None)])),
-            exp_final: local_chain![(0, h!("_"))],
-        },
-    ];
-
-    for (i, t) in test_cases.into_iter().enumerate() {
-        println!("Case {}: {}", i, t.name);
-
-        let mut chain = t.original;
-        let result = chain.disconnect_from(t.disconnect_from.into());
-        assert_eq!(
-            result, t.exp_result,
-            "[{}:{}] unexpected changeset result",
-            i, t.name
-        );
-        assert_eq!(
-            chain, t.exp_final,
-            "[{}:{}] unexpected final chain",
-            i, t.name
-        );
-    }
-}
-
-#[test]
-fn checkpoint_from_block_ids() {
-    struct TestCase<'a> {
-        name: &'a str,
-        blocks: &'a [(u32, BlockHash)],
-        exp_result: Result<(), Option<(u32, BlockHash)>>,
-    }
-
-    let test_cases = [
-        TestCase {
-            name: "in_order",
-            blocks: &[(0, h!("A")), (1, h!("B")), (3, h!("D"))],
-            exp_result: Ok(()),
-        },
-        TestCase {
-            name: "with_duplicates",
-            blocks: &[(1, h!("B")), (2, h!("C")), (2, h!("C'"))],
-            exp_result: Err(Some((2, h!("C")))),
-        },
-        TestCase {
-            name: "not_in_order",
-            blocks: &[(1, h!("B")), (3, h!("D")), (2, h!("C"))],
-            exp_result: Err(Some((3, h!("D")))),
-        },
-        TestCase {
-            name: "empty",
-            blocks: &[],
-            exp_result: Err(None),
-        },
-        TestCase {
-            name: "single",
-            blocks: &[(21, h!("million"))],
-            exp_result: Ok(()),
-        },
-    ];
-
-    for (i, t) in test_cases.into_iter().enumerate() {
-        println!("running test case {}: '{}'", i, t.name);
-        let result = CheckPoint::from_block_ids(
-            t.blocks
-                .iter()
-                .map(|&(height, hash)| BlockId { height, hash }),
-        );
-        match t.exp_result {
-            Ok(_) => {
-                assert!(result.is_ok(), "[{}:{}] should be Ok", i, t.name);
-                let result_vec = {
-                    let mut v = result
-                        .unwrap()
-                        .into_iter()
-                        .map(|cp| (cp.height(), cp.hash()))
-                        .collect::<Vec<_>>();
-                    v.reverse();
-                    v
-                };
-                assert_eq!(
-                    &result_vec, t.blocks,
-                    "[{}:{}] not equal to original block ids",
-                    i, t.name
-                );
-            }
-            Err(exp_last) => {
-                assert!(result.is_err(), "[{}:{}] should be Err", i, t.name);
-                let err = result.unwrap_err();
-                assert_eq!(
-                    err.as_ref()
-                        .map(|last_cp| (last_cp.height(), last_cp.hash())),
-                    exp_last,
-                    "[{}:{}] error's last cp height should be {:?}, got {:?}",
-                    i,
-                    t.name,
-                    exp_last,
-                    err
-                );
-            }
-        }
-    }
-}
-
-#[test]
-fn checkpoint_query() {
-    struct TestCase {
-        chain: LocalChain,
-        /// The heights we want to call [`CheckPoint::query`] with, represented as an inclusive
-        /// range.
-        ///
-        /// If a [`CheckPoint`] exists at that height, we expect [`CheckPoint::query`] to return
-        /// it. If not, [`CheckPoint::query`] should return `None`.
-        query_range: (u32, u32),
-    }
-
-    let test_cases = [
-        TestCase {
-            chain: local_chain![(0, h!("_")), (1, h!("A"))],
-            query_range: (0, 2),
-        },
-        TestCase {
-            chain: local_chain![(0, h!("_")), (2, h!("B")), (3, h!("C"))],
-            query_range: (0, 3),
-        },
-    ];
-
-    for t in test_cases.into_iter() {
-        let tip = t.chain.tip();
-        for h in t.query_range.0..=t.query_range.1 {
-            let query_result = tip.get(h);
-
-            // perform an exhausitive search for the checkpoint at height `h`
-            let exp_hash = t
-                .chain
-                .iter_checkpoints()
-                .find(|cp| cp.height() == h)
-                .map(|cp| cp.hash());
-
-            match query_result {
-                Some(cp) => {
-                    assert_eq!(Some(cp.hash()), exp_hash);
-                    assert_eq!(cp.height(), h);
-                }
-                None => assert!(exp_hash.is_none()),
-            }
-        }
-    }
-}
-
-#[test]
-fn local_chain_apply_header_connected_to() {
-    fn header_from_prev_blockhash(prev_blockhash: BlockHash) -> Header {
-        Header {
-            version: bitcoin::block::Version::default(),
-            prev_blockhash,
-            merkle_root: bitcoin::hash_types::TxMerkleNode::all_zeros(),
-            time: 0,
-            bits: bitcoin::CompactTarget::default(),
-            nonce: 0,
-        }
-    }
-
-    struct TestCase {
-        name: &'static str,
-        chain: LocalChain,
-        header: Header,
-        height: u32,
-        connected_to: BlockId,
-        exp_result: Result<Vec<(u32, Option<BlockHash>)>, ApplyHeaderError>,
-    }
-
-    let test_cases = [
-        {
-            let header = header_from_prev_blockhash(h!("A"));
-            let hash = header.block_hash();
-            let height = 2;
-            let connected_to = BlockId { height, hash };
-            TestCase {
-                name: "connected_to_self_header_applied_to_self",
-                chain: local_chain![(0, h!("_")), (height, hash)],
-                header,
-                height,
-                connected_to,
-                exp_result: Ok(vec![]),
-            }
-        },
-        {
-            let prev_hash = h!("A");
-            let prev_height = 1;
-            let header = header_from_prev_blockhash(prev_hash);
-            let hash = header.block_hash();
-            let height = prev_height + 1;
-            let connected_to = BlockId {
-                height: prev_height,
-                hash: prev_hash,
-            };
-            TestCase {
-                name: "connected_to_prev_header_applied_to_self",
-                chain: local_chain![(0, h!("_")), (prev_height, prev_hash)],
-                header,
-                height,
-                connected_to,
-                exp_result: Ok(vec![(height, Some(hash))]),
-            }
-        },
-        {
-            let header = header_from_prev_blockhash(BlockHash::all_zeros());
-            let hash = header.block_hash();
-            let height = 0;
-            let connected_to = BlockId { height, hash };
-            TestCase {
-                name: "genesis_applied_to_self",
-                chain: local_chain![(0, hash)],
-                header,
-                height,
-                connected_to,
-                exp_result: Ok(vec![]),
-            }
-        },
-        {
-            let header = header_from_prev_blockhash(h!("Z"));
-            let height = 10;
-            let hash = header.block_hash();
-            let prev_height = height - 1;
-            let prev_hash = header.prev_blockhash;
-            TestCase {
-                name: "connect_at_connected_to",
-                chain: local_chain![(0, h!("_")), (2, h!("B")), (3, h!("C"))],
-                header,
-                height: 10,
-                connected_to: BlockId {
-                    height: 3,
-                    hash: h!("C"),
-                },
-                exp_result: Ok(vec![(prev_height, Some(prev_hash)), (height, Some(hash))]),
-            }
-        },
-        {
-            let prev_hash = h!("A");
-            let prev_height = 1;
-            let header = header_from_prev_blockhash(prev_hash);
-            let connected_to = BlockId {
-                height: prev_height,
-                hash: h!("not_prev_hash"),
-            };
-            TestCase {
-                name: "inconsistent_prev_hash",
-                chain: local_chain![(0, h!("_")), (prev_height, h!("not_prev_hash"))],
-                header,
-                height: prev_height + 1,
-                connected_to,
-                exp_result: Err(ApplyHeaderError::InconsistentBlocks),
-            }
-        },
-        {
-            let prev_hash = h!("A");
-            let prev_height = 1;
-            let header = header_from_prev_blockhash(prev_hash);
-            let height = prev_height + 1;
-            let connected_to = BlockId {
-                height,
-                hash: h!("not_current_hash"),
-            };
-            TestCase {
-                name: "inconsistent_current_block",
-                chain: local_chain![(0, h!("_")), (height, h!("not_current_hash"))],
-                header,
-                height,
-                connected_to,
-                exp_result: Err(ApplyHeaderError::InconsistentBlocks),
-            }
-        },
-        {
-            let header = header_from_prev_blockhash(h!("B"));
-            let height = 3;
-            let connected_to = BlockId {
-                height: 4,
-                hash: h!("D"),
-            };
-            TestCase {
-                name: "connected_to_is_greater",
-                chain: local_chain![(0, h!("_")), (2, h!("B"))],
-                header,
-                height,
-                connected_to,
-                exp_result: Err(ApplyHeaderError::InconsistentBlocks),
-            }
-        },
-    ];
-
-    for (i, t) in test_cases.into_iter().enumerate() {
-        println!("running test case {}: '{}'", i, t.name);
-        let mut chain = t.chain;
-        let result = chain.apply_header_connected_to(&t.header, t.height, t.connected_to);
-        let exp_result = t
-            .exp_result
-            .map(|cs| cs.iter().cloned().collect::<ChangeSet>());
-        assert_eq!(result, exp_result, "[{}:{}] unexpected result", i, t.name);
-    }
-}
-
-fn generate_height_range_bounds(
-    height_upper_bound: u32,
-) -> impl Strategy<Value = (Bound<u32>, Bound<u32>)> {
-    fn generate_height_bound(height_upper_bound: u32) -> impl Strategy<Value = Bound<u32>> {
-        prop_oneof![
-            (0..height_upper_bound).prop_map(Bound::Included),
-            (0..height_upper_bound).prop_map(Bound::Excluded),
-            Just(Bound::Unbounded),
-        ]
-    }
-    (
-        generate_height_bound(height_upper_bound),
-        generate_height_bound(height_upper_bound),
-    )
-}
-
-fn generate_checkpoints(max_height: u32, max_count: usize) -> impl Strategy<Value = CheckPoint> {
-    proptest::collection::btree_set(1..max_height, 0..max_count).prop_map(|mut heights| {
-        heights.insert(0); // must have genesis
-        CheckPoint::from_block_ids(heights.into_iter().map(|height| {
-            let hash = bitcoin::hashes::Hash::hash(height.to_le_bytes().as_slice());
-            BlockId { height, hash }
-        }))
-        .expect("blocks must be in order as it comes from btreeset")
-    })
-}
-
-proptest! {
-    #![proptest_config(ProptestConfig {
-        ..Default::default()
-    })]
-
-    /// Ensure that [`CheckPoint::range`] returns the expected checkpoint heights by comparing it
-    /// against a more primitive approach.
-    #[test]
-    fn checkpoint_range(
-        range in generate_height_range_bounds(21_000),
-        cp in generate_checkpoints(21_000, 2100)
-    ) {
-        let exp_heights = cp.iter().map(|cp| cp.height()).filter(|h| range.contains(h)).collect::<Vec<u32>>();
-        let heights = cp.range(range).map(|cp| cp.height()).collect::<Vec<u32>>();
-        prop_assert_eq!(heights, exp_heights);
-    }
-}
--- a/crates/chain/tests/test_sparse_chain.rs
+++ b/crates/chain/tests/test_sparse_chain.rs
@@ -0,0 +1,773 @@
+#[macro_use]
+mod common;
+
+use bdk_chain::{collections::BTreeSet, sparse_chain::*, BlockId, TxHeight};
+use bitcoin::{hashes::Hash, Txid};
+use core::ops::Bound;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd, Hash)]
+pub struct TestIndex(TxHeight, u32);
+
+impl ChainPosition for TestIndex {
+    fn height(&self) -> TxHeight {
+        self.0
+    }
+
+    fn max_ord_of_height(height: TxHeight) -> Self {
+        Self(height, u32::MAX)
+    }
+
+    fn min_ord_of_height(height: TxHeight) -> Self {
+        Self(height, u32::MIN)
+    }
+}
+
+impl TestIndex {
+    pub fn new<H>(height: H, ext: u32) -> Self
+    where
+        H: Into<TxHeight>,
+    {
+        Self(height.into(), ext)
+    }
+}
+
+#[test]
+fn add_first_checkpoint() {
+    let chain = SparseChain::default();
+    assert_eq!(
+        chain.determine_changeset(&chain!([0, h!("A")])),
+        Ok(changeset! {
+            checkpoints: [(0, Some(h!("A")))],
+            txids: []
+        },),
+        "add first tip"
+    );
+}
+
+#[test]
+fn add_second_tip() {
+    let chain = chain!([0, h!("A")]);
+    assert_eq!(
+        chain.determine_changeset(&chain!([0, h!("A")], [1, h!("B")])),
+        Ok(changeset! {
+            checkpoints: [(1, Some(h!("B")))],
+            txids: []
+        },),
+        "extend tip by one"
+    );
+}
+
+#[test]
+fn two_disjoint_chains_cannot_merge() {
+    let chain1 = chain!([0, h!("A")]);
+    let chain2 = chain!([1, h!("B")]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Err(UpdateError::NotConnected(0))
+    );
+}
+
+#[test]
+fn duplicate_chains_should_merge() {
+    let chain1 = chain!([0, h!("A")]);
+    let chain2 = chain!([0, h!("A")]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(ChangeSet::default())
+    );
+}
+
+#[test]
+fn duplicate_chains_with_txs_should_merge() {
+    let chain1 = chain!(checkpoints: [[0,h!("A")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    let chain2 = chain!(checkpoints: [[0,h!("A")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(ChangeSet::default())
+    );
+}
+
+#[test]
+fn duplicate_chains_with_different_txs_should_merge() {
+    let chain1 = chain!(checkpoints: [[0,h!("A")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    let chain2 = chain!(checkpoints: [[0,h!("A")]], txids: [(h!("tx1"), TxHeight::Confirmed(0))]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [],
+            txids: [(h!("tx1"), Some(TxHeight::Confirmed(0)))]
+        })
+    );
+}
+
+#[test]
+fn invalidate_first_and_only_checkpoint_without_tx_changes() {
+    let chain1 = chain!(checkpoints: [[0,h!("A")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    let chain2 = chain!(checkpoints: [[0,h!("A'")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [(0, Some(h!("A'")))],
+            txids: []
+        },)
+    );
+}
+
+#[test]
+fn invalidate_first_and_only_checkpoint_with_tx_move_forward() {
+    let chain1 = chain!(checkpoints: [[0,h!("A")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    let chain2 = chain!(checkpoints: [[0,h!("A'")],[1, h!("B")]], txids: [(h!("tx0"), TxHeight::Confirmed(1))]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [(0, Some(h!("A'"))), (1, Some(h!("B")))],
+            txids: [(h!("tx0"), Some(TxHeight::Confirmed(1)))]
+        },)
+    );
+}
+
+#[test]
+fn invalidate_first_and_only_checkpoint_with_tx_move_backward() {
+    let chain1 = chain!(checkpoints: [[1,h!("B")]], txids: [(h!("tx0"), TxHeight::Confirmed(1))]);
+    let chain2 = chain!(checkpoints: [[0,h!("A")],[1, h!("B'")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [(0, Some(h!("A"))), (1, Some(h!("B'")))],
+            txids: [(h!("tx0"), Some(TxHeight::Confirmed(0)))]
+        },)
+    );
+}
+
+#[test]
+fn invalidate_a_checkpoint_and_try_and_move_tx_when_it_wasnt_within_invalidation() {
+    let chain1 = chain!(checkpoints: [[0, h!("A")], [1, h!("B")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    let chain2 = chain!(checkpoints: [[0, h!("A")], [1, h!("B'")]], txids: [(h!("tx0"), TxHeight::Confirmed(1))]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Err(UpdateError::TxInconsistent {
+            txid: h!("tx0"),
+            original_pos: TxHeight::Confirmed(0),
+            update_pos: TxHeight::Confirmed(1),
+        })
+    );
+}
+
+/// This test doesn't make much sense. We're invalidating a block at height 1 and moving it to
+/// height 0. It should be impossible for it to be at height 1 at any point if it was at height 0
+/// all along.
+#[test]
+fn move_invalidated_tx_into_earlier_checkpoint() {
+    let chain1 = chain!(checkpoints: [[0, h!("A")], [1, h!("B")]], txids: [(h!("tx0"), TxHeight::Confirmed(1))]);
+    let chain2 = chain!(checkpoints: [[0, h!("A")], [1, h!("B'")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [(1, Some(h!("B'")))],
+            txids: [(h!("tx0"), Some(TxHeight::Confirmed(0)))]
+        },)
+    );
+}
+
+#[test]
+fn invalidate_first_and_only_checkpoint_with_tx_move_to_mempool() {
+    let chain1 = chain!(checkpoints: [[0,h!("A")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    let chain2 = chain!(checkpoints: [[0,h!("A'")]], txids: [(h!("tx0"), TxHeight::Unconfirmed)]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [(0, Some(h!("A'")))],
+            txids: [(h!("tx0"), Some(TxHeight::Unconfirmed))]
+        },)
+    );
+}
+
+#[test]
+fn confirm_tx_without_extending_chain() {
+    let chain1 = chain!(checkpoints: [[0,h!("A")]], txids: [(h!("tx0"), TxHeight::Unconfirmed)]);
+    let chain2 = chain!(checkpoints: [[0,h!("A")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [],
+            txids: [(h!("tx0"), Some(TxHeight::Confirmed(0)))]
+        },)
+    );
+}
+
+#[test]
+fn confirm_tx_backwards_while_extending_chain() {
+    let chain1 = chain!(checkpoints: [[0,h!("A")]], txids: [(h!("tx0"), TxHeight::Unconfirmed)]);
+    let chain2 = chain!(checkpoints: [[0,h!("A")],[1,h!("B")]], txids: [(h!("tx0"), TxHeight::Confirmed(0))]);
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [(1, Some(h!("B")))],
+            txids: [(h!("tx0"), Some(TxHeight::Confirmed(0)))]
+        },)
+    );
+}
+
+#[test]
+fn confirm_tx_in_new_block() {
+    let chain1 = chain!(checkpoints: [[0,h!("A")]], txids: [(h!("tx0"), TxHeight::Unconfirmed)]);
+    let chain2 = chain! {
+        checkpoints: [[0,h!("A")], [1,h!("B")]],
+        txids: [(h!("tx0"), TxHeight::Confirmed(1))]
+    };
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [(1, Some(h!("B")))],
+            txids: [(h!("tx0"), Some(TxHeight::Confirmed(1)))]
+        },)
+    );
+}
+
+#[test]
+fn merging_mempool_of_empty_chains_doesnt_fail() {
+    let chain1 = chain!(checkpoints: [], txids: [(h!("tx0"), TxHeight::Unconfirmed)]);
+    let chain2 = chain!(checkpoints: [], txids: [(h!("tx1"), TxHeight::Unconfirmed)]);
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [],
+            txids: [(h!("tx1"), Some(TxHeight::Unconfirmed))]
+        },)
+    );
+}
+
+#[test]
+fn cannot_insert_confirmed_tx_without_checkpoints() {
+    let chain = SparseChain::default();
+    assert_eq!(
+        chain.insert_tx_preview(h!("A"), TxHeight::Confirmed(0)),
+        Err(InsertTxError::TxTooHigh {
+            txid: h!("A"),
+            tx_height: 0,
+            tip_height: None
+        })
+    );
+}
+
+#[test]
+fn empty_chain_can_add_unconfirmed_transactions() {
+    let chain1 = chain!(checkpoints: [[0, h!("A")]], txids: []);
+    let chain2 = chain!(checkpoints: [], txids: [(h!("tx0"), TxHeight::Unconfirmed)]);
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [],
+            txids: [ (h!("tx0"), Some(TxHeight::Unconfirmed)) ]
+        },)
+    );
+}
+
+#[test]
+fn can_update_with_shorter_chain() {
+    let chain1 = chain!(checkpoints: [[1, h!("B")],[2, h!("C")]], txids: []);
+    let chain2 = chain!(checkpoints: [[1, h!("B")]], txids: [(h!("tx0"), TxHeight::Confirmed(1))]);
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [],
+            txids: [(h!("tx0"), Some(TxHeight::Confirmed(1)))]
+        },)
+    )
+}
+
+#[test]
+fn can_introduce_older_checkpoints() {
+    let chain1 = chain!(checkpoints: [[2, h!("C")], [3, h!("D")]], txids: []);
+    let chain2 = chain!(checkpoints: [[1, h!("B")], [2, h!("C")]], txids: []);
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [(1, Some(h!("B")))],
+            txids: []
+        },)
+    );
+}
+
+#[test]
+fn fix_blockhash_before_agreement_point() {
+    let chain1 = chain!([0, h!("im-wrong")], [1, h!("we-agree")]);
+    let chain2 = chain!([0, h!("fix")], [1, h!("we-agree")]);
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [(0, Some(h!("fix")))],
+            txids: []
+        },)
+    )
+}
+
+// TODO: Use macro
+#[test]
+fn cannot_change_ext_index_of_confirmed_tx() {
+    let chain1 = chain!(
+        index: TestIndex,
+        checkpoints: [[1, h!("A")]],
+        txids: [(h!("tx0"), TestIndex(TxHeight::Confirmed(1), 10))]
+    );
+    let chain2 = chain!(
+        index: TestIndex,
+        checkpoints: [[1, h!("A")]],
+        txids: [(h!("tx0"), TestIndex(TxHeight::Confirmed(1), 20))]
+    );
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Err(UpdateError::TxInconsistent {
+            txid: h!("tx0"),
+            original_pos: TestIndex(TxHeight::Confirmed(1), 10),
+            update_pos: TestIndex(TxHeight::Confirmed(1), 20),
+        }),
+    )
+}
+
+#[test]
+fn can_change_index_of_unconfirmed_tx() {
+    let chain1 = chain!(
+        index: TestIndex,
+        checkpoints: [[1, h!("A")]],
+        txids: [(h!("tx1"), TestIndex(TxHeight::Unconfirmed, 10))]
+    );
+    let chain2 = chain!(
+        index: TestIndex,
+        checkpoints: [[1, h!("A")]],
+        txids: [(h!("tx1"), TestIndex(TxHeight::Unconfirmed, 20))]
+    );
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(ChangeSet {
+            checkpoints: [].into(),
+            txids: [(h!("tx1"), Some(TestIndex(TxHeight::Unconfirmed, 20)),)].into()
+        },),
+    )
+}
+
+/// B and C are in both chain and update
+/// ```
+///        | 0 | 1 | 2 | 3 | 4
+/// chain  |     B   C
+/// update | A   B   C   D
+/// ```
+/// This should succeed with the point of agreement being C and A should be added in addition.
+#[test]
+fn two_points_of_agreement() {
+    let chain1 = chain!([1, h!("B")], [2, h!("C")]);
+    let chain2 = chain!([0, h!("A")], [1, h!("B")], [2, h!("C")], [3, h!("D")]);
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [(0, Some(h!("A"))), (3, Some(h!("D")))]
+        },),
+    );
+}
+
+/// Update and chain does not connect:
+/// ```
+///        | 0 | 1 | 2 | 3 | 4
+/// chain  |     B   C
+/// update | A   B       D
+/// ```
+/// This should fail as we cannot figure out whether C & D are on the same chain
+#[test]
+fn update_and_chain_does_not_connect() {
+    let chain1 = chain!([1, h!("B")], [2, h!("C")]);
+    let chain2 = chain!([0, h!("A")], [1, h!("B")], [3, h!("D")]);
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Err(UpdateError::NotConnected(2)),
+    );
+}
+
+/// Transient invalidation:
+/// ```
+///        | 0 | 1 | 2 | 3 | 4 | 5
+/// chain  | A       B   C       E
+/// update | A       B'  C'  D
+/// ```
+/// This should succeed and invalidate B,C and E with point of agreement being A.
+/// It should also invalidate transactions at height 1.
+#[test]
+fn transitive_invalidation_applies_to_checkpoints_higher_than_invalidation() {
+    let chain1 = chain! {
+        checkpoints: [[0, h!("A")], [2, h!("B")], [3, h!("C")], [5, h!("E")]],
+        txids: [
+            (h!("a"), TxHeight::Confirmed(0)),
+            (h!("b1"), TxHeight::Confirmed(1)),
+            (h!("b2"), TxHeight::Confirmed(2)),
+            (h!("d"), TxHeight::Confirmed(3)),
+            (h!("e"), TxHeight::Confirmed(5))
+        ]
+    };
+    let chain2 = chain! {
+        checkpoints: [[0, h!("A")], [2, h!("B'")], [3, h!("C'")], [4, h!("D")]],
+        txids: [(h!("b1"), TxHeight::Confirmed(4)), (h!("b2"), TxHeight::Confirmed(3))]
+    };
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [
+                (2, Some(h!("B'"))),
+                (3, Some(h!("C'"))),
+                (4, Some(h!("D"))),
+                (5, None)
+            ],
+            txids: [
+                (h!("b1"), Some(TxHeight::Confirmed(4))),
+                (h!("b2"), Some(TxHeight::Confirmed(3))),
+                (h!("d"), Some(TxHeight::Unconfirmed)),
+                (h!("e"), Some(TxHeight::Unconfirmed))
+            ]
+        },)
+    );
+}
+
+/// Transient invalidation:
+/// ```
+///        | 0 | 1 | 2 | 3 | 4
+/// chain  |     B   C       E
+/// update |     B'  C'  D
+/// ```
+///
+/// This should succeed and invalidate B, C and E with no point of agreement
+#[test]
+fn transitive_invalidation_applies_to_checkpoints_higher_than_invalidation_no_point_of_agreement() {
+    let chain1 = chain!([1, h!("B")], [2, h!("C")], [4, h!("E")]);
+    let chain2 = chain!([1, h!("B'")], [2, h!("C'")], [3, h!("D")]);
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [
+                (1, Some(h!("B'"))),
+                (2, Some(h!("C'"))),
+                (3, Some(h!("D"))),
+                (4, None)
+            ]
+        },)
+    )
+}
+
+/// Transient invalidation:
+/// ```
+///        | 0 | 1 | 2 | 3 | 4
+/// chain  | A   B   C       E
+/// update |     B'  C'  D
+/// ```
+///
+/// This should fail since although it tells us that B and C are invalid it doesn't tell us whether
+/// A was invalid.
+#[test]
+fn invalidation_but_no_connection() {
+    let chain1 = chain!([0, h!("A")], [1, h!("B")], [2, h!("C")], [4, h!("E")]);
+    let chain2 = chain!([1, h!("B'")], [2, h!("C'")], [3, h!("D")]);
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Err(UpdateError::NotConnected(0))
+    )
+}
+
+#[test]
+fn checkpoint_limit_is_respected() {
+    let mut chain1 = SparseChain::default();
+    let _ = chain1
+        .apply_update(chain!(
+            [1, h!("A")],
+            [2, h!("B")],
+            [3, h!("C")],
+            [4, h!("D")],
+            [5, h!("E")]
+        ))
+        .unwrap();
+
+    assert_eq!(chain1.checkpoints().len(), 5);
+    chain1.set_checkpoint_limit(Some(4));
+    assert_eq!(chain1.checkpoints().len(), 4);
+
+    let _ = chain1
+        .insert_checkpoint(BlockId {
+            height: 6,
+            hash: h!("F"),
+        })
+        .unwrap();
+    assert_eq!(chain1.checkpoints().len(), 4);
+
+    let changeset = chain1.determine_changeset(&chain!([6, h!("F")], [7, h!("G")]));
+    assert_eq!(changeset, Ok(changeset!(checkpoints: [(7, Some(h!("G")))])));
+
+    chain1.apply_changeset(changeset.unwrap());
+
+    assert_eq!(chain1.checkpoints().len(), 4);
+}
+
+#[test]
+fn range_txids_by_height() {
+    let mut chain = chain!(index: TestIndex, checkpoints: [[1, h!("block 1")], [2, h!("block 2")]]);
+
+    let txids: [(TestIndex, Txid); 4] = [
+        (
+            TestIndex(TxHeight::Confirmed(1), u32::MIN),
+            Txid::from_inner([0x00; 32]),
+        ),
+        (
+            TestIndex(TxHeight::Confirmed(1), u32::MAX),
+            Txid::from_inner([0xfe; 32]),
+        ),
+        (
+            TestIndex(TxHeight::Confirmed(2), u32::MIN),
+            Txid::from_inner([0x01; 32]),
+        ),
+        (
+            TestIndex(TxHeight::Confirmed(2), u32::MAX),
+            Txid::from_inner([0xff; 32]),
+        ),
+    ];
+
+    // populate chain with txids
+    for (index, txid) in txids {
+        let _ = chain.insert_tx(txid, index).expect("should succeed");
+    }
+
+    // inclusive start
+    assert_eq!(
+        chain
+            .range_txids_by_height(TxHeight::Confirmed(1)..)
+            .collect::<Vec<_>>(),
+        txids.iter().collect::<Vec<_>>(),
+    );
+
+    // exclusive start
+    assert_eq!(
+        chain
+            .range_txids_by_height((Bound::Excluded(TxHeight::Confirmed(1)), Bound::Unbounded,))
+            .collect::<Vec<_>>(),
+        txids[2..].iter().collect::<Vec<_>>(),
+    );
+
+    // inclusive end
+    assert_eq!(
+        chain
+            .range_txids_by_height((Bound::Unbounded, Bound::Included(TxHeight::Confirmed(2))))
+            .collect::<Vec<_>>(),
+        txids[..4].iter().collect::<Vec<_>>(),
+    );
+
+    // exclusive end
+    assert_eq!(
+        chain
+            .range_txids_by_height(..TxHeight::Confirmed(2))
+            .collect::<Vec<_>>(),
+        txids[..2].iter().collect::<Vec<_>>(),
+    );
+}
+
+#[test]
+fn range_txids_by_index() {
+    let mut chain = chain!(index: TestIndex, checkpoints: [[1, h!("block 1")],[2, h!("block 2")]]);
+
+    let txids: [(TestIndex, Txid); 4] = [
+        (TestIndex(TxHeight::Confirmed(1), u32::MIN), h!("tx 1 min")),
+        (TestIndex(TxHeight::Confirmed(1), u32::MAX), h!("tx 1 max")),
+        (TestIndex(TxHeight::Confirmed(2), u32::MIN), h!("tx 2 min")),
+        (TestIndex(TxHeight::Confirmed(2), u32::MAX), h!("tx 2 max")),
+    ];
+
+    // populate chain with txids
+    for (index, txid) in txids {
+        let _ = chain.insert_tx(txid, index).expect("should succeed");
+    }
+
+    // inclusive start
+    assert_eq!(
+        chain
+            .range_txids_by_position(TestIndex(TxHeight::Confirmed(1), u32::MIN)..)
+            .collect::<Vec<_>>(),
+        txids.iter().collect::<Vec<_>>(),
+    );
+    assert_eq!(
+        chain
+            .range_txids_by_position(TestIndex(TxHeight::Confirmed(1), u32::MAX)..)
+            .collect::<Vec<_>>(),
+        txids[1..].iter().collect::<Vec<_>>(),
+    );
+
+    // exclusive start
+    assert_eq!(
+        chain
+            .range_txids_by_position((
+                Bound::Excluded(TestIndex(TxHeight::Confirmed(1), u32::MIN)),
+                Bound::Unbounded
+            ))
+            .collect::<Vec<_>>(),
+        txids[1..].iter().collect::<Vec<_>>(),
+    );
+    assert_eq!(
+        chain
+            .range_txids_by_position((
+                Bound::Excluded(TestIndex(TxHeight::Confirmed(1), u32::MAX)),
+                Bound::Unbounded
+            ))
+            .collect::<Vec<_>>(),
+        txids[2..].iter().collect::<Vec<_>>(),
+    );
+
+    // inclusive end
+    assert_eq!(
+        chain
+            .range_txids_by_position((
+                Bound::Unbounded,
+                Bound::Included(TestIndex(TxHeight::Confirmed(2), u32::MIN))
+            ))
+            .collect::<Vec<_>>(),
+        txids[..3].iter().collect::<Vec<_>>(),
+    );
+    assert_eq!(
+        chain
+            .range_txids_by_position((
+                Bound::Unbounded,
+                Bound::Included(TestIndex(TxHeight::Confirmed(2), u32::MAX))
+            ))
+            .collect::<Vec<_>>(),
+        txids[..4].iter().collect::<Vec<_>>(),
+    );
+
+    // exclusive end
+    assert_eq!(
+        chain
+            .range_txids_by_position(..TestIndex(TxHeight::Confirmed(2), u32::MIN))
+            .collect::<Vec<_>>(),
+        txids[..2].iter().collect::<Vec<_>>(),
+    );
+    assert_eq!(
+        chain
+            .range_txids_by_position(..TestIndex(TxHeight::Confirmed(2), u32::MAX))
+            .collect::<Vec<_>>(),
+        txids[..3].iter().collect::<Vec<_>>(),
+    );
+}
+
+#[test]
+fn range_txids() {
+    let mut chain = SparseChain::default();
+
+    let txids = (0..100)
+        .map(|v| Txid::hash(v.to_string().as_bytes()))
+        .collect::<BTreeSet<Txid>>();
+
+    // populate chain
+    for txid in &txids {
+        let _ = chain
+            .insert_tx(*txid, TxHeight::Unconfirmed)
+            .expect("should succeed");
+    }
+
+    for txid in &txids {
+        assert_eq!(
+            chain
+                .range_txids((TxHeight::Unconfirmed, *txid)..)
+                .map(|(_, txid)| txid)
+                .collect::<Vec<_>>(),
+            txids.range(*txid..).collect::<Vec<_>>(),
+            "range with inclusive start should succeed"
+        );
+
+        assert_eq!(
+            chain
+                .range_txids((
+                    Bound::Excluded((TxHeight::Unconfirmed, *txid)),
+                    Bound::Unbounded,
+                ))
+                .map(|(_, txid)| txid)
+                .collect::<Vec<_>>(),
+            txids
+                .range((Bound::Excluded(*txid), Bound::Unbounded,))
+                .collect::<Vec<_>>(),
+            "range with exclusive start should succeed"
+        );
+
+        assert_eq!(
+            chain
+                .range_txids(..(TxHeight::Unconfirmed, *txid))
+                .map(|(_, txid)| txid)
+                .collect::<Vec<_>>(),
+            txids.range(..*txid).collect::<Vec<_>>(),
+            "range with exclusive end should succeed"
+        );
+
+        assert_eq!(
+            chain
+                .range_txids((
+                    Bound::Included((TxHeight::Unconfirmed, *txid)),
+                    Bound::Unbounded,
+                ))
+                .map(|(_, txid)| txid)
+                .collect::<Vec<_>>(),
+            txids
+                .range((Bound::Included(*txid), Bound::Unbounded,))
+                .collect::<Vec<_>>(),
+            "range with inclusive end should succeed"
+        );
+    }
+}
+
+#[test]
+fn invalidated_txs_move_to_unconfirmed() {
+    let chain1 = chain! {
+        checkpoints: [[0, h!("A")], [1, h!("B")], [2, h!("C")]],
+        txids: [
+            (h!("a"), TxHeight::Confirmed(0)),
+            (h!("b"), TxHeight::Confirmed(1)),
+            (h!("c"), TxHeight::Confirmed(2)),
+            (h!("d"), TxHeight::Unconfirmed)
+        ]
+    };
+
+    let chain2 = chain!([0, h!("A")], [1, h!("B'")]);
+
+    assert_eq!(
+        chain1.determine_changeset(&chain2),
+        Ok(changeset! {
+            checkpoints: [
+                (1, Some(h!("B'"))),
+                (2, None)
+            ],
+            txids: [
+                (h!("b"), Some(TxHeight::Unconfirmed)),
+                (h!("c"), Some(TxHeight::Unconfirmed))
+            ]
+        },)
+    );
+}
+
+#[test]
+fn change_tx_position_from_unconfirmed_to_confirmed() {
+    let mut chain = SparseChain::<TxHeight>::default();
+    let txid = h!("txid");
+
+    let _ = chain.insert_tx(txid, TxHeight::Unconfirmed).unwrap();
+
+    assert_eq!(chain.tx_position(txid), Some(&TxHeight::Unconfirmed));
+    let _ = chain
+        .insert_checkpoint(BlockId {
+            height: 0,
+            hash: h!("0"),
+        })
+        .unwrap();
+    let _ = chain.insert_tx(txid, TxHeight::Confirmed(0)).unwrap();
+
+    assert_eq!(chain.tx_position(txid), Some(&TxHeight::Confirmed(0)));
+}
--- a/crates/chain/tests/test_spk_txout_index.rs
+++ b/crates/chain/tests/test_spk_txout_index.rs
@@ -1,28 +1,28 @@
-use bdk_chain::{indexed_tx_graph::Indexer, SpkTxOutIndex};
-use bitcoin::{absolute, transaction, Amount, OutPoint, ScriptBuf, Transaction, TxIn, TxOut};
+use bdk_chain::SpkTxOutIndex;
+use bitcoin::{hashes::hex::FromHex, OutPoint, PackedLockTime, Script, Transaction, TxIn, TxOut};

 #[test]
 fn spk_txout_sent_and_received() {
-    let spk1 = ScriptBuf::from_hex("001404f1e52ce2bab3423c6a8c63b7cd730d8f12542c").unwrap();
-    let spk2 = ScriptBuf::from_hex("00142b57404ae14f08c3a0c903feb2af7830605eb00f").unwrap();
+    let spk1 = Script::from_hex("001404f1e52ce2bab3423c6a8c63b7cd730d8f12542c").unwrap();
+    let spk2 = Script::from_hex("00142b57404ae14f08c3a0c903feb2af7830605eb00f").unwrap();

    let mut index = SpkTxOutIndex::default();
    index.insert_spk(0, spk1.clone());
    index.insert_spk(1, spk2.clone());

    let tx1 = Transaction {
-        version: transaction::Version::TWO,
-        lock_time: absolute::LockTime::ZERO,
+        version: 0x02,
+        lock_time: PackedLockTime(0),
        input: vec![],
        output: vec![TxOut {
-            value: Amount::from_sat(42_000),
+            value: 42_000,
            script_pubkey: spk1.clone(),
        }],
    };

    assert_eq!(index.sent_and_received(&tx1), (0, 42_000));
    assert_eq!(index.net_value(&tx1), 42_000);
-    index.index_tx(&tx1);
+    index.scan(&tx1);
    assert_eq!(
        index.sent_and_received(&tx1),
        (0, 42_000),
@@ -30,8 +30,8 @@ fn spk_txout_sent_and_received() {
    );

    let tx2 = Transaction {
-        version: transaction::Version::ONE,
-        lock_time: absolute::LockTime::ZERO,
+        version: 0x1,
+        lock_time: PackedLockTime(0),
        input: vec![TxIn {
            previous_output: OutPoint {
                txid: tx1.txid(),
@@ -41,12 +41,12 @@ fn spk_txout_sent_and_received() {
        }],
        output: vec![
            TxOut {
-                value: Amount::from_sat(20_000),
+                value: 20_000,
                script_pubkey: spk2,
            },
            TxOut {
                script_pubkey: spk1,
-                value: Amount::from_sat(30_000),
+                value: 30_000,
            },
        ],
    };
@@ -57,8 +57,8 @@ fn spk_txout_sent_and_received() {

 #[test]
 fn mark_used() {
-    let spk1 = ScriptBuf::from_hex("001404f1e52ce2bab3423c6a8c63b7cd730d8f12542c").unwrap();
-    let spk2 = ScriptBuf::from_hex("00142b57404ae14f08c3a0c903feb2af7830605eb00f").unwrap();
+    let spk1 = Script::from_hex("001404f1e52ce2bab3423c6a8c63b7cd730d8f12542c").unwrap();
+    let spk2 = Script::from_hex("00142b57404ae14f08c3a0c903feb2af7830605eb00f").unwrap();

    let mut spk_index = SpkTxOutIndex::default();
    spk_index.insert_spk(1, spk1.clone());
@@ -73,16 +73,16 @@ fn mark_used() {
    assert!(spk_index.is_used(&1));

    let tx1 = Transaction {
-        version: transaction::Version::TWO,
-        lock_time: absolute::LockTime::ZERO,
+        version: 0x02,
+        lock_time: PackedLockTime(0),
        input: vec![],
        output: vec![TxOut {
-            value: Amount::from_sat(42_000),
+            value: 42_000,
            script_pubkey: spk1,
        }],
    };

-    spk_index.index_tx(&tx1);
+    spk_index.scan(&tx1);
    spk_index.unmark_used(&1);
    assert!(
        spk_index.is_used(&1),
--- a/crates/chain/tests/test_tx_graph.rs
+++ b/crates/chain/tests/test_tx_graph.rs
--- a/crates/chain/tests/test_tx_graph_conflicts.rs
+++ b/crates/chain/tests/test_tx_graph_conflicts.rs
@@ -1,668 +0,0 @@
-#[macro_use]
-mod common;
-
-use std::collections::{BTreeSet, HashSet};
-
-use bdk_chain::{keychain::Balance, BlockId};
-use bitcoin::{OutPoint, Script};
-use common::*;
-
-#[allow(dead_code)]
-struct Scenario<'a> {
-    /// Name of the test scenario
-    name: &'a str,
-    /// Transaction templates
-    tx_templates: &'a [TxTemplate<'a, BlockId>],
-    /// Names of txs that must exist in the output of `list_chain_txs`
-    exp_chain_txs: HashSet<&'a str>,
-    /// Outpoints that must exist in the output of `filter_chain_txouts`
-    exp_chain_txouts: HashSet<(&'a str, u32)>,
-    /// Outpoints of UTXOs that must exist in the output of `filter_chain_unspents`
-    exp_unspents: HashSet<(&'a str, u32)>,
-    /// Expected balances
-    exp_balance: Balance,
-}
-
-/// This test ensures that [`TxGraph`] will reliably filter out irrelevant transactions when
-/// presented with multiple conflicting transaction scenarios using the [`TxTemplate`] structure.
-/// This test also checks that [`TxGraph::list_chain_txs`], [`TxGraph::filter_chain_txouts`],
-/// [`TxGraph::filter_chain_unspents`], and [`TxGraph::balance`] return correct data.
-#[test]
-fn test_tx_conflict_handling() {
-    // Create Local chains
-    let local_chain = local_chain!(
-        (0, h!("A")),
-        (1, h!("B")),
-        (2, h!("C")),
-        (3, h!("D")),
-        (4, h!("E")),
-        (5, h!("F")),
-        (6, h!("G"))
-    );
-    let chain_tip = local_chain.tip().block_id();
-
-    let scenarios = [
-        Scenario {
-            name: "coinbase tx cannot be in mempool and be unconfirmed",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "unconfirmed_coinbase",
-                    inputs: &[TxInTemplate::Coinbase],
-                    outputs: &[TxOutTemplate::new(5000, Some(0))],
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "confirmed_genesis",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(1))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                },
-                TxTemplate {
-                    tx_name: "unconfirmed_conflict",
-                    inputs: &[
-                        TxInTemplate::PrevTx("confirmed_genesis", 0), 
-                        TxInTemplate::PrevTx("unconfirmed_coinbase", 0)
-                    ],
-                    outputs: &[TxOutTemplate::new(20000, Some(2))],
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "confirmed_conflict",
-                    inputs: &[TxInTemplate::PrevTx("confirmed_genesis", 0)],
-                    outputs: &[TxOutTemplate::new(20000, Some(3))],
-                    anchors: &[block_id!(4, "E")],
-                    ..Default::default()
-                },
-            ],
-            exp_chain_txs: HashSet::from(["confirmed_genesis", "confirmed_conflict"]),
-            exp_chain_txouts: HashSet::from([("confirmed_genesis", 0), ("confirmed_conflict", 0)]),
-            exp_unspents: HashSet::from([("confirmed_conflict", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 0,
-                untrusted_pending: 0,
-                confirmed: 20000,
-            },
-        },
-        Scenario {
-            name: "2 unconfirmed txs with same last_seens conflict",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "tx1",
-                    outputs: &[TxOutTemplate::new(40000, Some(0))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_1",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0)],
-                    outputs: &[TxOutTemplate::new(20000, Some(2))],
-                    last_seen: Some(300),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_2",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0)],
-                    outputs: &[TxOutTemplate::new(30000, Some(3))],
-                    last_seen: Some(300),
-                    ..Default::default()
-                },
-            ],
-            // the txgraph is going to pick tx_conflict_2 because of higher lexicographical txid
-            exp_chain_txs: HashSet::from(["tx1", "tx_conflict_2"]),
-            exp_chain_txouts: HashSet::from([("tx1", 0), ("tx_conflict_2", 0)]),
-            exp_unspents: HashSet::from([("tx_conflict_2", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 30000,
-                untrusted_pending: 0,
-                confirmed: 0,
-            },
-        },
-        Scenario {
-            name: "2 unconfirmed txs with different last_seens conflict",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "tx1",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(0)), TxOutTemplate::new(10000, Some(1))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_1",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0), TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(20000, Some(2))],
-                    last_seen: Some(200),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_2",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0),  TxInTemplate::PrevTx("tx1", 1)],
-                    outputs: &[TxOutTemplate::new(30000, Some(3))],
-                    last_seen: Some(300),
-                    ..Default::default()
-                },
-            ],
-            exp_chain_txs: HashSet::from(["tx1", "tx_conflict_2"]),
-            exp_chain_txouts: HashSet::from([("tx1", 0), ("tx1", 1), ("tx_conflict_2", 0)]),
-            exp_unspents: HashSet::from([("tx_conflict_2", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 30000,
-                untrusted_pending: 0,
-                confirmed: 0,
-            },
-        },
-        Scenario {
-            name: "3 unconfirmed txs with different last_seens conflict",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "tx1",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(0))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_1",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0), TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(20000, Some(1))],
-                    last_seen: Some(200),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_2",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0)],
-                    outputs: &[TxOutTemplate::new(30000, Some(2))],
-                    last_seen: Some(300),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_3",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0)],
-                    outputs: &[TxOutTemplate::new(40000, Some(3))],
-                    last_seen: Some(400),
-                    ..Default::default()
-                },
-            ],
-            exp_chain_txs: HashSet::from(["tx1", "tx_conflict_3"]),
-            exp_chain_txouts: HashSet::from([("tx1", 0), ("tx_conflict_3", 0)]),
-            exp_unspents: HashSet::from([("tx_conflict_3", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 40000,
-                untrusted_pending: 0,
-                confirmed: 0,
-            },
-        },
-        Scenario {
-            name: "unconfirmed tx conflicts with tx in orphaned block, orphaned higher last_seen",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "tx1",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(0))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_1",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0), TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(20000, Some(1))],
-                    last_seen: Some(200),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "tx_orphaned_conflict",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0)],
-                    outputs: &[TxOutTemplate::new(30000, Some(2))],
-                    anchors: &[block_id!(4, "Orphaned Block")],
-                    last_seen: Some(300),
-                },
-            ],
-            exp_chain_txs: HashSet::from(["tx1", "tx_orphaned_conflict"]),
-            exp_chain_txouts: HashSet::from([("tx1", 0), ("tx_orphaned_conflict", 0)]),
-            exp_unspents: HashSet::from([("tx_orphaned_conflict", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 30000,
-                untrusted_pending: 0,
-                confirmed: 0,
-            },
-        },
-        Scenario {
-            name: "unconfirmed tx conflicts with tx in orphaned block, orphaned lower last_seen",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "tx1",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(0))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_1",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0), TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(20000, Some(1))],
-                    last_seen: Some(200),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "tx_orphaned_conflict",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0)],
-                    outputs: &[TxOutTemplate::new(30000, Some(2))],
-                    anchors: &[block_id!(4, "Orphaned Block")],
-                    last_seen: Some(100),
-                },
-            ],
-            exp_chain_txs: HashSet::from(["tx1", "tx_conflict_1"]),
-            exp_chain_txouts: HashSet::from([("tx1", 0), ("tx_conflict_1", 0)]),
-            exp_unspents: HashSet::from([("tx_conflict_1", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 20000,
-                untrusted_pending: 0,
-                confirmed: 0,
-            },
-        },
-        Scenario {
-            name: "multiple unconfirmed txs conflict with a confirmed tx",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "tx1",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(0))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_1",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0), TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(20000, Some(1))],
-                    last_seen: Some(200),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_2",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0)],
-                    outputs: &[TxOutTemplate::new(30000, Some(2))],
-                    last_seen: Some(300),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "tx_conflict_3",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0)],
-                    outputs: &[TxOutTemplate::new(40000, Some(3))],
-                    last_seen: Some(400),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "tx_confirmed_conflict",
-                    inputs: &[TxInTemplate::PrevTx("tx1", 0)],
-                    outputs: &[TxOutTemplate::new(50000, Some(4))],
-                    anchors: &[block_id!(1, "B")],
-                    ..Default::default()
-                },
-            ],
-            exp_chain_txs: HashSet::from(["tx1", "tx_confirmed_conflict"]),
-            exp_chain_txouts: HashSet::from([("tx1", 0), ("tx_confirmed_conflict", 0)]),
-            exp_unspents: HashSet::from([("tx_confirmed_conflict", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 0,
-                untrusted_pending: 0,
-                confirmed: 50000,
-            },
-        },
-        Scenario {
-            name: "B and B' spend A and conflict, C spends B, all the transactions are unconfirmed, B' has higher last_seen than B",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "A",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(0))],
-                    last_seen: Some(22),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "B",
-                    inputs: &[TxInTemplate::PrevTx("A", 0)],
-                    outputs: &[TxOutTemplate::new(20000, Some(1))],
-                    last_seen: Some(23),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "B'",
-                    inputs: &[TxInTemplate::PrevTx("A", 0)],
-                    outputs: &[TxOutTemplate::new(20000, Some(2))],
-                    last_seen: Some(24),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "C",
-                    inputs: &[TxInTemplate::PrevTx("B", 0)],
-                    outputs: &[TxOutTemplate::new(30000, Some(3))],
-                    last_seen: Some(25),
-                    ..Default::default()
-                },
-            ],
-            // A, B, C will appear in the list methods
-            // This is because B' has a higher last seen than B, but C has a higher
-            // last seen than B', so B and C are considered canonical
-            exp_chain_txs: HashSet::from(["A", "B", "C"]),
-            exp_chain_txouts: HashSet::from([("A", 0), ("B", 0), ("C", 0)]),
-            exp_unspents: HashSet::from([("C", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 30000,
-                untrusted_pending: 0,
-                confirmed: 0,
-            },
-        },
-        Scenario {
-            name: "B and B' spend A and conflict, C spends B, A and B' are in best chain",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "A",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(0))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                },
-                TxTemplate {
-                    tx_name: "B",
-                    inputs: &[TxInTemplate::PrevTx("A", 0)],
-                    outputs: &[TxOutTemplate::new(20000, Some(1))],
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "B'",
-                    inputs: &[TxInTemplate::PrevTx("A", 0)],
-                    outputs: &[TxOutTemplate::new(20000, Some(2))],
-                    anchors: &[block_id!(4, "E")],
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "C",
-                    inputs: &[TxInTemplate::PrevTx("B", 0)],
-                    outputs: &[TxOutTemplate::new(30000, Some(3))],
-                    ..Default::default()
-                },
-            ],
-            // B and C should not appear in the list methods
-            exp_chain_txs: HashSet::from(["A", "B'"]),
-            exp_chain_txouts: HashSet::from([("A", 0), ("B'", 0)]),
-            exp_unspents: HashSet::from([("B'", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 0,
-                untrusted_pending: 0,
-                confirmed: 20000,
-            },
-        },
-        Scenario {
-            name: "B and B' spend A and conflict, C spends B', A and B' are in best chain",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "A",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(0))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                },
-                TxTemplate {
-                    tx_name: "B",
-                    inputs: &[TxInTemplate::PrevTx("A", 0)],
-                    outputs: &[TxOutTemplate::new(20000, Some(1))],
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "B'",
-                    inputs: &[TxInTemplate::PrevTx("A", 0)],
-                    outputs: &[TxOutTemplate::new(20000, Some(2))],
-                    anchors: &[block_id!(4, "E")],
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "C",
-                    inputs: &[TxInTemplate::PrevTx("B'", 0)],
-                    outputs: &[TxOutTemplate::new(30000, Some(3))],
-                    ..Default::default()
-                },
-            ],
-            // B should not appear in the list methods
-            exp_chain_txs: HashSet::from(["A", "B'", "C"]),
-            exp_chain_txouts: HashSet::from([
-                ("A", 0),
-                ("B'", 0),
-                ("C", 0),
-            ]),
-            exp_unspents: HashSet::from([("C", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 30000,
-                untrusted_pending: 0,
-                confirmed: 0,
-            },
-        },
-        Scenario {
-            name: "B and B' spend A and conflict, C spends both B and B', A is in best chain",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "A",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(0))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                },
-                TxTemplate {
-                    tx_name: "B",
-                    inputs: &[TxInTemplate::PrevTx("A", 0), TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(20000, Some(1))],
-                    last_seen: Some(200),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "B'",
-                    inputs: &[TxInTemplate::PrevTx("A", 0)],
-                    outputs: &[TxOutTemplate::new(30000, Some(2))],
-                    last_seen: Some(300),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "C",
-                    inputs: &[
-                        TxInTemplate::PrevTx("B", 0),
-                        TxInTemplate::PrevTx("B'", 0),
-                    ],
-                    outputs: &[TxOutTemplate::new(20000, Some(3))],
-                    ..Default::default()
-                },
-            ],
-            // C should not appear in the list methods
-            exp_chain_txs: HashSet::from(["A", "B'"]),
-            exp_chain_txouts: HashSet::from([("A", 0), ("B'", 0)]),
-            exp_unspents: HashSet::from([("B'", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 30000,
-                untrusted_pending: 0,
-                confirmed: 0,
-            },
-        },
-        Scenario {
-            name: "B and B' spend A and conflict, B' is confirmed, C spends both B and B', A is in best chain",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "A",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(0))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                },
-                TxTemplate {
-                    tx_name: "B",
-                    inputs: &[TxInTemplate::PrevTx("A", 0), TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(20000, Some(1))],
-                    last_seen: Some(200),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "B'",
-                    inputs: &[TxInTemplate::PrevTx("A", 0)],
-                    outputs: &[TxOutTemplate::new(50000, Some(4))],
-                    anchors: &[block_id!(1, "B")],
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "C",
-                    inputs: &[
-                        TxInTemplate::PrevTx("B", 0),
-                        TxInTemplate::PrevTx("B'", 0),
-                    ],
-                    outputs: &[TxOutTemplate::new(20000, Some(5))],
-                    ..Default::default()
-                },
-            ],
-            // C should not appear in the list methods
-            exp_chain_txs: HashSet::from(["A", "B'"]),
-            exp_chain_txouts: HashSet::from([("A", 0), ("B'", 0)]),
-            exp_unspents: HashSet::from([("B'", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 0,
-                untrusted_pending: 0,
-                confirmed: 50000,
-            },
-        },
-        Scenario {
-            name: "B and B' spend A and conflict, B' is confirmed, C spends both B and B', D spends C, A is in best chain",
-            tx_templates: &[
-                TxTemplate {
-                    tx_name: "A",
-                    inputs: &[TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(10000, Some(0))],
-                    anchors: &[block_id!(1, "B")],
-                    last_seen: None,
-                },
-                TxTemplate {
-                    tx_name: "B",
-                    inputs: &[TxInTemplate::PrevTx("A", 0), TxInTemplate::Bogus],
-                    outputs: &[TxOutTemplate::new(20000, Some(1))],
-                    last_seen: Some(200),
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "B'",
-                    inputs: &[TxInTemplate::PrevTx("A", 0)],
-                    outputs: &[TxOutTemplate::new(50000, Some(4))],
-                    anchors: &[block_id!(1, "B")],
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "C",
-                    inputs: &[
-                        TxInTemplate::PrevTx("B", 0),
-                        TxInTemplate::PrevTx("B'", 0),
-                    ],
-                    outputs: &[TxOutTemplate::new(20000, Some(5))],
-                    ..Default::default()
-                },
-                TxTemplate {
-                    tx_name: "D",
-                    inputs: &[TxInTemplate::PrevTx("C", 0)],
-                    outputs: &[TxOutTemplate::new(20000, Some(6))],
-                    ..Default::default()
-                },
-            ],
-            // D should not appear in the list methods
-            exp_chain_txs: HashSet::from(["A", "B'"]),
-            exp_chain_txouts: HashSet::from([("A", 0), ("B'", 0)]),
-            exp_unspents: HashSet::from([("B'", 0)]),
-            exp_balance: Balance {
-                immature: 0,
-                trusted_pending: 0,
-                untrusted_pending: 0,
-                confirmed: 50000,
-            },
-        },
-    ];
-
-    for scenario in scenarios {
-        let (tx_graph, spk_index, exp_tx_ids) = init_graph(scenario.tx_templates.iter());
-
-        let txs = tx_graph
-            .list_chain_txs(&local_chain, chain_tip)
-            .map(|tx| tx.tx_node.txid)
-            .collect::<BTreeSet<_>>();
-        let exp_txs = scenario
-            .exp_chain_txs
-            .iter()
-            .map(|txid| *exp_tx_ids.get(txid).expect("txid must exist"))
-            .collect::<BTreeSet<_>>();
-        assert_eq!(
-            txs, exp_txs,
-            "\n[{}] 'list_chain_txs' failed",
-            scenario.name
-        );
-
-        let txouts = tx_graph
-            .filter_chain_txouts(
-                &local_chain,
-                chain_tip,
-                spk_index.outpoints().iter().cloned(),
-            )
-            .map(|(_, full_txout)| full_txout.outpoint)
-            .collect::<BTreeSet<_>>();
-        let exp_txouts = scenario
-            .exp_chain_txouts
-            .iter()
-            .map(|(txid, vout)| OutPoint {
-                txid: *exp_tx_ids.get(txid).expect("txid must exist"),
-                vout: *vout,
-            })
-            .collect::<BTreeSet<_>>();
-        assert_eq!(
-            txouts, exp_txouts,
-            "\n[{}] 'filter_chain_txouts' failed",
-            scenario.name
-        );
-
-        let utxos = tx_graph
-            .filter_chain_unspents(
-                &local_chain,
-                chain_tip,
-                spk_index.outpoints().iter().cloned(),
-            )
-            .map(|(_, full_txout)| full_txout.outpoint)
-            .collect::<BTreeSet<_>>();
-        let exp_utxos = scenario
-            .exp_unspents
-            .iter()
-            .map(|(txid, vout)| OutPoint {
-                txid: *exp_tx_ids.get(txid).expect("txid must exist"),
-                vout: *vout,
-            })
-            .collect::<BTreeSet<_>>();
-        assert_eq!(
-            utxos, exp_utxos,
-            "\n[{}] 'filter_chain_unspents' failed",
-            scenario.name
-        );
-
-        let balance = tx_graph.balance(
-            &local_chain,
-            chain_tip,
-            spk_index.outpoints().iter().cloned(),
-            |_, spk: &Script| spk_index.index_of_spk(spk).is_some(),
-        );
-        assert_eq!(
-            balance, scenario.exp_balance,
-            "\n[{}] 'balance' failed",
-            scenario.name
-        );
-    }
-}
--- a/crates/electrum/Cargo.toml
+++ b/crates/electrum/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "bdk_electrum"
-version = "0.11.0"
+version = "0.2.0"
 edition = "2021"
 homepage = "https://bitcoindevkit.org"
 repository = "https://github.com/bitcoindevkit/bdk"
@@ -12,11 +12,5 @@ readme = "README.md"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

 [dependencies]
-bdk_chain = { path = "../chain", version = "0.12.0", default-features = false }
-electrum-client = { version = "0.19" }
-#rustls = { version = "=0.21.1", optional = true, features = ["dangerous_configuration"] }
-
-[dev-dependencies]
-bdk_testenv = { path = "../testenv", default-features = false }
-electrsd = { version= "0.27.1", features = ["bitcoind_25_0", "esplora_a33e97e1", "legacy"] }
-anyhow = "1"
+bdk_chain = { path = "../chain", version = "0.4.0", features = ["serde", "miniscript"] }
+electrum-client = { version = "0.12" }
--- a/crates/electrum/README.md
+++ b/crates/electrum/README.md
@@ -1,7 +1,3 @@
 # BDK Electrum

-BDK Electrum extends [`electrum-client`] to update [`bdk_chain`] structures
-from an Electrum server.
-
-[`electrum-client`]: https://docs.rs/electrum-client/
-[`bdk_chain`]: https://docs.rs/bdk-chain/
+BDK Electrum client library for updating the keychain tracker.
--- a/crates/electrum/src/electrum_ext.rs
+++ b/crates/electrum/src/electrum_ext.rs
@@ -1,554 +0,0 @@
-use bdk_chain::{
-    bitcoin::{OutPoint, ScriptBuf, Transaction, Txid},
-    local_chain::{self, CheckPoint},
-    tx_graph::{self, TxGraph},
-    Anchor, BlockId, ConfirmationHeightAnchor, ConfirmationTimeHeightAnchor,
-};
-use electrum_client::{Client, ElectrumApi, Error, HeaderNotification};
-use std::{
-    collections::{BTreeMap, BTreeSet, HashMap, HashSet},
-    fmt::Debug,
-    str::FromStr,
-};
-
-/// We include a chain suffix of a certain length for the purpose of robustness.
-const CHAIN_SUFFIX_LENGTH: u32 = 8;
-
-/// Represents updates fetched from an Electrum server, but excludes full transactions.
-///
-/// To provide a complete update to [`TxGraph`], you'll need to call [`Self::missing_full_txs`] to
-/// determine the full transactions missing from [`TxGraph`]. Then call [`Self::into_tx_graph`] to
-/// fetch the full transactions from Electrum and finalize the update.
-#[derive(Debug, Default, Clone)]
-pub struct RelevantTxids(HashMap<Txid, BTreeSet<ConfirmationHeightAnchor>>);
-
-impl RelevantTxids {
-    /// Determine the full transactions that are missing from `graph`.
-    ///
-    /// Refer to [`RelevantTxids`] for more details.
-    pub fn missing_full_txs<A: Anchor>(&self, graph: &TxGraph<A>) -> Vec<Txid> {
-        self.0
-            .keys()
-            .filter(move |&&txid| graph.as_ref().get_tx(txid).is_none())
-            .cloned()
-            .collect()
-    }
-
-    /// Finalizes the [`TxGraph`] update by fetching `missing` txids from the `client`.
-    ///
-    /// Refer to [`RelevantTxids`] for more details.
-    pub fn into_tx_graph(
-        self,
-        client: &Client,
-        missing: Vec<Txid>,
-    ) -> Result<TxGraph<ConfirmationHeightAnchor>, Error> {
-        let new_txs = client.batch_transaction_get(&missing)?;
-        let mut graph = TxGraph::<ConfirmationHeightAnchor>::new(new_txs);
-        for (txid, anchors) in self.0 {
-            for anchor in anchors {
-                let _ = graph.insert_anchor(txid, anchor);
-            }
-        }
-        Ok(graph)
-    }
-
-    /// Finalizes the update by fetching `missing` txids from the `client`, where the
-    /// resulting [`TxGraph`] has anchors of type [`ConfirmationTimeHeightAnchor`].
-    ///
-    /// Refer to [`RelevantTxids`] for more details.
-    ///
-    /// **Note:** The confirmation time might not be precisely correct if there has been a reorg.
-    // Electrum's API intends that we use the merkle proof API, we should change `bdk_electrum` to
-    // use it.
-    pub fn into_confirmation_time_tx_graph(
-        self,
-        client: &Client,
-        missing: Vec<Txid>,
-    ) -> Result<TxGraph<ConfirmationTimeHeightAnchor>, Error> {
-        let graph = self.into_tx_graph(client, missing)?;
-
-        let relevant_heights = {
-            let mut visited_heights = HashSet::new();
-            graph
-                .all_anchors()
-                .iter()
-                .map(|(a, _)| a.confirmation_height_upper_bound())
-                .filter(move |&h| visited_heights.insert(h))
-                .collect::<Vec<_>>()
-        };
-
-        let height_to_time = relevant_heights
-            .clone()
-            .into_iter()
-            .zip(
-                client
-                    .batch_block_header(relevant_heights)?
-                    .into_iter()
-                    .map(|bh| bh.time as u64),
-            )
-            .collect::<HashMap<u32, u64>>();
-
-        let graph_changeset = {
-            let old_changeset = TxGraph::default().apply_update(graph);
-            tx_graph::ChangeSet {
-                txs: old_changeset.txs,
-                txouts: old_changeset.txouts,
-                last_seen: old_changeset.last_seen,
-                anchors: old_changeset
-                    .anchors
-                    .into_iter()
-                    .map(|(height_anchor, txid)| {
-                        let confirmation_height = height_anchor.confirmation_height;
-                        let confirmation_time = height_to_time[&confirmation_height];
-                        let time_anchor = ConfirmationTimeHeightAnchor {
-                            anchor_block: height_anchor.anchor_block,
-                            confirmation_height,
-                            confirmation_time,
-                        };
-                        (time_anchor, txid)
-                    })
-                    .collect(),
-            }
-        };
-
-        let mut new_graph = TxGraph::default();
-        new_graph.apply_changeset(graph_changeset);
-        Ok(new_graph)
-    }
-}
-
-/// Combination of chain and transactions updates from electrum
-///
-/// We have to update the chain and the txids at the same time since we anchor the txids to
-/// the same chain tip that we check before and after we gather the txids.
-#[derive(Debug)]
-pub struct ElectrumUpdate {
-    /// Chain update
-    pub chain_update: local_chain::Update,
-    /// Transaction updates from electrum
-    pub relevant_txids: RelevantTxids,
-}
-
-/// Trait to extend [`Client`] functionality.
-pub trait ElectrumExt {
-    /// Full scan the keychain scripts specified with the blockchain (via an Electrum client) and
-    /// returns updates for [`bdk_chain`] data structures.
-    ///
-    /// - `prev_tip`: the most recent blockchain tip present locally
-    /// - `keychain_spks`: keychains that we want to scan transactions for
-    ///
-    /// The full scan for each keychain stops after a gap of `stop_gap` script pubkeys with no associated
-    /// transactions. `batch_size` specifies the max number of script pubkeys to request for in a
-    /// single batch request.
-    fn full_scan<K: Ord + Clone>(
-        &self,
-        prev_tip: CheckPoint,
-        keychain_spks: BTreeMap<K, impl IntoIterator<Item = (u32, ScriptBuf)>>,
-        stop_gap: usize,
-        batch_size: usize,
-    ) -> Result<(ElectrumUpdate, BTreeMap<K, u32>), Error>;
-
-    /// Sync a set of scripts with the blockchain (via an Electrum client) for the data specified
-    /// and returns updates for [`bdk_chain`] data structures.
-    ///
-    /// - `prev_tip`: the most recent blockchain tip present locally
-    /// - `misc_spks`: an iterator of scripts we want to sync transactions for
-    /// - `txids`: transactions for which we want updated [`Anchor`]s
-    /// - `outpoints`: transactions associated with these outpoints (residing, spending) that we
-    ///     want to include in the update
-    ///
-    /// `batch_size` specifies the max number of script pubkeys to request for in a single batch
-    /// request.
-    ///
-    /// If the scripts to sync are unknown, such as when restoring or importing a keychain that
-    /// may include scripts that have been used, use [`full_scan`] with the keychain.
-    ///
-    /// [`full_scan`]: ElectrumExt::full_scan
-    fn sync(
-        &self,
-        prev_tip: CheckPoint,
-        misc_spks: impl IntoIterator<Item = ScriptBuf>,
-        txids: impl IntoIterator<Item = Txid>,
-        outpoints: impl IntoIterator<Item = OutPoint>,
-        batch_size: usize,
-    ) -> Result<ElectrumUpdate, Error>;
-}
-
-impl<A: ElectrumApi> ElectrumExt for A {
-    fn full_scan<K: Ord + Clone>(
-        &self,
-        prev_tip: CheckPoint,
-        keychain_spks: BTreeMap<K, impl IntoIterator<Item = (u32, ScriptBuf)>>,
-        stop_gap: usize,
-        batch_size: usize,
-    ) -> Result<(ElectrumUpdate, BTreeMap<K, u32>), Error> {
-        let mut request_spks = keychain_spks
-            .into_iter()
-            .map(|(k, s)| (k, s.into_iter()))
-            .collect::<BTreeMap<K, _>>();
-        let mut scanned_spks = BTreeMap::<(K, u32), (ScriptBuf, bool)>::new();
-
-        let (electrum_update, keychain_update) = loop {
-            let (tip, _) = construct_update_tip(self, prev_tip.clone())?;
-            let mut relevant_txids = RelevantTxids::default();
-            let cps = tip
-                .iter()
-                .take(10)
-                .map(|cp| (cp.height(), cp))
-                .collect::<BTreeMap<u32, CheckPoint>>();
-
-            if !request_spks.is_empty() {
-                if !scanned_spks.is_empty() {
-                    scanned_spks.append(&mut populate_with_spks(
-                        self,
-                        &cps,
-                        &mut relevant_txids,
-                        &mut scanned_spks
-                            .iter()
-                            .map(|(i, (spk, _))| (i.clone(), spk.clone())),
-                        stop_gap,
-                        batch_size,
-                    )?);
-                }
-                for (keychain, keychain_spks) in &mut request_spks {
-                    scanned_spks.extend(
-                        populate_with_spks(
-                            self,
-                            &cps,
-                            &mut relevant_txids,
-                            keychain_spks,
-                            stop_gap,
-                            batch_size,
-                        )?
-                        .into_iter()
-                        .map(|(spk_i, spk)| ((keychain.clone(), spk_i), spk)),
-                    );
-                }
-            }
-
-            // check for reorgs during scan process
-            let server_blockhash = self.block_header(tip.height() as usize)?.block_hash();
-            if tip.hash() != server_blockhash {
-                continue; // reorg
-            }
-
-            let chain_update = local_chain::Update {
-                tip,
-                introduce_older_blocks: true,
-            };
-
-            let keychain_update = request_spks
-                .into_keys()
-                .filter_map(|k| {
-                    scanned_spks
-                        .range((k.clone(), u32::MIN)..=(k.clone(), u32::MAX))
-                        .rev()
-                        .find(|(_, (_, active))| *active)
-                        .map(|((_, i), _)| (k, *i))
-                })
-                .collect::<BTreeMap<_, _>>();
-
-            break (
-                ElectrumUpdate {
-                    chain_update,
-                    relevant_txids,
-                },
-                keychain_update,
-            );
-        };
-
-        Ok((electrum_update, keychain_update))
-    }
-
-    fn sync(
-        &self,
-        prev_tip: CheckPoint,
-        misc_spks: impl IntoIterator<Item = ScriptBuf>,
-        txids: impl IntoIterator<Item = Txid>,
-        outpoints: impl IntoIterator<Item = OutPoint>,
-        batch_size: usize,
-    ) -> Result<ElectrumUpdate, Error> {
-        let spk_iter = misc_spks
-            .into_iter()
-            .enumerate()
-            .map(|(i, spk)| (i as u32, spk));
-
-        let (mut electrum_update, _) = self.full_scan(
-            prev_tip.clone(),
-            [((), spk_iter)].into(),
-            usize::MAX,
-            batch_size,
-        )?;
-
-        let (tip, _) = construct_update_tip(self, prev_tip)?;
-        let cps = tip
-            .iter()
-            .take(10)
-            .map(|cp| (cp.height(), cp))
-            .collect::<BTreeMap<u32, CheckPoint>>();
-
-        populate_with_txids(self, &cps, &mut electrum_update.relevant_txids, txids)?;
-
-        let _txs =
-            populate_with_outpoints(self, &cps, &mut electrum_update.relevant_txids, outpoints)?;
-
-        Ok(electrum_update)
-    }
-}
-
-/// Return a [`CheckPoint`] of the latest tip, that connects with `prev_tip`.
-fn construct_update_tip(
-    client: &impl ElectrumApi,
-    prev_tip: CheckPoint,
-) -> Result<(CheckPoint, Option<u32>), Error> {
-    let HeaderNotification { height, .. } = client.block_headers_subscribe()?;
-    let new_tip_height = height as u32;
-
-    // If electrum returns a tip height that is lower than our previous tip, then checkpoints do
-    // not need updating. We just return the previous tip and use that as the point of agreement.
-    if new_tip_height < prev_tip.height() {
-        return Ok((prev_tip.clone(), Some(prev_tip.height())));
-    }
-
-    // Atomically fetch the latest `CHAIN_SUFFIX_LENGTH` count of blocks from Electrum. We use this
-    // to construct our checkpoint update.
-    let mut new_blocks = {
-        let start_height = new_tip_height.saturating_sub(CHAIN_SUFFIX_LENGTH - 1);
-        let hashes = client
-            .block_headers(start_height as _, CHAIN_SUFFIX_LENGTH as _)?
-            .headers
-            .into_iter()
-            .map(|h| h.block_hash());
-        (start_height..).zip(hashes).collect::<BTreeMap<u32, _>>()
-    };
-
-    // Find the "point of agreement" (if any).
-    let agreement_cp = {
-        let mut agreement_cp = Option::<CheckPoint>::None;
-        for cp in prev_tip.iter() {
-            let cp_block = cp.block_id();
-            let hash = match new_blocks.get(&cp_block.height) {
-                Some(&hash) => hash,
-                None => {
-                    assert!(
-                        new_tip_height >= cp_block.height,
-                        "already checked that electrum's tip cannot be smaller"
-                    );
-                    let hash = client.block_header(cp_block.height as _)?.block_hash();
-                    new_blocks.insert(cp_block.height, hash);
-                    hash
-                }
-            };
-            if hash == cp_block.hash {
-                agreement_cp = Some(cp);
-                break;
-            }
-        }
-        agreement_cp
-    };
-
-    let agreement_height = agreement_cp.as_ref().map(CheckPoint::height);
-
-    let new_tip = new_blocks
-        .into_iter()
-        // Prune `new_blocks` to only include blocks that are actually new.
-        .filter(|(height, _)| Some(*height) > agreement_height)
-        .map(|(height, hash)| BlockId { height, hash })
-        .fold(agreement_cp, |prev_cp, block| {
-            Some(match prev_cp {
-                Some(cp) => cp.push(block).expect("must extend checkpoint"),
-                None => CheckPoint::new(block),
-            })
-        })
-        .expect("must have at least one checkpoint");
-
-    Ok((new_tip, agreement_height))
-}
-
-/// A [tx status] comprises of a concatenation of `tx_hash:height:`s. We transform a single one of
-/// these concatenations into a [`ConfirmationHeightAnchor`] if possible.
-///
-/// We use the lowest possible checkpoint as the anchor block (from `cps`). If an anchor block
-/// cannot be found, or the transaction is unconfirmed, [`None`] is returned.
-///
-/// [tx status](https://electrumx-spesmilo.readthedocs.io/en/latest/protocol-basics.html#status)
-fn determine_tx_anchor(
-    cps: &BTreeMap<u32, CheckPoint>,
-    raw_height: i32,
-    txid: Txid,
-) -> Option<ConfirmationHeightAnchor> {
-    // The electrum API has a weird quirk where an unconfirmed transaction is presented with a
-    // height of 0. To avoid invalid representation in our data structures, we manually set
-    // transactions residing in the genesis block to have height 0, then interpret a height of 0 as
-    // unconfirmed for all other transactions.
-    if txid
-        == Txid::from_str("4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b")
-            .expect("must deserialize genesis coinbase txid")
-    {
-        let anchor_block = cps.values().next()?.block_id();
-        return Some(ConfirmationHeightAnchor {
-            anchor_block,
-            confirmation_height: 0,
-        });
-    }
-    match raw_height {
-        h if h <= 0 => {
-            debug_assert!(h == 0 || h == -1, "unexpected height ({}) from electrum", h);
-            None
-        }
-        h => {
-            let h = h as u32;
-            let anchor_block = cps.range(h..).next().map(|(_, cp)| cp.block_id())?;
-            if h > anchor_block.height {
-                None
-            } else {
-                Some(ConfirmationHeightAnchor {
-                    anchor_block,
-                    confirmation_height: h,
-                })
-            }
-        }
-    }
-}
-
-fn populate_with_outpoints(
-    client: &impl ElectrumApi,
-    cps: &BTreeMap<u32, CheckPoint>,
-    relevant_txids: &mut RelevantTxids,
-    outpoints: impl IntoIterator<Item = OutPoint>,
-) -> Result<HashMap<Txid, Transaction>, Error> {
-    let mut full_txs = HashMap::new();
-    for outpoint in outpoints {
-        let txid = outpoint.txid;
-        let tx = client.transaction_get(&txid)?;
-        debug_assert_eq!(tx.txid(), txid);
-        let txout = match tx.output.get(outpoint.vout as usize) {
-            Some(txout) => txout,
-            None => continue,
-        };
-        // attempt to find the following transactions (alongside their chain positions), and
-        // add to our sparsechain `update`:
-        let mut has_residing = false; // tx in which the outpoint resides
-        let mut has_spending = false; // tx that spends the outpoint
-        for res in client.script_get_history(&txout.script_pubkey)? {
-            if has_residing && has_spending {
-                break;
-            }
-
-            if res.tx_hash == txid {
-                if has_residing {
-                    continue;
-                }
-                has_residing = true;
-                full_txs.insert(res.tx_hash, tx.clone());
-            } else {
-                if has_spending {
-                    continue;
-                }
-                let res_tx = match full_txs.get(&res.tx_hash) {
-                    Some(tx) => tx,
-                    None => {
-                        let res_tx = client.transaction_get(&res.tx_hash)?;
-                        full_txs.insert(res.tx_hash, res_tx);
-                        full_txs.get(&res.tx_hash).expect("just inserted")
-                    }
-                };
-                has_spending = res_tx
-                    .input
-                    .iter()
-                    .any(|txin| txin.previous_output == outpoint);
-                if !has_spending {
-                    continue;
-                }
-            };
-
-            let anchor = determine_tx_anchor(cps, res.height, res.tx_hash);
-            let tx_entry = relevant_txids.0.entry(res.tx_hash).or_default();
-            if let Some(anchor) = anchor {
-                tx_entry.insert(anchor);
-            }
-        }
-    }
-    Ok(full_txs)
-}
-
-fn populate_with_txids(
-    client: &impl ElectrumApi,
-    cps: &BTreeMap<u32, CheckPoint>,
-    relevant_txids: &mut RelevantTxids,
-    txids: impl IntoIterator<Item = Txid>,
-) -> Result<(), Error> {
-    for txid in txids {
-        let tx = match client.transaction_get(&txid) {
-            Ok(tx) => tx,
-            Err(electrum_client::Error::Protocol(_)) => continue,
-            Err(other_err) => return Err(other_err),
-        };
-
-        let spk = tx
-            .output
-            .first()
-            .map(|txo| &txo.script_pubkey)
-            .expect("tx must have an output");
-
-        let anchor = match client
-            .script_get_history(spk)?
-            .into_iter()
-            .find(|r| r.tx_hash == txid)
-        {
-            Some(r) => determine_tx_anchor(cps, r.height, txid),
-            None => continue,
-        };
-
-        let tx_entry = relevant_txids.0.entry(txid).or_default();
-        if let Some(anchor) = anchor {
-            tx_entry.insert(anchor);
-        }
-    }
-    Ok(())
-}
-
-fn populate_with_spks<I: Ord + Clone>(
-    client: &impl ElectrumApi,
-    cps: &BTreeMap<u32, CheckPoint>,
-    relevant_txids: &mut RelevantTxids,
-    spks: &mut impl Iterator<Item = (I, ScriptBuf)>,
-    stop_gap: usize,
-    batch_size: usize,
-) -> Result<BTreeMap<I, (ScriptBuf, bool)>, Error> {
-    let mut unused_spk_count = 0_usize;
-    let mut scanned_spks = BTreeMap::new();
-
-    loop {
-        let spks = (0..batch_size)
-            .map_while(|_| spks.next())
-            .collect::<Vec<_>>();
-        if spks.is_empty() {
-            return Ok(scanned_spks);
-        }
-
-        let spk_histories =
-            client.batch_script_get_history(spks.iter().map(|(_, s)| s.as_script()))?;
-
-        for ((spk_index, spk), spk_history) in spks.into_iter().zip(spk_histories) {
-            if spk_history.is_empty() {
-                scanned_spks.insert(spk_index, (spk, false));
-                unused_spk_count += 1;
-                if unused_spk_count > stop_gap {
-                    return Ok(scanned_spks);
-                }
-                continue;
-            } else {
-                scanned_spks.insert(spk_index, (spk, true));
-                unused_spk_count = 0;
-            }
-
-            for tx in spk_history {
-                let tx_entry = relevant_txids.0.entry(tx.tx_hash).or_default();
-                if let Some(anchor) = determine_tx_anchor(cps, tx.height, tx.tx_hash) {
-                    tx_entry.insert(anchor);
-                }
-            }
-        }
-    }
-}
--- a/crates/electrum/src/lib.rs
+++ b/crates/electrum/src/lib.rs
@@ -1,30 +1,588 @@
-//! This crate is used for updating structures of [`bdk_chain`] with data from an Electrum server.
+//! This crate is used for updating structures of the [`bdk_chain`] crate with data from electrum.
 //!
-//! The two primary methods are [`ElectrumExt::sync`] and [`ElectrumExt::full_scan`]. In most cases
-//! [`ElectrumExt::sync`] is used to sync the transaction histories of scripts that the application
-//! cares about, for example the scripts for all the receive addresses of a Wallet's keychain that it
-//! has shown a user. [`ElectrumExt::full_scan`] is meant to be used when importing or restoring a
-//! keychain where the range of possibly used scripts is not known. In this case it is necessary to
-//! scan all keychain scripts until a number (the "stop gap") of unused scripts is discovered. For a
-//! sync or full scan the user receives relevant blockchain data and output updates for
-//! [`bdk_chain`] including [`RelevantTxids`].
+//! The star of the show is the [`ElectrumExt::scan`] method, which scans for relevant blockchain
+//! data (via electrum) and outputs an [`ElectrumUpdate`].
 //!
-//! The [`RelevantTxids`] only includes `txid`s and not full transactions. The caller is responsible
-//! for obtaining full transactions before applying new data to their [`bdk_chain`]. This can be
-//! done with these steps:
+//! An [`ElectrumUpdate`] only includes `txid`s and no full transactions. The caller is responsible
+//! for obtaining full transactions before applying. This can be done with
+//! these steps:
 //!
-//! 1. Determine which full transactions are missing. Use [`RelevantTxids::missing_full_txs`].
+//! 1. Determine which full transactions are missing. The method [`missing_full_txs`] of
+//! [`ElectrumUpdate`] can be used.
 //!
-//! 2. Obtaining the full transactions. To do this via electrum use [`ElectrumApi::batch_transaction_get`].
+//! 2. Obtaining the full transactions. To do this via electrum, the method
+//! [`batch_transaction_get`] can be used.
 //!
-//! Refer to [`example_electrum`] for a complete example.
+//! Refer to [`bdk_electrum_example`] for a complete example.
 //!
-//! [`ElectrumApi::batch_transaction_get`]: electrum_client::ElectrumApi::batch_transaction_get
-//! [`example_electrum`]: https://github.com/bitcoindevkit/bdk/tree/master/example-crates/example_electrum
+//! [`ElectrumClient::scan`]: ElectrumClient::scan
+//! [`missing_full_txs`]: ElectrumUpdate::missing_full_txs
+//! [`batch_transaction_get`]: ElectrumApi::batch_transaction_get
+//! [`bdk_electrum_example`]: https://github.com/LLFourn/bdk_core_staging/tree/master/bdk_electrum_example

-#![warn(missing_docs)]
+use std::{
+    collections::{BTreeMap, HashMap},
+    fmt::Debug,
+};

-mod electrum_ext;
 pub use bdk_chain;
+use bdk_chain::{
+    bitcoin::{hashes::hex::FromHex, BlockHash, OutPoint, Script, Transaction, Txid},
+    chain_graph::{self, ChainGraph},
+    keychain::KeychainScan,
+    sparse_chain::{self, ChainPosition, SparseChain},
+    tx_graph::TxGraph,
+    BlockId, ConfirmationTime, TxHeight,
+};
 pub use electrum_client;
-pub use electrum_ext::*;
+use electrum_client::{Client, ElectrumApi, Error};
+
+/// Trait to extend [`electrum_client::Client`] functionality.
+///
+/// Refer to [crate-level documentation] for more.
+///
+/// [crate-level documentation]: crate
+pub trait ElectrumExt {
+    /// Fetch the latest block height.
+    fn get_tip(&self) -> Result<(u32, BlockHash), Error>;
+
+    /// Scan the blockchain (via electrum) for the data specified. This returns a [`ElectrumUpdate`]
+    /// which can be transformed into a [`KeychainScan`] after we find all the missing full
+    /// transactions.
+    ///
+    /// - `local_chain`: the most recent block hashes present locally
+    /// - `keychain_spks`: keychains that we want to scan transactions for
+    /// - `txids`: transactions for which we want the updated [`ChainPosition`]s
+    /// - `outpoints`: transactions associated with these outpoints (residing, spending) that we
+    ///     want to included in the update
+    fn scan<K: Ord + Clone>(
+        &self,
+        local_chain: &BTreeMap<u32, BlockHash>,
+        keychain_spks: BTreeMap<K, impl IntoIterator<Item = (u32, Script)>>,
+        txids: impl IntoIterator<Item = Txid>,
+        outpoints: impl IntoIterator<Item = OutPoint>,
+        stop_gap: usize,
+        batch_size: usize,
+    ) -> Result<ElectrumUpdate<K, TxHeight>, Error>;
+
+    /// Convenience method to call [`scan`] without requiring a keychain.
+    ///
+    /// [`scan`]: ElectrumExt::scan
+    fn scan_without_keychain(
+        &self,
+        local_chain: &BTreeMap<u32, BlockHash>,
+        misc_spks: impl IntoIterator<Item = Script>,
+        txids: impl IntoIterator<Item = Txid>,
+        outpoints: impl IntoIterator<Item = OutPoint>,
+        batch_size: usize,
+    ) -> Result<SparseChain, Error> {
+        let spk_iter = misc_spks
+            .into_iter()
+            .enumerate()
+            .map(|(i, spk)| (i as u32, spk));
+
+        self.scan(
+            local_chain,
+            [((), spk_iter)].into(),
+            txids,
+            outpoints,
+            usize::MAX,
+            batch_size,
+        )
+        .map(|u| u.chain_update)
+    }
+}
+
+impl ElectrumExt for Client {
+    fn get_tip(&self) -> Result<(u32, BlockHash), Error> {
+        // TODO: unsubscribe when added to the client, or is there a better call to use here?
+        self.block_headers_subscribe()
+            .map(|data| (data.height as u32, data.header.block_hash()))
+    }
+
+    fn scan<K: Ord + Clone>(
+        &self,
+        local_chain: &BTreeMap<u32, BlockHash>,
+        keychain_spks: BTreeMap<K, impl IntoIterator<Item = (u32, Script)>>,
+        txids: impl IntoIterator<Item = Txid>,
+        outpoints: impl IntoIterator<Item = OutPoint>,
+        stop_gap: usize,
+        batch_size: usize,
+    ) -> Result<ElectrumUpdate<K, TxHeight>, Error> {
+        let mut request_spks = keychain_spks
+            .into_iter()
+            .map(|(k, s)| {
+                let iter = s.into_iter();
+                (k, iter)
+            })
+            .collect::<BTreeMap<K, _>>();
+        let mut scanned_spks = BTreeMap::<(K, u32), (Script, bool)>::new();
+
+        let txids = txids.into_iter().collect::<Vec<_>>();
+        let outpoints = outpoints.into_iter().collect::<Vec<_>>();
+
+        let update = loop {
+            let mut update = prepare_update(self, local_chain)?;
+
+            if !request_spks.is_empty() {
+                if !scanned_spks.is_empty() {
+                    let mut scanned_spk_iter = scanned_spks
+                        .iter()
+                        .map(|(i, (spk, _))| (i.clone(), spk.clone()));
+                    match populate_with_spks::<K, _, _>(
+                        self,
+                        &mut update,
+                        &mut scanned_spk_iter,
+                        stop_gap,
+                        batch_size,
+                    ) {
+                        Err(InternalError::Reorg) => continue,
+                        Err(InternalError::ElectrumError(e)) => return Err(e),
+                        Ok(mut spks) => scanned_spks.append(&mut spks),
+                    };
+                }
+                for (keychain, keychain_spks) in &mut request_spks {
+                    match populate_with_spks::<K, u32, _>(
+                        self,
+                        &mut update,
+                        keychain_spks,
+                        stop_gap,
+                        batch_size,
+                    ) {
+                        Err(InternalError::Reorg) => continue,
+                        Err(InternalError::ElectrumError(e)) => return Err(e),
+                        Ok(spks) => scanned_spks.extend(
+                            spks.into_iter()
+                                .map(|(spk_i, spk)| ((keychain.clone(), spk_i), spk)),
+                        ),
+                    };
+                }
+            }
+
+            match populate_with_txids(self, &mut update, &mut txids.iter().cloned()) {
+                Err(InternalError::Reorg) => continue,
+                Err(InternalError::ElectrumError(e)) => return Err(e),
+                Ok(_) => {}
+            }
+
+            match populate_with_outpoints(self, &mut update, &mut outpoints.iter().cloned()) {
+                Err(InternalError::Reorg) => continue,
+                Err(InternalError::ElectrumError(e)) => return Err(e),
+                Ok(_txs) => { /* [TODO] cache full txs to reduce bandwidth */ }
+            }
+
+            // check for reorgs during scan process
+            let our_tip = update
+                .latest_checkpoint()
+                .expect("update must have atleast one checkpoint");
+            let server_blockhash = self.block_header(our_tip.height as usize)?.block_hash();
+            if our_tip.hash != server_blockhash {
+                continue; // reorg
+            } else {
+                break update;
+            }
+        };
+
+        let last_active_index = request_spks
+            .into_keys()
+            .filter_map(|k| {
+                scanned_spks
+                    .range((k.clone(), u32::MIN)..=(k.clone(), u32::MAX))
+                    .rev()
+                    .find(|(_, (_, active))| *active)
+                    .map(|((_, i), _)| (k, *i))
+            })
+            .collect::<BTreeMap<_, _>>();
+
+        Ok(ElectrumUpdate {
+            chain_update: update,
+            last_active_indices: last_active_index,
+        })
+    }
+}
+
+/// The result of [`ElectrumExt::scan`].
+pub struct ElectrumUpdate<K, P> {
+    /// The internal [`SparseChain`] update.
+    pub chain_update: SparseChain<P>,
+    /// The last keychain script pubkey indices, which had transaction histories.
+    pub last_active_indices: BTreeMap<K, u32>,
+}
+
+impl<K, P> Default for ElectrumUpdate<K, P> {
+    fn default() -> Self {
+        Self {
+            chain_update: Default::default(),
+            last_active_indices: Default::default(),
+        }
+    }
+}
+
+impl<K, P> AsRef<SparseChain<P>> for ElectrumUpdate<K, P> {
+    fn as_ref(&self) -> &SparseChain<P> {
+        &self.chain_update
+    }
+}
+
+impl<K: Ord + Clone + Debug, P: ChainPosition> ElectrumUpdate<K, P> {
+    /// Return a list of missing full transactions that are required to [`inflate_update`].
+    ///
+    /// [`inflate_update`]: bdk_chain::chain_graph::ChainGraph::inflate_update
+    pub fn missing_full_txs<G>(&self, graph: G) -> Vec<&Txid>
+    where
+        G: AsRef<TxGraph>,
+    {
+        self.chain_update
+            .txids()
+            .filter(|(_, txid)| graph.as_ref().get_tx(*txid).is_none())
+            .map(|(_, txid)| txid)
+            .collect()
+    }
+
+    /// Transform the [`ElectrumUpdate`] into a [`KeychainScan`], which can be applied to a
+    /// `tracker`.
+    ///
+    /// This will fail if there are missing full transactions not provided via `new_txs`.
+    pub fn into_keychain_scan<CG>(
+        self,
+        new_txs: Vec<Transaction>,
+        chain_graph: &CG,
+    ) -> Result<KeychainScan<K, P>, chain_graph::NewError<P>>
+    where
+        CG: AsRef<ChainGraph<P>>,
+    {
+        Ok(KeychainScan {
+            update: chain_graph
+                .as_ref()
+                .inflate_update(self.chain_update, new_txs)?,
+            last_active_indices: self.last_active_indices,
+        })
+    }
+}
+
+impl<K: Ord + Clone + Debug> ElectrumUpdate<K, TxHeight> {
+    /// Creates [`ElectrumUpdate<K, ConfirmationTime>`] from [`ElectrumUpdate<K, TxHeight>`].
+    pub fn into_confirmation_time_update(
+        self,
+        client: &electrum_client::Client,
+    ) -> Result<ElectrumUpdate<K, ConfirmationTime>, Error> {
+        let heights = self
+            .chain_update
+            .range_txids_by_height(..TxHeight::Unconfirmed)
+            .map(|(h, _)| match h {
+                TxHeight::Confirmed(h) => *h,
+                _ => unreachable!("already filtered out unconfirmed"),
+            })
+            .collect::<Vec<u32>>();
+
+        let height_to_time = heights
+            .clone()
+            .into_iter()
+            .zip(
+                client
+                    .batch_block_header(heights)?
+                    .into_iter()
+                    .map(|bh| bh.time as u64),
+            )
+            .collect::<HashMap<u32, u64>>();
+
+        let mut new_update = SparseChain::<ConfirmationTime>::from_checkpoints(
+            self.chain_update.range_checkpoints(..),
+        );
+
+        for &(tx_height, txid) in self.chain_update.txids() {
+            let conf_time = match tx_height {
+                TxHeight::Confirmed(height) => ConfirmationTime::Confirmed {
+                    height,
+                    time: height_to_time[&height],
+                },
+                TxHeight::Unconfirmed => ConfirmationTime::Unconfirmed,
+            };
+            let _ = new_update.insert_tx(txid, conf_time).expect("must insert");
+        }
+
+        Ok(ElectrumUpdate {
+            chain_update: new_update,
+            last_active_indices: self.last_active_indices,
+        })
+    }
+}
+
+#[derive(Debug)]
+enum InternalError {
+    ElectrumError(Error),
+    Reorg,
+}
+
+impl From<electrum_client::Error> for InternalError {
+    fn from(value: electrum_client::Error) -> Self {
+        Self::ElectrumError(value)
+    }
+}
+
+fn get_tip(client: &Client) -> Result<(u32, BlockHash), Error> {
+    // TODO: unsubscribe when added to the client, or is there a better call to use here?
+    client
+        .block_headers_subscribe()
+        .map(|data| (data.height as u32, data.header.block_hash()))
+}
+
+/// Prepare an update sparsechain "template" based on the checkpoints of the `local_chain`.
+fn prepare_update(
+    client: &Client,
+    local_chain: &BTreeMap<u32, BlockHash>,
+) -> Result<SparseChain, Error> {
+    let mut update = SparseChain::default();
+
+    // Find the local chain block that is still there so our update can connect to the local chain.
+    for (&existing_height, &existing_hash) in local_chain.iter().rev() {
+        // TODO: a batch request may be safer, as a reorg that happens when we are obtaining
+        //       `block_header`s will result in inconsistencies
+        let current_hash = client.block_header(existing_height as usize)?.block_hash();
+        let _ = update
+            .insert_checkpoint(BlockId {
+                height: existing_height,
+                hash: current_hash,
+            })
+            .expect("This never errors because we are working with a fresh chain");
+
+        if current_hash == existing_hash {
+            break;
+        }
+    }
+
+    // Insert the new tip so new transactions will be accepted into the sparsechain.
+    let tip = {
+        let (height, hash) = get_tip(client)?;
+        BlockId { height, hash }
+    };
+    if let Err(failure) = update.insert_checkpoint(tip) {
+        match failure {
+            sparse_chain::InsertCheckpointError::HashNotMatching { .. } => {
+                // There has been a re-org before we even begin scanning addresses.
+                // Just recursively call (this should never happen).
+                return prepare_update(client, local_chain);
+            }
+        }
+    }
+
+    Ok(update)
+}
+
+/// This atrocity is required because electrum thinks a height of 0 means "unconfirmed", but there is
+/// such thing as a genesis block.
+///
+/// We contain an expectation for the genesis coinbase txid to always have a chain position of
+/// [`TxHeight::Confirmed(0)`].
+fn determine_tx_height(raw_height: i32, tip_height: u32, txid: Txid) -> TxHeight {
+    if txid
+        == Txid::from_hex("4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b")
+            .expect("must deserialize genesis coinbase txid")
+    {
+        return TxHeight::Confirmed(0);
+    }
+    match raw_height {
+        h if h <= 0 => {
+            debug_assert!(
+                h == 0 || h == -1,
+                "unexpected height ({}) from electrum server",
+                h
+            );
+            TxHeight::Unconfirmed
+        }
+        h => {
+            let h = h as u32;
+            if h > tip_height {
+                TxHeight::Unconfirmed
+            } else {
+                TxHeight::Confirmed(h)
+            }
+        }
+    }
+}
+
+/// Populates the update [`SparseChain`] with related transactions and associated [`ChainPosition`]s
+/// of the provided `outpoints` (this is the tx which contains the outpoint and the one spending the
+/// outpoint).
+///
+/// Unfortunately, this is awkward to implement as electrum does not provide such an API. Instead, we
+/// will get the tx history of the outpoint's spk and try to find the containing tx and the
+/// spending tx.
+fn populate_with_outpoints(
+    client: &Client,
+    update: &mut SparseChain,
+    outpoints: &mut impl Iterator<Item = OutPoint>,
+) -> Result<HashMap<Txid, Transaction>, InternalError> {
+    let tip = update
+        .latest_checkpoint()
+        .expect("update must atleast have one checkpoint");
+
+    let mut full_txs = HashMap::new();
+    for outpoint in outpoints {
+        let txid = outpoint.txid;
+        let tx = client.transaction_get(&txid)?;
+        debug_assert_eq!(tx.txid(), txid);
+        let txout = match tx.output.get(outpoint.vout as usize) {
+            Some(txout) => txout,
+            None => continue,
+        };
+
+        // attempt to find the following transactions (alongside their chain positions), and
+        // add to our sparsechain `update`:
+        let mut has_residing = false; // tx in which the outpoint resides
+        let mut has_spending = false; // tx that spends the outpoint
+        for res in client.script_get_history(&txout.script_pubkey)? {
+            if has_residing && has_spending {
+                break;
+            }
+
+            if res.tx_hash == txid {
+                if has_residing {
+                    continue;
+                }
+                has_residing = true;
+                full_txs.insert(res.tx_hash, tx.clone());
+            } else {
+                if has_spending {
+                    continue;
+                }
+                let res_tx = match full_txs.get(&res.tx_hash) {
+                    Some(tx) => tx,
+                    None => {
+                        let res_tx = client.transaction_get(&res.tx_hash)?;
+                        full_txs.insert(res.tx_hash, res_tx);
+                        full_txs.get(&res.tx_hash).expect("just inserted")
+                    }
+                };
+                has_spending = res_tx
+                    .input
+                    .iter()
+                    .any(|txin| txin.previous_output == outpoint);
+                if !has_spending {
+                    continue;
+                }
+            };
+
+            let tx_height = determine_tx_height(res.height, tip.height, res.tx_hash);
+
+            if let Err(failure) = update.insert_tx(res.tx_hash, tx_height) {
+                match failure {
+                    sparse_chain::InsertTxError::TxTooHigh { .. } => {
+                        unreachable!("we should never encounter this as we ensured height <= tip");
+                    }
+                    sparse_chain::InsertTxError::TxMovedUnexpectedly { .. } => {
+                        return Err(InternalError::Reorg);
+                    }
+                }
+            }
+        }
+    }
+    Ok(full_txs)
+}
+
+/// Populate an update [`SparseChain`] with transactions (and associated block positions) from
+/// the given `txids`.
+fn populate_with_txids(
+    client: &Client,
+    update: &mut SparseChain,
+    txids: &mut impl Iterator<Item = Txid>,
+) -> Result<(), InternalError> {
+    let tip = update
+        .latest_checkpoint()
+        .expect("update must have atleast one checkpoint");
+    for txid in txids {
+        let tx = match client.transaction_get(&txid) {
+            Ok(tx) => tx,
+            Err(electrum_client::Error::Protocol(_)) => continue,
+            Err(other_err) => return Err(other_err.into()),
+        };
+
+        let spk = tx
+            .output
+            .get(0)
+            .map(|txo| &txo.script_pubkey)
+            .expect("tx must have an output");
+
+        let tx_height = match client
+            .script_get_history(spk)?
+            .into_iter()
+            .find(|r| r.tx_hash == txid)
+        {
+            Some(r) => determine_tx_height(r.height, tip.height, r.tx_hash),
+            None => continue,
+        };
+
+        if let Err(failure) = update.insert_tx(txid, tx_height) {
+            match failure {
+                sparse_chain::InsertTxError::TxTooHigh { .. } => {
+                    unreachable!("we should never encounter this as we ensured height <= tip");
+                }
+                sparse_chain::InsertTxError::TxMovedUnexpectedly { .. } => {
+                    return Err(InternalError::Reorg);
+                }
+            }
+        }
+    }
+    Ok(())
+}
+
+/// Populate an update [`SparseChain`] with transactions (and associated block positions) from
+/// the transaction history of the provided `spk`s.
+fn populate_with_spks<K, I, S>(
+    client: &Client,
+    update: &mut SparseChain,
+    spks: &mut S,
+    stop_gap: usize,
+    batch_size: usize,
+) -> Result<BTreeMap<I, (Script, bool)>, InternalError>
+where
+    K: Ord + Clone,
+    I: Ord + Clone,
+    S: Iterator<Item = (I, Script)>,
+{
+    let tip = update.latest_checkpoint().map_or(0, |cp| cp.height);
+    let mut unused_spk_count = 0_usize;
+    let mut scanned_spks = BTreeMap::new();
+
+    loop {
+        let spks = (0..batch_size)
+            .map_while(|_| spks.next())
+            .collect::<Vec<_>>();
+        if spks.is_empty() {
+            return Ok(scanned_spks);
+        }
+
+        let spk_histories = client.batch_script_get_history(spks.iter().map(|(_, s)| s))?;
+
+        for ((spk_index, spk), spk_history) in spks.into_iter().zip(spk_histories) {
+            if spk_history.is_empty() {
+                scanned_spks.insert(spk_index, (spk, false));
+                unused_spk_count += 1;
+                if unused_spk_count > stop_gap {
+                    return Ok(scanned_spks);
+                }
+                continue;
+            } else {
+                scanned_spks.insert(spk_index, (spk, true));
+                unused_spk_count = 0;
+            }
+
+            for tx in spk_history {
+                let tx_height = determine_tx_height(tx.height, tip, tx.tx_hash);
+
+                if let Err(failure) = update.insert_tx(tx.tx_hash, tx_height) {
+                    match failure {
+                        sparse_chain::InsertTxError::TxTooHigh { .. } => {
+                            unreachable!(
+                                "we should never encounter this as we ensured height <= tip"
+                            );
+                        }
+                        sparse_chain::InsertTxError::TxMovedUnexpectedly { .. } => {
+                            return Err(InternalError::Reorg);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
--- a/crates/electrum/tests/test_electrum.rs
+++ b/crates/electrum/tests/test_electrum.rs
@@ -1,191 +0,0 @@
-use anyhow::Result;
-use bdk_chain::{
-    bitcoin::{hashes::Hash, Address, Amount, ScriptBuf, WScriptHash},
-    keychain::Balance,
-    local_chain::LocalChain,
-    ConfirmationTimeHeightAnchor, IndexedTxGraph, SpkTxOutIndex,
-};
-use bdk_electrum::{ElectrumExt, ElectrumUpdate};
-use bdk_testenv::TestEnv;
-use electrsd::bitcoind::bitcoincore_rpc::RpcApi;
-
-fn get_balance(
-    recv_chain: &LocalChain,
-    recv_graph: &IndexedTxGraph<ConfirmationTimeHeightAnchor, SpkTxOutIndex<()>>,
-) -> Result<Balance> {
-    let chain_tip = recv_chain.tip().block_id();
-    let outpoints = recv_graph.index.outpoints().clone();
-    let balance = recv_graph
-        .graph()
-        .balance(recv_chain, chain_tip, outpoints, |_, _| true);
-    Ok(balance)
-}
-
-/// Ensure that [`ElectrumExt`] can sync properly.
-///
-/// 1. Mine 101 blocks.
-/// 2. Send a tx.
-/// 3. Mine extra block to confirm sent tx.
-/// 4. Check [`Balance`] to ensure tx is confirmed.
-#[test]
-fn scan_detects_confirmed_tx() -> Result<()> {
-    const SEND_AMOUNT: Amount = Amount::from_sat(10_000);
-
-    let env = TestEnv::new()?;
-    let client = electrum_client::Client::new(env.electrsd.electrum_url.as_str())?;
-
-    // Setup addresses.
-    let addr_to_mine = env
-        .bitcoind
-        .client
-        .get_new_address(None, None)?
-        .assume_checked();
-    let spk_to_track = ScriptBuf::new_p2wsh(&WScriptHash::all_zeros());
-    let addr_to_track = Address::from_script(&spk_to_track, bdk_chain::bitcoin::Network::Regtest)?;
-
-    // Setup receiver.
-    let (mut recv_chain, _) = LocalChain::from_genesis_hash(env.bitcoind.client.get_block_hash(0)?);
-    let mut recv_graph = IndexedTxGraph::<ConfirmationTimeHeightAnchor, _>::new({
-        let mut recv_index = SpkTxOutIndex::default();
-        recv_index.insert_spk((), spk_to_track.clone());
-        recv_index
-    });
-
-    // Mine some blocks.
-    env.mine_blocks(101, Some(addr_to_mine))?;
-
-    // Create transaction that is tracked by our receiver.
-    env.send(&addr_to_track, SEND_AMOUNT)?;
-
-    // Mine a block to confirm sent tx.
-    env.mine_blocks(1, None)?;
-
-    // Sync up to tip.
-    env.wait_until_electrum_sees_block()?;
-    let ElectrumUpdate {
-        chain_update,
-        relevant_txids,
-    } = client.sync(recv_chain.tip(), [spk_to_track], None, None, 5)?;
-
-    let missing = relevant_txids.missing_full_txs(recv_graph.graph());
-    let graph_update = relevant_txids.into_confirmation_time_tx_graph(&client, missing)?;
-    let _ = recv_chain
-        .apply_update(chain_update)
-        .map_err(|err| anyhow::anyhow!("LocalChain update error: {:?}", err))?;
-    let _ = recv_graph.apply_update(graph_update);
-
-    // Check to see if tx is confirmed.
-    assert_eq!(
-        get_balance(&recv_chain, &recv_graph)?,
-        Balance {
-            confirmed: SEND_AMOUNT.to_sat(),
-            ..Balance::default()
-        },
-    );
-
-    Ok(())
-}
-
-/// Ensure that confirmed txs that are reorged become unconfirmed.
-///
-/// 1. Mine 101 blocks.
-/// 2. Mine 8 blocks with a confirmed tx in each.
-/// 3. Perform 8 separate reorgs on each block with a confirmed tx.
-/// 4. Check [`Balance`] after each reorg to ensure unconfirmed amount is correct.
-#[test]
-fn tx_can_become_unconfirmed_after_reorg() -> Result<()> {
-    const REORG_COUNT: usize = 8;
-    const SEND_AMOUNT: Amount = Amount::from_sat(10_000);
-
-    let env = TestEnv::new()?;
-    let client = electrum_client::Client::new(env.electrsd.electrum_url.as_str())?;
-
-    // Setup addresses.
-    let addr_to_mine = env
-        .bitcoind
-        .client
-        .get_new_address(None, None)?
-        .assume_checked();
-    let spk_to_track = ScriptBuf::new_p2wsh(&WScriptHash::all_zeros());
-    let addr_to_track = Address::from_script(&spk_to_track, bdk_chain::bitcoin::Network::Regtest)?;
-
-    // Setup receiver.
-    let (mut recv_chain, _) = LocalChain::from_genesis_hash(env.bitcoind.client.get_block_hash(0)?);
-    let mut recv_graph = IndexedTxGraph::<ConfirmationTimeHeightAnchor, _>::new({
-        let mut recv_index = SpkTxOutIndex::default();
-        recv_index.insert_spk((), spk_to_track.clone());
-        recv_index
-    });
-
-    // Mine some blocks.
-    env.mine_blocks(101, Some(addr_to_mine))?;
-
-    // Create transactions that are tracked by our receiver.
-    for _ in 0..REORG_COUNT {
-        env.send(&addr_to_track, SEND_AMOUNT)?;
-        env.mine_blocks(1, None)?;
-    }
-
-    // Sync up to tip.
-    env.wait_until_electrum_sees_block()?;
-    let ElectrumUpdate {
-        chain_update,
-        relevant_txids,
-    } = client.sync(recv_chain.tip(), [spk_to_track.clone()], None, None, 5)?;
-
-    let missing = relevant_txids.missing_full_txs(recv_graph.graph());
-    let graph_update = relevant_txids.into_confirmation_time_tx_graph(&client, missing)?;
-    let _ = recv_chain
-        .apply_update(chain_update)
-        .map_err(|err| anyhow::anyhow!("LocalChain update error: {:?}", err))?;
-    let _ = recv_graph.apply_update(graph_update.clone());
-
-    // Retain a snapshot of all anchors before reorg process.
-    let initial_anchors = graph_update.all_anchors();
-
-    // Check if initial balance is correct.
-    assert_eq!(
-        get_balance(&recv_chain, &recv_graph)?,
-        Balance {
-            confirmed: SEND_AMOUNT.to_sat() * REORG_COUNT as u64,
-            ..Balance::default()
-        },
-        "initial balance must be correct",
-    );
-
-    // Perform reorgs with different depths.
-    for depth in 1..=REORG_COUNT {
-        env.reorg_empty_blocks(depth)?;
-
-        env.wait_until_electrum_sees_block()?;
-        let ElectrumUpdate {
-            chain_update,
-            relevant_txids,
-        } = client.sync(recv_chain.tip(), [spk_to_track.clone()], None, None, 5)?;
-
-        let missing = relevant_txids.missing_full_txs(recv_graph.graph());
-        let graph_update = relevant_txids.into_confirmation_time_tx_graph(&client, missing)?;
-        let _ = recv_chain
-            .apply_update(chain_update)
-            .map_err(|err| anyhow::anyhow!("LocalChain update error: {:?}", err))?;
-
-        // Check to see if a new anchor is added during current reorg.
-        if !initial_anchors.is_superset(graph_update.all_anchors()) {
-            println!("New anchor added at reorg depth {}", depth);
-        }
-        let _ = recv_graph.apply_update(graph_update);
-
-        assert_eq!(
-            get_balance(&recv_chain, &recv_graph)?,
-            Balance {
-                confirmed: SEND_AMOUNT.to_sat() * (REORG_COUNT - depth) as u64,
-                trusted_pending: SEND_AMOUNT.to_sat() * depth as u64,
-                ..Balance::default()
-            },
-            "reorg_count: {}",
-            depth,
-        );
-    }
-
-    Ok(())
-}
--- a/crates/esplora/Cargo.toml
+++ b/crates/esplora/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "bdk_esplora"
-version = "0.11.0"
+version = "0.2.0"
 edition = "2021"
 homepage = "https://bitcoindevkit.org"
 repository = "https://github.com/bitcoindevkit/bdk"
@@ -12,24 +12,13 @@ readme = "README.md"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

 [dependencies]
-bdk_chain = { path = "../chain", version = "0.12.0", default-features = false }
-esplora-client = { version = "0.7.0", default-features = false }
+bdk_chain = { path = "../chain", version = "0.4.0", features = ["serde", "miniscript"] }
+esplora-client = { version = "0.3", default-features = false }
 async-trait = { version = "0.1.66", optional = true }
 futures = { version = "0.3.26", optional = true }

-# use these dependencies if you need to enable their /no-std features
-bitcoin = { version = "0.31.0", optional = true, default-features = false }
-miniscript = { version = "11.0.0", optional = true, default-features = false }
-
-[dev-dependencies]
-bdk_testenv = { path = "../testenv", default_features = false }
-electrsd = { version= "0.27.1", features = ["bitcoind_25_0", "esplora_a33e97e1", "legacy"] }
-tokio = { version = "1", features = ["rt", "rt-multi-thread", "macros"] }
-
 [features]
-default = ["std", "async-https", "blocking"]
-std = ["bdk_chain/std"]
+default = ["async-https", "blocking"]
 async = ["async-trait", "futures", "esplora-client/async"]
 async-https = ["async", "esplora-client/async-https"]
-async-https-rustls = ["async", "esplora-client/async-https-rustls"]
 blocking = ["esplora-client/blocking"]
--- a/crates/esplora/README.md
+++ b/crates/esplora/README.md
@@ -1,6 +1,6 @@
 # BDK Esplora

-BDK Esplora extends [`esplora-client`] to update [`bdk_chain`] structures
+BDK Esplora extends [`esplora_client`](crate::esplora_client) to update [`bdk_chain`] structures
 from an Esplora server.

 ## Usage
@@ -9,17 +9,17 @@ There are two versions of the extension trait (blocking and async).

 For blocking-only:
 ```toml
-bdk_esplora = { version = "0.3", features = ["blocking"] }
+bdk_esplora = { version = "0.1", features = ["blocking"] }
 ```

 For async-only:
 ```toml
-bdk_esplora = { version = "0.3", features = ["async"] }
+bdk_esplora = { version = "0.1", features = ["async"] }
 ```

 For async-only (with https):
 ```toml
-bdk_esplora = { version = "0.3", features = ["async-https"] }
+bdk_esplora = { version = "0.1", features = ["async-https"] }
 ```

 To use the extension traits:
@@ -27,10 +27,7 @@ To use the extension traits:
 // for blocking
 use bdk_esplora::EsploraExt;
 // for async
-// use bdk_esplora::EsploraAsyncExt;
+use bdk_esplora::EsploraAsyncExt;
 ```

-For full examples, refer to [`example-crates/wallet_esplora_blocking`](https://github.com/bitcoindevkit/bdk/tree/master/example-crates/wallet_esplora_blocking) and [`example-crates/wallet_esplora_async`](https://github.com/bitcoindevkit/bdk/tree/master/example-crates/wallet_esplora_async).
-
-[`esplora-client`]: https://docs.rs/esplora-client/
-[`bdk_chain`]: https://docs.rs/bdk-chain/
+For full examples, refer to [`example-crates/wallet_esplora`](https://github.com/bitcoindevkit/bdk/tree/master/example-crates/wallet_esplora) (blocking) and [`example-crates/wallet_esplora_async`](https://github.com/bitcoindevkit/bdk/tree/master/example-crates/wallet_esplora_async).
--- a/crates/esplora/src/async_ext.rs
+++ b/crates/esplora/src/async_ext.rs
@@ -1,272 +1,70 @@
+use std::collections::BTreeMap;
+
 use async_trait::async_trait;
-use bdk_chain::collections::btree_map;
 use bdk_chain::{
-    bitcoin::{Amount, BlockHash, OutPoint, ScriptBuf, TxOut, Txid},
-    collections::BTreeMap,
-    local_chain::{self, CheckPoint},
-    BlockId, ConfirmationTimeHeightAnchor, TxGraph,
+    bitcoin::{BlockHash, OutPoint, Script, Txid},
+    chain_graph::ChainGraph,
+    keychain::KeychainScan,
+    sparse_chain, BlockId, ConfirmationTime,
 };
-use esplora_client::TxStatus;
-use futures::{stream::FuturesOrdered, TryStreamExt};
+use esplora_client::{Error, OutputStatus};
+use futures::stream::{FuturesOrdered, TryStreamExt};

-use crate::anchor_from_status;
+use crate::map_confirmation_time;

-/// [`esplora_client::Error`]
-type Error = Box<esplora_client::Error>;
-
-/// Trait to extend the functionality of [`esplora_client::AsyncClient`].
+/// Trait to extend [`esplora_client::AsyncClient`] functionality.
 ///
-/// Refer to [crate-level documentation] for more.
+/// This is the async version of [`EsploraExt`]. Refer to
+/// [crate-level documentation] for more.
 ///
+/// [`EsploraExt`]: crate::EsploraExt
 /// [crate-level documentation]: crate
+#[cfg(feature = "async")]
 #[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
 #[cfg_attr(not(target_arch = "wasm32"), async_trait)]
 pub trait EsploraAsyncExt {
-    /// Prepare a [`LocalChain`] update with blocks fetched from Esplora.
+    /// Scan the blockchain (via esplora) for the data specified and returns a [`KeychainScan`].
    ///
-    /// * `local_tip` is the previous tip of [`LocalChain::tip`].
-    /// * `request_heights` is the block heights that we are interested in fetching from Esplora.
+    /// - `local_chain`: the most recent block hashes present locally
+    /// - `keychain_spks`: keychains that we want to scan transactions for
+    /// - `txids`: transactions for which we want updated [`ChainPosition`]s
+    /// - `outpoints`: transactions associated with these outpoints (residing, spending) that we
+    ///     want to included in the update
    ///
-    /// The result of this method can be applied to [`LocalChain::apply_update`].
-    ///
-    /// ## Consistency
-    ///
-    /// The chain update returned is guaranteed to be consistent as long as there is not a *large* re-org
-    /// during the call. The size of re-org we can tollerate is server dependent but will be at
-    /// least 10.
-    ///
-    /// [`LocalChain`]: bdk_chain::local_chain::LocalChain
-    /// [`LocalChain::tip`]: bdk_chain::local_chain::LocalChain::tip
-    /// [`LocalChain::apply_update`]: bdk_chain::local_chain::LocalChain::apply_update
-    async fn update_local_chain(
-        &self,
-        local_tip: CheckPoint,
-        request_heights: impl IntoIterator<IntoIter = impl Iterator<Item = u32> + Send> + Send,
-    ) -> Result<local_chain::Update, Error>;
-
-    /// Full scan the keychain scripts specified with the blockchain (via an Esplora client) and
-    /// returns a [`TxGraph`] and a map of last active indices.
-    ///
-    /// * `keychain_spks`: keychains that we want to scan transactions for
-    ///
-    /// The full scan for each keychain stops after a gap of `stop_gap` script pubkeys with no associated
+    /// The scan for each keychain stops after a gap of `stop_gap` script pubkeys with no associated
    /// transactions. `parallel_requests` specifies the max number of HTTP requests to make in
    /// parallel.
    ///
-    /// ## Note
-    ///
-    /// `stop_gap` is defined as "the maximum number of consecutive unused addresses".
-    /// For example, with a `stop_gap` of  3, `full_scan` will keep scanning
-    /// until it encounters 3 consecutive script pubkeys with no associated transactions.
-    ///
-    /// This follows the same approach as other Bitcoin-related software,
-    /// such as [Electrum](https://electrum.readthedocs.io/en/latest/faq.html#what-is-the-gap-limit),
-    /// [BTCPay Server](https://docs.btcpayserver.org/FAQ/Wallet/#the-gap-limit-problem),
-    /// and [Sparrow](https://www.sparrowwallet.com/docs/faq.html#ive-restored-my-wallet-but-some-of-my-funds-are-missing).
-    ///
-    /// A `stop_gap` of 0 will be treated as a `stop_gap` of 1.
-    async fn full_scan<K: Ord + Clone + Send>(
+    /// [`ChainPosition`]: bdk_chain::sparse_chain::ChainPosition
+    #[allow(clippy::result_large_err)] // FIXME
+    async fn scan<K: Ord + Clone + Send>(
        &self,
+        local_chain: &BTreeMap<u32, BlockHash>,
        keychain_spks: BTreeMap<
            K,
-            impl IntoIterator<IntoIter = impl Iterator<Item = (u32, ScriptBuf)> + Send> + Send,
+            impl IntoIterator<IntoIter = impl Iterator<Item = (u32, Script)> + Send> + Send,
        >,
+        txids: impl IntoIterator<IntoIter = impl Iterator<Item = Txid> + Send> + Send,
+        outpoints: impl IntoIterator<IntoIter = impl Iterator<Item = OutPoint> + Send> + Send,
        stop_gap: usize,
        parallel_requests: usize,
-    ) -> Result<(TxGraph<ConfirmationTimeHeightAnchor>, BTreeMap<K, u32>), Error>;
+    ) -> Result<KeychainScan<K, ConfirmationTime>, Error>;

-    /// Sync a set of scripts with the blockchain (via an Esplora client) for the data
-    /// specified and return a [`TxGraph`].
+    /// Convenience method to call [`scan`] without requiring a keychain.
    ///
-    /// * `misc_spks`: scripts that we want to sync transactions for
-    /// * `txids`: transactions for which we want updated [`ConfirmationTimeHeightAnchor`]s
-    /// * `outpoints`: transactions associated with these outpoints (residing, spending) that we
-    ///     want to include in the update
-    ///
-    /// If the scripts to sync are unknown, such as when restoring or importing a keychain that
-    /// may include scripts that have been used, use [`full_scan`] with the keychain.
-    ///
-    /// [`full_scan`]: EsploraAsyncExt::full_scan
-    async fn sync(
+    /// [`scan`]: EsploraAsyncExt::scan
+    #[allow(clippy::result_large_err)] // FIXME
+    async fn scan_without_keychain(
        &self,
-        misc_spks: impl IntoIterator<IntoIter = impl Iterator<Item = ScriptBuf> + Send> + Send,
+        local_chain: &BTreeMap<u32, BlockHash>,
+        misc_spks: impl IntoIterator<IntoIter = impl Iterator<Item = Script> + Send> + Send,
        txids: impl IntoIterator<IntoIter = impl Iterator<Item = Txid> + Send> + Send,
        outpoints: impl IntoIterator<IntoIter = impl Iterator<Item = OutPoint> + Send> + Send,
        parallel_requests: usize,
-    ) -> Result<TxGraph<ConfirmationTimeHeightAnchor>, Error>;
-}
-
-#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
-#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
-impl EsploraAsyncExt for esplora_client::AsyncClient {
-    async fn update_local_chain(
-        &self,
-        local_tip: CheckPoint,
-        request_heights: impl IntoIterator<IntoIter = impl Iterator<Item = u32> + Send> + Send,
-    ) -> Result<local_chain::Update, Error> {
-        // Fetch latest N (server dependent) blocks from Esplora. The server guarantees these are
-        // consistent.
-        let mut fetched_blocks = self
-            .get_blocks(None)
-            .await?
-            .into_iter()
-            .map(|b| (b.time.height, b.id))
-            .collect::<BTreeMap<u32, BlockHash>>();
-        let new_tip_height = fetched_blocks
-            .keys()
-            .last()
-            .copied()
-            .expect("must have atleast one block");
-
-        // Fetch blocks of heights that the caller is interested in, skipping blocks that are
-        // already fetched when constructing `fetched_blocks`.
-        for height in request_heights {
-            // do not fetch blocks higher than remote tip
-            if height > new_tip_height {
-                continue;
-            }
-            // only fetch what is missing
-            if let btree_map::Entry::Vacant(entry) = fetched_blocks.entry(height) {
-                // ❗The return value of `get_block_hash` is not strictly guaranteed to be consistent
-                // with the chain at the time of `get_blocks` above (there could have been a deep
-                // re-org). Since `get_blocks` returns 10 (or so) blocks we are assuming that it's
-                // not possible to have a re-org deeper than that.
-                entry.insert(self.get_block_hash(height).await?);
-            }
-        }
-
-        // Ensure `fetched_blocks` can create an update that connects with the original chain by
-        // finding a "Point of Agreement".
-        for (height, local_hash) in local_tip.iter().map(|cp| (cp.height(), cp.hash())) {
-            if height > new_tip_height {
-                continue;
-            }
-
-            let fetched_hash = match fetched_blocks.entry(height) {
-                btree_map::Entry::Occupied(entry) => *entry.get(),
-                btree_map::Entry::Vacant(entry) => {
-                    *entry.insert(self.get_block_hash(height).await?)
-                }
-            };
-
-            // We have found point of agreement so the update will connect!
-            if fetched_hash == local_hash {
-                break;
-            }
-        }
-
-        Ok(local_chain::Update {
-            tip: CheckPoint::from_block_ids(fetched_blocks.into_iter().map(BlockId::from))
-                .expect("must be in height order"),
-            introduce_older_blocks: true,
-        })
-    }
-
-    async fn full_scan<K: Ord + Clone + Send>(
-        &self,
-        keychain_spks: BTreeMap<
-            K,
-            impl IntoIterator<IntoIter = impl Iterator<Item = (u32, ScriptBuf)> + Send> + Send,
-        >,
-        stop_gap: usize,
-        parallel_requests: usize,
-    ) -> Result<(TxGraph<ConfirmationTimeHeightAnchor>, BTreeMap<K, u32>), Error> {
-        type TxsOfSpkIndex = (u32, Vec<esplora_client::Tx>);
-        let parallel_requests = Ord::max(parallel_requests, 1);
-        let mut graph = TxGraph::<ConfirmationTimeHeightAnchor>::default();
-        let mut last_active_indexes = BTreeMap::<K, u32>::new();
-        let stop_gap = Ord::max(stop_gap, 1);
-
-        for (keychain, spks) in keychain_spks {
-            let mut spks = spks.into_iter();
-            let mut last_index = Option::<u32>::None;
-            let mut last_active_index = Option::<u32>::None;
-
-            loop {
-                let handles = spks
-                    .by_ref()
-                    .take(parallel_requests)
-                    .map(|(spk_index, spk)| {
-                        let client = self.clone();
-                        async move {
-                            let mut last_seen = None;
-                            let mut spk_txs = Vec::new();
-                            loop {
-                                let txs = client.scripthash_txs(&spk, last_seen).await?;
-                                let tx_count = txs.len();
-                                last_seen = txs.last().map(|tx| tx.txid);
-                                spk_txs.extend(txs);
-                                if tx_count < 25 {
-                                    break Result::<_, Error>::Ok((spk_index, spk_txs));
-                                }
-                            }
-                        }
-                    })
-                    .collect::<FuturesOrdered<_>>();
-
-                if handles.is_empty() {
-                    break;
-                }
-
-                for (index, txs) in handles.try_collect::<Vec<TxsOfSpkIndex>>().await? {
-                    last_index = Some(index);
-                    if !txs.is_empty() {
-                        last_active_index = Some(index);
-                    }
-                    for tx in txs {
-                        let _ = graph.insert_tx(tx.to_tx());
-                        if let Some(anchor) = anchor_from_status(&tx.status) {
-                            let _ = graph.insert_anchor(tx.txid, anchor);
-                        }
-
-                        let previous_outputs = tx.vin.iter().filter_map(|vin| {
-                            let prevout = vin.prevout.as_ref()?;
-                            Some((
-                                OutPoint {
-                                    txid: vin.txid,
-                                    vout: vin.vout,
-                                },
-                                TxOut {
-                                    script_pubkey: prevout.scriptpubkey.clone(),
-                                    value: Amount::from_sat(prevout.value),
-                                },
-                            ))
-                        });
-
-                        for (outpoint, txout) in previous_outputs {
-                            let _ = graph.insert_txout(outpoint, txout);
-                        }
-                    }
-                }
-
-                let last_index = last_index.expect("Must be set since handles wasn't empty.");
-                let gap_limit_reached = if let Some(i) = last_active_index {
-                    last_index >= i.saturating_add(stop_gap as u32)
-                } else {
-                    last_index + 1 >= stop_gap as u32
-                };
-                if gap_limit_reached {
-                    break;
-                }
-            }
-
-            if let Some(last_active_index) = last_active_index {
-                last_active_indexes.insert(keychain, last_active_index);
-            }
-        }
-
-        Ok((graph, last_active_indexes))
-    }
-
-    async fn sync(
-        &self,
-        misc_spks: impl IntoIterator<IntoIter = impl Iterator<Item = ScriptBuf> + Send> + Send,
-        txids: impl IntoIterator<IntoIter = impl Iterator<Item = Txid> + Send> + Send,
-        outpoints: impl IntoIterator<IntoIter = impl Iterator<Item = OutPoint> + Send> + Send,
-        parallel_requests: usize,
-    ) -> Result<TxGraph<ConfirmationTimeHeightAnchor>, Error> {
-        let mut graph = self
-            .full_scan(
+    ) -> Result<ChainGraph<ConfirmationTime>, Error> {
+        let wallet_scan = self
+            .scan(
+                local_chain,
                [(
                    (),
                    misc_spks
@@ -275,60 +73,244 @@ impl EsploraAsyncExt for esplora_client::AsyncClient {
                        .map(|(i, spk)| (i as u32, spk)),
                )]
                .into(),
+                txids,
+                outpoints,
                usize::MAX,
                parallel_requests,
            )
-            .await
-            .map(|(g, _)| g)?;
+            .await?;

-        let mut txids = txids.into_iter();
-        loop {
-            let handles = txids
-                .by_ref()
-                .take(parallel_requests)
-                .filter(|&txid| graph.get_tx(txid).is_none())
-                .map(|txid| {
-                    let client = self.clone();
-                    async move { client.get_tx_status(&txid).await.map(|s| (txid, s)) }
-                })
-                .collect::<FuturesOrdered<_>>();
+        Ok(wallet_scan.update)
+    }
+}

-            if handles.is_empty() {
+#[cfg(feature = "async")]
+#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
+#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
+impl EsploraAsyncExt for esplora_client::AsyncClient {
+    #[allow(clippy::result_large_err)] // FIXME
+    async fn scan<K: Ord + Clone + Send>(
+        &self,
+        local_chain: &BTreeMap<u32, BlockHash>,
+        keychain_spks: BTreeMap<
+            K,
+            impl IntoIterator<IntoIter = impl Iterator<Item = (u32, Script)> + Send> + Send,
+        >,
+        txids: impl IntoIterator<IntoIter = impl Iterator<Item = Txid> + Send> + Send,
+        outpoints: impl IntoIterator<IntoIter = impl Iterator<Item = OutPoint> + Send> + Send,
+        stop_gap: usize,
+        parallel_requests: usize,
+    ) -> Result<KeychainScan<K, ConfirmationTime>, Error> {
+        let txids = txids.into_iter();
+        let outpoints = outpoints.into_iter();
+        let parallel_requests = parallel_requests.max(1);
+        let mut scan = KeychainScan::default();
+        let update = &mut scan.update;
+        let last_active_indices = &mut scan.last_active_indices;
+
+        for (&height, &original_hash) in local_chain.iter().rev() {
+            let update_block_id = BlockId {
+                height,
+                hash: self.get_block_hash(height).await?,
+            };
+            let _ = update
+                .insert_checkpoint(update_block_id)
+                .expect("cannot repeat height here");
+            if update_block_id.hash == original_hash {
                break;
            }
-
-            for (txid, status) in handles.try_collect::<Vec<(Txid, TxStatus)>>().await? {
-                if let Some(anchor) = anchor_from_status(&status) {
-                    let _ = graph.insert_anchor(txid, anchor);
+        }
+        let tip_at_start = BlockId {
+            height: self.get_height().await?,
+            hash: self.get_tip_hash().await?,
+        };
+        if let Err(failure) = update.insert_checkpoint(tip_at_start) {
+            match failure {
+                sparse_chain::InsertCheckpointError::HashNotMatching { .. } => {
+                    // there was a re-org before we started scanning. We haven't consumed any iterators, so calling this function recursively is safe.
+                    return EsploraAsyncExt::scan(
+                        self,
+                        local_chain,
+                        keychain_spks,
+                        txids,
+                        outpoints,
+                        stop_gap,
+                        parallel_requests,
+                    )
+                    .await;
                }
            }
        }

-        for op in outpoints.into_iter() {
-            if graph.get_tx(op.txid).is_none() {
-                if let Some(tx) = self.get_tx(&op.txid).await? {
-                    let _ = graph.insert_tx(tx);
+        for (keychain, spks) in keychain_spks {
+            let mut spks = spks.into_iter();
+            let mut last_active_index = None;
+            let mut empty_scripts = 0;
+            type IndexWithTxs = (u32, Vec<esplora_client::Tx>);
+
+            loop {
+                let futures: FuturesOrdered<_> = (0..parallel_requests)
+                    .filter_map(|_| {
+                        let (index, script) = spks.next()?;
+                        let client = self.clone();
+                        Some(async move {
+                            let mut related_txs = client.scripthash_txs(&script, None).await?;
+
+                            let n_confirmed =
+                                related_txs.iter().filter(|tx| tx.status.confirmed).count();
+                            // esplora pages on 25 confirmed transactions. If there are 25 or more we
+                            // keep requesting to see if there's more.
+                            if n_confirmed >= 25 {
+                                loop {
+                                    let new_related_txs = client
+                                        .scripthash_txs(
+                                            &script,
+                                            Some(related_txs.last().unwrap().txid),
+                                        )
+                                        .await?;
+                                    let n = new_related_txs.len();
+                                    related_txs.extend(new_related_txs);
+                                    // we've reached the end
+                                    if n < 25 {
+                                        break;
+                                    }
+                                }
+                            }
+
+                            Result::<_, esplora_client::Error>::Ok((index, related_txs))
+                        })
+                    })
+                    .collect();
+
+                let n_futures = futures.len();
+
+                let idx_with_tx: Vec<IndexWithTxs> = futures.try_collect().await?;
+
+                for (index, related_txs) in idx_with_tx {
+                    if related_txs.is_empty() {
+                        empty_scripts += 1;
+                    } else {
+                        last_active_index = Some(index);
+                        empty_scripts = 0;
+                    }
+                    for tx in related_txs {
+                        let confirmation_time =
+                            map_confirmation_time(&tx.status, tip_at_start.height);
+
+                        if let Err(failure) = update.insert_tx(tx.to_tx(), confirmation_time) {
+                            use bdk_chain::{
+                                chain_graph::InsertTxError, sparse_chain::InsertTxError::*,
+                            };
+                            match failure {
+                                InsertTxError::Chain(TxTooHigh { .. }) => {
+                                    unreachable!("chain position already checked earlier")
+                                }
+                                InsertTxError::Chain(TxMovedUnexpectedly { .. })
+                                | InsertTxError::UnresolvableConflict(_) => {
+                                    /* implies reorg during a scan. We deal with that below */
+                                }
+                            }
+                        }
+                    }
                }
-                let status = self.get_tx_status(&op.txid).await?;
-                if let Some(anchor) = anchor_from_status(&status) {
-                    let _ = graph.insert_anchor(op.txid, anchor);
+
+                if n_futures == 0 || empty_scripts >= stop_gap {
+                    break;
                }
            }

-            if let Some(op_status) = self.get_output_status(&op.txid, op.vout as _).await? {
-                if let Some(txid) = op_status.txid {
-                    if graph.get_tx(txid).is_none() {
-                        if let Some(tx) = self.get_tx(&txid).await? {
-                            let _ = graph.insert_tx(tx);
+            if let Some(last_active_index) = last_active_index {
+                last_active_indices.insert(keychain, last_active_index);
+            }
+        }
+
+        for txid in txids {
+            let (tx, tx_status) =
+                match (self.get_tx(&txid).await?, self.get_tx_status(&txid).await?) {
+                    (Some(tx), Some(tx_status)) => (tx, tx_status),
+                    _ => continue,
+                };
+
+            let confirmation_time = map_confirmation_time(&tx_status, tip_at_start.height);
+
+            if let Err(failure) = update.insert_tx(tx, confirmation_time) {
+                use bdk_chain::{chain_graph::InsertTxError, sparse_chain::InsertTxError::*};
+                match failure {
+                    InsertTxError::Chain(TxTooHigh { .. }) => {
+                        unreachable!("chain position already checked earlier")
+                    }
+                    InsertTxError::Chain(TxMovedUnexpectedly { .. })
+                    | InsertTxError::UnresolvableConflict(_) => {
+                        /* implies reorg during a scan. We deal with that below */
+                    }
+                }
+            }
+        }
+
+        for op in outpoints {
+            let mut op_txs = Vec::with_capacity(2);
+            if let (Some(tx), Some(tx_status)) = (
+                self.get_tx(&op.txid).await?,
+                self.get_tx_status(&op.txid).await?,
+            ) {
+                op_txs.push((tx, tx_status));
+                if let Some(OutputStatus {
+                    txid: Some(txid),
+                    status: Some(spend_status),
+                    ..
+                }) = self.get_output_status(&op.txid, op.vout as _).await?
+                {
+                    if let Some(spend_tx) = self.get_tx(&txid).await? {
+                        op_txs.push((spend_tx, spend_status));
+                    }
+                }
+            }
+
+            for (tx, status) in op_txs {
+                let confirmation_time = map_confirmation_time(&status, tip_at_start.height);
+
+                if let Err(failure) = update.insert_tx(tx, confirmation_time) {
+                    use bdk_chain::{chain_graph::InsertTxError, sparse_chain::InsertTxError::*};
+                    match failure {
+                        InsertTxError::Chain(TxTooHigh { .. }) => {
+                            unreachable!("chain position already checked earlier")
                        }
-                        let status = self.get_tx_status(&txid).await?;
-                        if let Some(anchor) = anchor_from_status(&status) {
-                            let _ = graph.insert_anchor(txid, anchor);
+                        InsertTxError::Chain(TxMovedUnexpectedly { .. })
+                        | InsertTxError::UnresolvableConflict(_) => {
+                            /* implies reorg during a scan. We deal with that below */
                        }
                    }
                }
            }
        }
-        Ok(graph)
+
+        let reorg_occurred = {
+            if let Some(checkpoint) = update.chain().latest_checkpoint() {
+                self.get_block_hash(checkpoint.height).await? != checkpoint.hash
+            } else {
+                false
+            }
+        };
+
+        if reorg_occurred {
+            // A reorg occurred, so let's find out where all the txids we found are in the chain now.
+            // XXX: collect required because of weird type naming issues
+            let txids_found = update
+                .chain()
+                .txids()
+                .map(|(_, txid)| *txid)
+                .collect::<Vec<_>>();
+            scan.update = EsploraAsyncExt::scan_without_keychain(
+                self,
+                local_chain,
+                [],
+                txids_found,
+                [],
+                parallel_requests,
+            )
+            .await?;
+        }
+
+        Ok(scan)
    }
 }
--- a/crates/esplora/src/blocking_ext.rs
+++ b/crates/esplora/src/blocking_ext.rs
@@ -1,331 +1,290 @@
-use std::thread::JoinHandle;
+use std::collections::BTreeMap;

-use bdk_chain::collections::btree_map;
-use bdk_chain::collections::BTreeMap;
 use bdk_chain::{
-    bitcoin::{Amount, BlockHash, OutPoint, ScriptBuf, TxOut, Txid},
-    local_chain::{self, CheckPoint},
-    BlockId, ConfirmationTimeHeightAnchor, TxGraph,
+    bitcoin::{BlockHash, OutPoint, Script, Txid},
+    chain_graph::ChainGraph,
+    keychain::KeychainScan,
+    sparse_chain, BlockId, ConfirmationTime,
 };
-use esplora_client::TxStatus;
+use esplora_client::{Error, OutputStatus};

-use crate::anchor_from_status;
+use crate::map_confirmation_time;

-/// [`esplora_client::Error`]
-type Error = Box<esplora_client::Error>;
-
-/// Trait to extend the functionality of [`esplora_client::BlockingClient`].
+/// Trait to extend [`esplora_client::BlockingClient`] functionality.
 ///
 /// Refer to [crate-level documentation] for more.
 ///
 /// [crate-level documentation]: crate
 pub trait EsploraExt {
-    /// Prepare a [`LocalChain`] update with blocks fetched from Esplora.
+    /// Scan the blockchain (via esplora) for the data specified and returns a [`KeychainScan`].
    ///
-    /// * `local_tip` is the previous tip of [`LocalChain::tip`].
-    /// * `request_heights` is the block heights that we are interested in fetching from Esplora.
+    /// - `local_chain`: the most recent block hashes present locally
+    /// - `keychain_spks`: keychains that we want to scan transactions for
+    /// - `txids`: transactions for which we want updated [`ChainPosition`]s
+    /// - `outpoints`: transactions associated with these outpoints (residing, spending) that we
+    ///     want to included in the update
    ///
-    /// The result of this method can be applied to [`LocalChain::apply_update`].
-    ///
-    /// ## Consistency
-    ///
-    /// The chain update returned is guaranteed to be consistent as long as there is not a *large* re-org
-    /// during the call. The size of re-org we can tollerate is server dependent but will be at
-    /// least 10.
-    ///
-    /// [`LocalChain`]: bdk_chain::local_chain::LocalChain
-    /// [`LocalChain::tip`]: bdk_chain::local_chain::LocalChain::tip
-    /// [`LocalChain::apply_update`]: bdk_chain::local_chain::LocalChain::apply_update
-    fn update_local_chain(
-        &self,
-        local_tip: CheckPoint,
-        request_heights: impl IntoIterator<Item = u32>,
-    ) -> Result<local_chain::Update, Error>;
-
-    /// Full scan the keychain scripts specified with the blockchain (via an Esplora client) and
-    /// returns a [`TxGraph`] and a map of last active indices.
-    ///
-    /// * `keychain_spks`: keychains that we want to scan transactions for
-    ///
-    /// The full scan for each keychain stops after a gap of `stop_gap` script pubkeys with no associated
+    /// The scan for each keychain stops after a gap of `stop_gap` script pubkeys with no associated
    /// transactions. `parallel_requests` specifies the max number of HTTP requests to make in
    /// parallel.
    ///
-    /// ## Note
-    ///
-    /// `stop_gap` is defined as "the maximum number of consecutive unused addresses".
-    /// For example, with a `stop_gap` of  3, `full_scan` will keep scanning
-    /// until it encounters 3 consecutive script pubkeys with no associated transactions.
-    ///
-    /// This follows the same approach as other Bitcoin-related software,
-    /// such as [Electrum](https://electrum.readthedocs.io/en/latest/faq.html#what-is-the-gap-limit),
-    /// [BTCPay Server](https://docs.btcpayserver.org/FAQ/Wallet/#the-gap-limit-problem),
-    /// and [Sparrow](https://www.sparrowwallet.com/docs/faq.html#ive-restored-my-wallet-but-some-of-my-funds-are-missing).
-    ///
-    /// A `stop_gap` of 0 will be treated as a `stop_gap` of 1.
-    fn full_scan<K: Ord + Clone>(
+    /// [`ChainPosition`]: bdk_chain::sparse_chain::ChainPosition
+    #[allow(clippy::result_large_err)] // FIXME
+    fn scan<K: Ord + Clone>(
        &self,
-        keychain_spks: BTreeMap<K, impl IntoIterator<Item = (u32, ScriptBuf)>>,
+        local_chain: &BTreeMap<u32, BlockHash>,
+        keychain_spks: BTreeMap<K, impl IntoIterator<Item = (u32, Script)>>,
+        txids: impl IntoIterator<Item = Txid>,
+        outpoints: impl IntoIterator<Item = OutPoint>,
        stop_gap: usize,
        parallel_requests: usize,
-    ) -> Result<(TxGraph<ConfirmationTimeHeightAnchor>, BTreeMap<K, u32>), Error>;
+    ) -> Result<KeychainScan<K, ConfirmationTime>, Error>;

-    /// Sync a set of scripts with the blockchain (via an Esplora client) for the data
-    /// specified and return a [`TxGraph`].
+    /// Convenience method to call [`scan`] without requiring a keychain.
    ///
-    /// * `misc_spks`: scripts that we want to sync transactions for
-    /// * `txids`: transactions for which we want updated [`ConfirmationTimeHeightAnchor`]s
-    /// * `outpoints`: transactions associated with these outpoints (residing, spending) that we
-    ///     want to include in the update
-    ///
-    /// If the scripts to sync are unknown, such as when restoring or importing a keychain that
-    /// may include scripts that have been used, use [`full_scan`] with the keychain.
-    ///
-    /// [`full_scan`]: EsploraExt::full_scan
-    fn sync(
+    /// [`scan`]: EsploraExt::scan
+    #[allow(clippy::result_large_err)] // FIXME
+    fn scan_without_keychain(
        &self,
-        misc_spks: impl IntoIterator<Item = ScriptBuf>,
+        local_chain: &BTreeMap<u32, BlockHash>,
+        misc_spks: impl IntoIterator<Item = Script>,
        txids: impl IntoIterator<Item = Txid>,
        outpoints: impl IntoIterator<Item = OutPoint>,
        parallel_requests: usize,
-    ) -> Result<TxGraph<ConfirmationTimeHeightAnchor>, Error>;
+    ) -> Result<ChainGraph<ConfirmationTime>, Error> {
+        let wallet_scan = self.scan(
+            local_chain,
+            [(
+                (),
+                misc_spks
+                    .into_iter()
+                    .enumerate()
+                    .map(|(i, spk)| (i as u32, spk)),
+            )]
+            .into(),
+            txids,
+            outpoints,
+            usize::MAX,
+            parallel_requests,
+        )?;
+
+        Ok(wallet_scan.update)
+    }
 }

 impl EsploraExt for esplora_client::BlockingClient {
-    fn update_local_chain(
+    fn scan<K: Ord + Clone>(
        &self,
-        local_tip: CheckPoint,
-        request_heights: impl IntoIterator<Item = u32>,
-    ) -> Result<local_chain::Update, Error> {
-        // Fetch latest N (server dependent) blocks from Esplora. The server guarantees these are
-        // consistent.
-        let mut fetched_blocks = self
-            .get_blocks(None)?
-            .into_iter()
-            .map(|b| (b.time.height, b.id))
-            .collect::<BTreeMap<u32, BlockHash>>();
-        let new_tip_height = fetched_blocks
-            .keys()
-            .last()
-            .copied()
-            .expect("must atleast have one block");
+        local_chain: &BTreeMap<u32, BlockHash>,
+        keychain_spks: BTreeMap<K, impl IntoIterator<Item = (u32, Script)>>,
+        txids: impl IntoIterator<Item = Txid>,
+        outpoints: impl IntoIterator<Item = OutPoint>,
+        stop_gap: usize,
+        parallel_requests: usize,
+    ) -> Result<KeychainScan<K, ConfirmationTime>, Error> {
+        let parallel_requests = parallel_requests.max(1);
+        let mut scan = KeychainScan::default();
+        let update = &mut scan.update;
+        let last_active_indices = &mut scan.last_active_indices;

-        // Fetch blocks of heights that the caller is interested in, skipping blocks that are
-        // already fetched when constructing `fetched_blocks`.
-        for height in request_heights {
-            // do not fetch blocks higher than remote tip
-            if height > new_tip_height {
-                continue;
-            }
-            // only fetch what is missing
-            if let btree_map::Entry::Vacant(entry) = fetched_blocks.entry(height) {
-                // ❗The return value of `get_block_hash` is not strictly guaranteed to be consistent
-                // with the chain at the time of `get_blocks` above (there could have been a deep
-                // re-org). Since `get_blocks` returns 10 (or so) blocks we are assuming that it's
-                // not possible to have a re-org deeper than that.
-                entry.insert(self.get_block_hash(height)?);
-            }
-        }
-
-        // Ensure `fetched_blocks` can create an update that connects with the original chain by
-        // finding a "Point of Agreement".
-        for (height, local_hash) in local_tip.iter().map(|cp| (cp.height(), cp.hash())) {
-            if height > new_tip_height {
-                continue;
-            }
-
-            let fetched_hash = match fetched_blocks.entry(height) {
-                btree_map::Entry::Occupied(entry) => *entry.get(),
-                btree_map::Entry::Vacant(entry) => *entry.insert(self.get_block_hash(height)?),
+        for (&height, &original_hash) in local_chain.iter().rev() {
+            let update_block_id = BlockId {
+                height,
+                hash: self.get_block_hash(height)?,
            };
-
-            // We have found point of agreement so the update will connect!
-            if fetched_hash == local_hash {
+            let _ = update
+                .insert_checkpoint(update_block_id)
+                .expect("cannot repeat height here");
+            if update_block_id.hash == original_hash {
                break;
            }
        }
-
-        Ok(local_chain::Update {
-            tip: CheckPoint::from_block_ids(fetched_blocks.into_iter().map(BlockId::from))
-                .expect("must be in height order"),
-            introduce_older_blocks: true,
-        })
-    }
-
-    fn full_scan<K: Ord + Clone>(
-        &self,
-        keychain_spks: BTreeMap<K, impl IntoIterator<Item = (u32, ScriptBuf)>>,
-        stop_gap: usize,
-        parallel_requests: usize,
-    ) -> Result<(TxGraph<ConfirmationTimeHeightAnchor>, BTreeMap<K, u32>), Error> {
-        type TxsOfSpkIndex = (u32, Vec<esplora_client::Tx>);
-        let parallel_requests = Ord::max(parallel_requests, 1);
-        let mut graph = TxGraph::<ConfirmationTimeHeightAnchor>::default();
-        let mut last_active_indexes = BTreeMap::<K, u32>::new();
-        let stop_gap = Ord::max(stop_gap, 1);
+        let tip_at_start = BlockId {
+            height: self.get_height()?,
+            hash: self.get_tip_hash()?,
+        };
+        if let Err(failure) = update.insert_checkpoint(tip_at_start) {
+            match failure {
+                sparse_chain::InsertCheckpointError::HashNotMatching { .. } => {
+                    // there was a re-org before we started scanning. We haven't consumed any iterators, so calling this function recursively is safe.
+                    return EsploraExt::scan(
+                        self,
+                        local_chain,
+                        keychain_spks,
+                        txids,
+                        outpoints,
+                        stop_gap,
+                        parallel_requests,
+                    );
+                }
+            }
+        }

        for (keychain, spks) in keychain_spks {
            let mut spks = spks.into_iter();
-            let mut last_index = Option::<u32>::None;
-            let mut last_active_index = Option::<u32>::None;
+            let mut last_active_index = None;
+            let mut empty_scripts = 0;
+            type IndexWithTxs = (u32, Vec<esplora_client::Tx>);

            loop {
-                let handles = spks
-                    .by_ref()
-                    .take(parallel_requests)
-                    .map(|(spk_index, spk)| {
-                        std::thread::spawn({
+                let handles = (0..parallel_requests)
+                    .filter_map(
+                        |_| -> Option<std::thread::JoinHandle<Result<IndexWithTxs, _>>> {
+                            let (index, script) = spks.next()?;
                            let client = self.clone();
-                            move || -> Result<TxsOfSpkIndex, Error> {
-                                let mut last_seen = None;
-                                let mut spk_txs = Vec::new();
-                                loop {
-                                    let txs = client.scripthash_txs(&spk, last_seen)?;
-                                    let tx_count = txs.len();
-                                    last_seen = txs.last().map(|tx| tx.txid);
-                                    spk_txs.extend(txs);
-                                    if tx_count < 25 {
-                                        break Ok((spk_index, spk_txs));
+                            Some(std::thread::spawn(move || {
+                                let mut related_txs = client.scripthash_txs(&script, None)?;
+
+                                let n_confirmed =
+                                    related_txs.iter().filter(|tx| tx.status.confirmed).count();
+                                // esplora pages on 25 confirmed transactions. If there are 25 or more we
+                                // keep requesting to see if there's more.
+                                if n_confirmed >= 25 {
+                                    loop {
+                                        let new_related_txs = client.scripthash_txs(
+                                            &script,
+                                            Some(related_txs.last().unwrap().txid),
+                                        )?;
+                                        let n = new_related_txs.len();
+                                        related_txs.extend(new_related_txs);
+                                        // we've reached the end
+                                        if n < 25 {
+                                            break;
+                                        }
                                    }
                                }
-                            }
-                        })
-                    })
-                    .collect::<Vec<JoinHandle<Result<TxsOfSpkIndex, Error>>>>();

-                if handles.is_empty() {
-                    break;
-                }
+                                Result::<_, esplora_client::Error>::Ok((index, related_txs))
+                            }))
+                        },
+                    )
+                    .collect::<Vec<_>>();
+
+                let n_handles = handles.len();

                for handle in handles {
-                    let (index, txs) = handle.join().expect("thread must not panic")?;
-                    last_index = Some(index);
-                    if !txs.is_empty() {
+                    let (index, related_txs) = handle.join().unwrap()?; // TODO: don't unwrap
+                    if related_txs.is_empty() {
+                        empty_scripts += 1;
+                    } else {
                        last_active_index = Some(index);
+                        empty_scripts = 0;
                    }
-                    for tx in txs {
-                        let _ = graph.insert_tx(tx.to_tx());
-                        if let Some(anchor) = anchor_from_status(&tx.status) {
-                            let _ = graph.insert_anchor(tx.txid, anchor);
-                        }
+                    for tx in related_txs {
+                        let confirmation_time =
+                            map_confirmation_time(&tx.status, tip_at_start.height);

-                        let previous_outputs = tx.vin.iter().filter_map(|vin| {
-                            let prevout = vin.prevout.as_ref()?;
-                            Some((
-                                OutPoint {
-                                    txid: vin.txid,
-                                    vout: vin.vout,
-                                },
-                                TxOut {
-                                    script_pubkey: prevout.scriptpubkey.clone(),
-                                    value: Amount::from_sat(prevout.value),
-                                },
-                            ))
-                        });
-
-                        for (outpoint, txout) in previous_outputs {
-                            let _ = graph.insert_txout(outpoint, txout);
+                        if let Err(failure) = update.insert_tx(tx.to_tx(), confirmation_time) {
+                            use bdk_chain::{
+                                chain_graph::InsertTxError, sparse_chain::InsertTxError::*,
+                            };
+                            match failure {
+                                InsertTxError::Chain(TxTooHigh { .. }) => {
+                                    unreachable!("chain position already checked earlier")
+                                }
+                                InsertTxError::Chain(TxMovedUnexpectedly { .. })
+                                | InsertTxError::UnresolvableConflict(_) => {
+                                    /* implies reorg during a scan. We deal with that below */
+                                }
+                            }
                        }
                    }
                }

-                let last_index = last_index.expect("Must be set since handles wasn't empty.");
-                let gap_limit_reached = if let Some(i) = last_active_index {
-                    last_index >= i.saturating_add(stop_gap as u32)
-                } else {
-                    last_index + 1 >= stop_gap as u32
-                };
-                if gap_limit_reached {
+                if n_handles == 0 || empty_scripts >= stop_gap {
                    break;
                }
            }

            if let Some(last_active_index) = last_active_index {
-                last_active_indexes.insert(keychain, last_active_index);
+                last_active_indices.insert(keychain, last_active_index);
            }
        }

-        Ok((graph, last_active_indexes))
-    }
+        for txid in txids.into_iter() {
+            let (tx, tx_status) = match (self.get_tx(&txid)?, self.get_tx_status(&txid)?) {
+                (Some(tx), Some(tx_status)) => (tx, tx_status),
+                _ => continue,
+            };

-    fn sync(
-        &self,
-        misc_spks: impl IntoIterator<Item = ScriptBuf>,
-        txids: impl IntoIterator<Item = Txid>,
-        outpoints: impl IntoIterator<Item = OutPoint>,
-        parallel_requests: usize,
-    ) -> Result<TxGraph<ConfirmationTimeHeightAnchor>, Error> {
-        let mut graph = self
-            .full_scan(
-                [(
-                    (),
-                    misc_spks
-                        .into_iter()
-                        .enumerate()
-                        .map(|(i, spk)| (i as u32, spk)),
-                )]
-                .into(),
-                usize::MAX,
-                parallel_requests,
-            )
-            .map(|(g, _)| g)?;
+            let confirmation_time = map_confirmation_time(&tx_status, tip_at_start.height);

-        let mut txids = txids.into_iter();
-        loop {
-            let handles = txids
-                .by_ref()
-                .take(parallel_requests)
-                .filter(|&txid| graph.get_tx(txid).is_none())
-                .map(|txid| {
-                    std::thread::spawn({
-                        let client = self.clone();
-                        move || {
-                            client
-                                .get_tx_status(&txid)
-                                .map_err(Box::new)
-                                .map(|s| (txid, s))
-                        }
-                    })
-                })
-                .collect::<Vec<JoinHandle<Result<(Txid, TxStatus), Error>>>>();
-
-            if handles.is_empty() {
-                break;
-            }
-
-            for handle in handles {
-                let (txid, status) = handle.join().expect("thread must not panic")?;
-                if let Some(anchor) = anchor_from_status(&status) {
-                    let _ = graph.insert_anchor(txid, anchor);
+            if let Err(failure) = update.insert_tx(tx, confirmation_time) {
+                use bdk_chain::{chain_graph::InsertTxError, sparse_chain::InsertTxError::*};
+                match failure {
+                    InsertTxError::Chain(TxTooHigh { .. }) => {
+                        unreachable!("chain position already checked earlier")
+                    }
+                    InsertTxError::Chain(TxMovedUnexpectedly { .. })
+                    | InsertTxError::UnresolvableConflict(_) => {
+                        /* implies reorg during a scan. We deal with that below */
+                    }
                }
            }
        }

-        for op in outpoints {
-            if graph.get_tx(op.txid).is_none() {
-                if let Some(tx) = self.get_tx(&op.txid)? {
-                    let _ = graph.insert_tx(tx);
-                }
-                let status = self.get_tx_status(&op.txid)?;
-                if let Some(anchor) = anchor_from_status(&status) {
-                    let _ = graph.insert_anchor(op.txid, anchor);
+        for op in outpoints.into_iter() {
+            let mut op_txs = Vec::with_capacity(2);
+            if let (Some(tx), Some(tx_status)) =
+                (self.get_tx(&op.txid)?, self.get_tx_status(&op.txid)?)
+            {
+                op_txs.push((tx, tx_status));
+                if let Some(OutputStatus {
+                    txid: Some(txid),
+                    status: Some(spend_status),
+                    ..
+                }) = self.get_output_status(&op.txid, op.vout as _)?
+                {
+                    if let Some(spend_tx) = self.get_tx(&txid)? {
+                        op_txs.push((spend_tx, spend_status));
+                    }
                }
            }

-            if let Some(op_status) = self.get_output_status(&op.txid, op.vout as _)? {
-                if let Some(txid) = op_status.txid {
-                    if graph.get_tx(txid).is_none() {
-                        if let Some(tx) = self.get_tx(&txid)? {
-                            let _ = graph.insert_tx(tx);
+            for (tx, status) in op_txs {
+                let confirmation_time = map_confirmation_time(&status, tip_at_start.height);
+
+                if let Err(failure) = update.insert_tx(tx, confirmation_time) {
+                    use bdk_chain::{chain_graph::InsertTxError, sparse_chain::InsertTxError::*};
+                    match failure {
+                        InsertTxError::Chain(TxTooHigh { .. }) => {
+                            unreachable!("chain position already checked earlier")
                        }
-                        let status = self.get_tx_status(&txid)?;
-                        if let Some(anchor) = anchor_from_status(&status) {
-                            let _ = graph.insert_anchor(txid, anchor);
+                        InsertTxError::Chain(TxMovedUnexpectedly { .. })
+                        | InsertTxError::UnresolvableConflict(_) => {
+                            /* implies reorg during a scan. We deal with that below */
                        }
                    }
                }
            }
        }
-        Ok(graph)
+
+        let reorg_occurred = {
+            if let Some(checkpoint) = update.chain().latest_checkpoint() {
+                self.get_block_hash(checkpoint.height)? != checkpoint.hash
+            } else {
+                false
+            }
+        };
+
+        if reorg_occurred {
+            // A reorg occurred, so let's find out where all the txids we found are now in the chain.
+            // XXX: collect required because of weird type naming issues
+            let txids_found = update
+                .chain()
+                .txids()
+                .map(|(_, txid)| *txid)
+                .collect::<Vec<_>>();
+            scan.update = EsploraExt::scan_without_keychain(
+                self,
+                local_chain,
+                [],
+                txids_found,
+                [],
+                parallel_requests,
+            )?;
+        }
+
+        Ok(scan)
    }
 }
--- a/crates/esplora/src/lib.rs
+++ b/crates/esplora/src/lib.rs
@@ -1,22 +1,5 @@
 #![doc = include_str!("../README.md")]
-
-//! This crate is used for updating structures of [`bdk_chain`] with data from an Esplora server.
-//!
-//! The two primary methods are [`EsploraExt::sync`] and [`EsploraExt::full_scan`]. In most cases
-//! [`EsploraExt::sync`] is used to sync the transaction histories of scripts that the application
-//! cares about, for example the scripts for all the receive addresses of a Wallet's keychain that it
-//! has shown a user. [`EsploraExt::full_scan`] is meant to be used when importing or restoring a
-//! keychain where the range of possibly used scripts is not known. In this case it is necessary to
-//! scan all keychain scripts until a number (the "stop gap") of unused scripts is discovered. For a
-//! sync or full scan the user receives relevant blockchain data and output updates for [`bdk_chain`]
-//! via a new [`TxGraph`] to be appended to any existing [`TxGraph`] data.
-//!
-//! Refer to [`example_esplora`] for a complete example.
-//!
-//! [`TxGraph`]: bdk_chain::tx_graph::TxGraph
-//! [`example_esplora`]: https://github.com/bitcoindevkit/bdk/tree/master/example-crates/example_esplora
-
-use bdk_chain::{BlockId, ConfirmationTimeHeightAnchor};
+use bdk_chain::ConfirmationTime;
 use esplora_client::TxStatus;

 pub use esplora_client;
@@ -31,20 +14,14 @@ mod async_ext;
 #[cfg(feature = "async")]
 pub use async_ext::*;

-fn anchor_from_status(status: &TxStatus) -> Option<ConfirmationTimeHeightAnchor> {
-    if let TxStatus {
-        block_height: Some(height),
-        block_hash: Some(hash),
-        block_time: Some(time),
-        ..
-    } = status.clone()
-    {
-        Some(ConfirmationTimeHeightAnchor {
-            anchor_block: BlockId { height, hash },
-            confirmation_height: height,
-            confirmation_time: time,
-        })
-    } else {
-        None
+pub(crate) fn map_confirmation_time(
+    tx_status: &TxStatus,
+    height_at_start: u32,
+) -> ConfirmationTime {
+    match (tx_status.block_time, tx_status.block_height) {
+        (Some(time), Some(height)) if height <= height_at_start => {
+            ConfirmationTime::Confirmed { height, time }
+        }
+        _ => ConfirmationTime::Unconfirmed,
    }
 }
--- a/crates/esplora/tests/async_ext.rs
+++ b/crates/esplora/tests/async_ext.rs
@@ -1,182 +0,0 @@
-use bdk_esplora::EsploraAsyncExt;
-use electrsd::bitcoind::anyhow;
-use electrsd::bitcoind::bitcoincore_rpc::RpcApi;
-use esplora_client::{self, Builder};
-use std::collections::{BTreeMap, HashSet};
-use std::str::FromStr;
-use std::thread::sleep;
-use std::time::Duration;
-
-use bdk_chain::bitcoin::{Address, Amount, Txid};
-use bdk_testenv::TestEnv;
-
-#[tokio::test]
-pub async fn test_update_tx_graph_without_keychain() -> anyhow::Result<()> {
-    let env = TestEnv::new()?;
-    let base_url = format!("http://{}", &env.electrsd.esplora_url.clone().unwrap());
-    let client = Builder::new(base_url.as_str()).build_async()?;
-
-    let receive_address0 =
-        Address::from_str("bcrt1qc6fweuf4xjvz4x3gx3t9e0fh4hvqyu2qw4wvxm")?.assume_checked();
-    let receive_address1 =
-        Address::from_str("bcrt1qfjg5lv3dvc9az8patec8fjddrs4aqtauadnagr")?.assume_checked();
-
-    let misc_spks = [
-        receive_address0.script_pubkey(),
-        receive_address1.script_pubkey(),
-    ];
-
-    let _block_hashes = env.mine_blocks(101, None)?;
-    let txid1 = env.bitcoind.client.send_to_address(
-        &receive_address1,
-        Amount::from_sat(10000),
-        None,
-        None,
-        None,
-        None,
-        Some(1),
-        None,
-    )?;
-    let txid2 = env.bitcoind.client.send_to_address(
-        &receive_address0,
-        Amount::from_sat(20000),
-        None,
-        None,
-        None,
-        None,
-        Some(1),
-        None,
-    )?;
-    let _block_hashes = env.mine_blocks(1, None)?;
-    while client.get_height().await.unwrap() < 102 {
-        sleep(Duration::from_millis(10))
-    }
-
-    let graph_update = client
-        .sync(
-            misc_spks.into_iter(),
-            vec![].into_iter(),
-            vec![].into_iter(),
-            1,
-        )
-        .await?;
-
-    // Check to see if we have the floating txouts available from our two created transactions'
-    // previous outputs in order to calculate transaction fees.
-    for tx in graph_update.full_txs() {
-        // Retrieve the calculated fee from `TxGraph`, which will panic if we do not have the
-        // floating txouts available from the transactions' previous outputs.
-        let fee = graph_update.calculate_fee(&tx.tx).expect("Fee must exist");
-
-        // Retrieve the fee in the transaction data from `bitcoind`.
-        let tx_fee = env
-            .bitcoind
-            .client
-            .get_transaction(&tx.txid, None)
-            .expect("Tx must exist")
-            .fee
-            .expect("Fee must exist")
-            .abs()
-            .to_sat() as u64;
-
-        // Check that the calculated fee matches the fee from the transaction data.
-        assert_eq!(fee, tx_fee);
-    }
-
-    let mut graph_update_txids: Vec<Txid> = graph_update.full_txs().map(|tx| tx.txid).collect();
-    graph_update_txids.sort();
-    let mut expected_txids = vec![txid1, txid2];
-    expected_txids.sort();
-    assert_eq!(graph_update_txids, expected_txids);
-    Ok(())
-}
-
-/// Test the bounds of the address scan depending on the `stop_gap`.
-#[tokio::test]
-pub async fn test_async_update_tx_graph_stop_gap() -> anyhow::Result<()> {
-    let env = TestEnv::new()?;
-    let base_url = format!("http://{}", &env.electrsd.esplora_url.clone().unwrap());
-    let client = Builder::new(base_url.as_str()).build_async()?;
-    let _block_hashes = env.mine_blocks(101, None)?;
-
-    // Now let's test the gap limit. First of all get a chain of 10 addresses.
-    let addresses = [
-        "bcrt1qj9f7r8r3p2y0sqf4r3r62qysmkuh0fzep473d2ar7rcz64wqvhssjgf0z4",
-        "bcrt1qmm5t0ch7vh2hryx9ctq3mswexcugqe4atkpkl2tetm8merqkthas3w7q30",
-        "bcrt1qut9p7ej7l7lhyvekj28xknn8gnugtym4d5qvnp5shrsr4nksmfqsmyn87g",
-        "bcrt1qqz0xtn3m235p2k96f5wa2dqukg6shxn9n3txe8arlrhjh5p744hsd957ww",
-        "bcrt1q9c0t62a8l6wfytmf2t9lfj35avadk3mm8g4p3l84tp6rl66m48sqrme7wu",
-        "bcrt1qkmh8yrk2v47cklt8dytk8f3ammcwa4q7dzattedzfhqzvfwwgyzsg59zrh",
-        "bcrt1qvgrsrzy07gjkkfr5luplt0azxtfwmwq5t62gum5jr7zwcvep2acs8hhnp2",
-        "bcrt1qw57edarcg50ansq8mk3guyrk78rk0fwvrds5xvqeupteu848zayq549av8",
-        "bcrt1qvtve5ekf6e5kzs68knvnt2phfw6a0yjqrlgat392m6zt9jsvyxhqfx67ef",
-        "bcrt1qw03ddumfs9z0kcu76ln7jrjfdwam20qtffmkcral3qtza90sp9kqm787uk",
-    ];
-    let addresses: Vec<_> = addresses
-        .into_iter()
-        .map(|s| Address::from_str(s).unwrap().assume_checked())
-        .collect();
-    let spks: Vec<_> = addresses
-        .iter()
-        .enumerate()
-        .map(|(i, addr)| (i as u32, addr.script_pubkey()))
-        .collect();
-    let mut keychains = BTreeMap::new();
-    keychains.insert(0, spks);
-
-    // Then receive coins on the 4th address.
-    let txid_4th_addr = env.bitcoind.client.send_to_address(
-        &addresses[3],
-        Amount::from_sat(10000),
-        None,
-        None,
-        None,
-        None,
-        Some(1),
-        None,
-    )?;
-    let _block_hashes = env.mine_blocks(1, None)?;
-    while client.get_height().await.unwrap() < 103 {
-        sleep(Duration::from_millis(10))
-    }
-
-    // A scan with a gap limit of 3 won't find the transaction, but a scan with a gap limit of 4
-    // will.
-    let (graph_update, active_indices) = client.full_scan(keychains.clone(), 3, 1).await?;
-    assert!(graph_update.full_txs().next().is_none());
-    assert!(active_indices.is_empty());
-    let (graph_update, active_indices) = client.full_scan(keychains.clone(), 4, 1).await?;
-    assert_eq!(graph_update.full_txs().next().unwrap().txid, txid_4th_addr);
-    assert_eq!(active_indices[&0], 3);
-
-    // Now receive a coin on the last address.
-    let txid_last_addr = env.bitcoind.client.send_to_address(
-        &addresses[addresses.len() - 1],
-        Amount::from_sat(10000),
-        None,
-        None,
-        None,
-        None,
-        Some(1),
-        None,
-    )?;
-    let _block_hashes = env.mine_blocks(1, None)?;
-    while client.get_height().await.unwrap() < 104 {
-        sleep(Duration::from_millis(10))
-    }
-
-    // A scan with gap limit 5 won't find the second transaction, but a scan with gap limit 6 will.
-    // The last active indice won't be updated in the first case but will in the second one.
-    let (graph_update, active_indices) = client.full_scan(keychains.clone(), 5, 1).await?;
-    let txs: HashSet<_> = graph_update.full_txs().map(|tx| tx.txid).collect();
-    assert_eq!(txs.len(), 1);
-    assert!(txs.contains(&txid_4th_addr));
-    assert_eq!(active_indices[&0], 3);
-    let (graph_update, active_indices) = client.full_scan(keychains, 6, 1).await?;
-    let txs: HashSet<_> = graph_update.full_txs().map(|tx| tx.txid).collect();
-    assert_eq!(txs.len(), 2);
-    assert!(txs.contains(&txid_4th_addr) && txs.contains(&txid_last_addr));
-    assert_eq!(active_indices[&0], 9);
-
-    Ok(())
-}
--- a/crates/esplora/tests/blocking_ext.rs
+++ b/crates/esplora/tests/blocking_ext.rs
@@ -1,375 +0,0 @@
-use bdk_chain::local_chain::LocalChain;
-use bdk_chain::BlockId;
-use bdk_esplora::EsploraExt;
-use electrsd::bitcoind::anyhow;
-use electrsd::bitcoind::bitcoincore_rpc::RpcApi;
-use esplora_client::{self, Builder};
-use std::collections::{BTreeMap, BTreeSet, HashSet};
-use std::str::FromStr;
-use std::thread::sleep;
-use std::time::Duration;
-
-use bdk_chain::bitcoin::{Address, Amount, Txid};
-use bdk_testenv::TestEnv;
-
-macro_rules! h {
-    ($index:literal) => {{
-        bdk_chain::bitcoin::hashes::Hash::hash($index.as_bytes())
-    }};
-}
-
-macro_rules! local_chain {
-    [ $(($height:expr, $block_hash:expr)), * ] => {{
-        #[allow(unused_mut)]
-        bdk_chain::local_chain::LocalChain::from_blocks([$(($height, $block_hash).into()),*].into_iter().collect())
-            .expect("chain must have genesis block")
-    }};
-}
-
-#[test]
-pub fn test_update_tx_graph_without_keychain() -> anyhow::Result<()> {
-    let env = TestEnv::new()?;
-    let base_url = format!("http://{}", &env.electrsd.esplora_url.clone().unwrap());
-    let client = Builder::new(base_url.as_str()).build_blocking();
-
-    let receive_address0 =
-        Address::from_str("bcrt1qc6fweuf4xjvz4x3gx3t9e0fh4hvqyu2qw4wvxm")?.assume_checked();
-    let receive_address1 =
-        Address::from_str("bcrt1qfjg5lv3dvc9az8patec8fjddrs4aqtauadnagr")?.assume_checked();
-
-    let misc_spks = [
-        receive_address0.script_pubkey(),
-        receive_address1.script_pubkey(),
-    ];
-
-    let _block_hashes = env.mine_blocks(101, None)?;
-    let txid1 = env.bitcoind.client.send_to_address(
-        &receive_address1,
-        Amount::from_sat(10000),
-        None,
-        None,
-        None,
-        None,
-        Some(1),
-        None,
-    )?;
-    let txid2 = env.bitcoind.client.send_to_address(
-        &receive_address0,
-        Amount::from_sat(20000),
-        None,
-        None,
-        None,
-        None,
-        Some(1),
-        None,
-    )?;
-    let _block_hashes = env.mine_blocks(1, None)?;
-    while client.get_height().unwrap() < 102 {
-        sleep(Duration::from_millis(10))
-    }
-
-    let graph_update = client.sync(
-        misc_spks.into_iter(),
-        vec![].into_iter(),
-        vec![].into_iter(),
-        1,
-    )?;
-
-    // Check to see if we have the floating txouts available from our two created transactions'
-    // previous outputs in order to calculate transaction fees.
-    for tx in graph_update.full_txs() {
-        // Retrieve the calculated fee from `TxGraph`, which will panic if we do not have the
-        // floating txouts available from the transactions' previous outputs.
-        let fee = graph_update.calculate_fee(&tx.tx).expect("Fee must exist");
-
-        // Retrieve the fee in the transaction data from `bitcoind`.
-        let tx_fee = env
-            .bitcoind
-            .client
-            .get_transaction(&tx.txid, None)
-            .expect("Tx must exist")
-            .fee
-            .expect("Fee must exist")
-            .abs()
-            .to_sat() as u64;
-
-        // Check that the calculated fee matches the fee from the transaction data.
-        assert_eq!(fee, tx_fee);
-    }
-
-    let mut graph_update_txids: Vec<Txid> = graph_update.full_txs().map(|tx| tx.txid).collect();
-    graph_update_txids.sort();
-    let mut expected_txids = vec![txid1, txid2];
-    expected_txids.sort();
-    assert_eq!(graph_update_txids, expected_txids);
-
-    Ok(())
-}
-
-/// Test the bounds of the address scan depending on the `stop_gap`.
-#[test]
-pub fn test_update_tx_graph_stop_gap() -> anyhow::Result<()> {
-    let env = TestEnv::new()?;
-    let base_url = format!("http://{}", &env.electrsd.esplora_url.clone().unwrap());
-    let client = Builder::new(base_url.as_str()).build_blocking();
-    let _block_hashes = env.mine_blocks(101, None)?;
-
-    // Now let's test the gap limit. First of all get a chain of 10 addresses.
-    let addresses = [
-        "bcrt1qj9f7r8r3p2y0sqf4r3r62qysmkuh0fzep473d2ar7rcz64wqvhssjgf0z4",
-        "bcrt1qmm5t0ch7vh2hryx9ctq3mswexcugqe4atkpkl2tetm8merqkthas3w7q30",
-        "bcrt1qut9p7ej7l7lhyvekj28xknn8gnugtym4d5qvnp5shrsr4nksmfqsmyn87g",
-        "bcrt1qqz0xtn3m235p2k96f5wa2dqukg6shxn9n3txe8arlrhjh5p744hsd957ww",
-        "bcrt1q9c0t62a8l6wfytmf2t9lfj35avadk3mm8g4p3l84tp6rl66m48sqrme7wu",
-        "bcrt1qkmh8yrk2v47cklt8dytk8f3ammcwa4q7dzattedzfhqzvfwwgyzsg59zrh",
-        "bcrt1qvgrsrzy07gjkkfr5luplt0azxtfwmwq5t62gum5jr7zwcvep2acs8hhnp2",
-        "bcrt1qw57edarcg50ansq8mk3guyrk78rk0fwvrds5xvqeupteu848zayq549av8",
-        "bcrt1qvtve5ekf6e5kzs68knvnt2phfw6a0yjqrlgat392m6zt9jsvyxhqfx67ef",
-        "bcrt1qw03ddumfs9z0kcu76ln7jrjfdwam20qtffmkcral3qtza90sp9kqm787uk",
-    ];
-    let addresses: Vec<_> = addresses
-        .into_iter()
-        .map(|s| Address::from_str(s).unwrap().assume_checked())
-        .collect();
-    let spks: Vec<_> = addresses
-        .iter()
-        .enumerate()
-        .map(|(i, addr)| (i as u32, addr.script_pubkey()))
-        .collect();
-    let mut keychains = BTreeMap::new();
-    keychains.insert(0, spks);
-
-    // Then receive coins on the 4th address.
-    let txid_4th_addr = env.bitcoind.client.send_to_address(
-        &addresses[3],
-        Amount::from_sat(10000),
-        None,
-        None,
-        None,
-        None,
-        Some(1),
-        None,
-    )?;
-    let _block_hashes = env.mine_blocks(1, None)?;
-    while client.get_height().unwrap() < 103 {
-        sleep(Duration::from_millis(10))
-    }
-
-    // A scan with a stop_gap of 3 won't find the transaction, but a scan with a gap limit of 4
-    // will.
-    let (graph_update, active_indices) = client.full_scan(keychains.clone(), 3, 1)?;
-    assert!(graph_update.full_txs().next().is_none());
-    assert!(active_indices.is_empty());
-    let (graph_update, active_indices) = client.full_scan(keychains.clone(), 4, 1)?;
-    assert_eq!(graph_update.full_txs().next().unwrap().txid, txid_4th_addr);
-    assert_eq!(active_indices[&0], 3);
-
-    // Now receive a coin on the last address.
-    let txid_last_addr = env.bitcoind.client.send_to_address(
-        &addresses[addresses.len() - 1],
-        Amount::from_sat(10000),
-        None,
-        None,
-        None,
-        None,
-        Some(1),
-        None,
-    )?;
-    let _block_hashes = env.mine_blocks(1, None)?;
-    while client.get_height().unwrap() < 104 {
-        sleep(Duration::from_millis(10))
-    }
-
-    // A scan with gap limit 5 won't find the second transaction, but a scan with gap limit 6 will.
-    // The last active indice won't be updated in the first case but will in the second one.
-    let (graph_update, active_indices) = client.full_scan(keychains.clone(), 5, 1)?;
-    let txs: HashSet<_> = graph_update.full_txs().map(|tx| tx.txid).collect();
-    assert_eq!(txs.len(), 1);
-    assert!(txs.contains(&txid_4th_addr));
-    assert_eq!(active_indices[&0], 3);
-    let (graph_update, active_indices) = client.full_scan(keychains, 6, 1)?;
-    let txs: HashSet<_> = graph_update.full_txs().map(|tx| tx.txid).collect();
-    assert_eq!(txs.len(), 2);
-    assert!(txs.contains(&txid_4th_addr) && txs.contains(&txid_last_addr));
-    assert_eq!(active_indices[&0], 9);
-
-    Ok(())
-}
-
-#[test]
-fn update_local_chain() -> anyhow::Result<()> {
-    const TIP_HEIGHT: u32 = 50;
-
-    let env = TestEnv::new()?;
-    let blocks = {
-        let bitcoind_client = &env.bitcoind.client;
-        assert_eq!(bitcoind_client.get_block_count()?, 1);
-        [
-            (0, bitcoind_client.get_block_hash(0)?),
-            (1, bitcoind_client.get_block_hash(1)?),
-        ]
-        .into_iter()
-        .chain((2..).zip(env.mine_blocks((TIP_HEIGHT - 1) as usize, None)?))
-        .collect::<BTreeMap<_, _>>()
-    };
-    // so new blocks can be seen by Electrs
-    let env = env.reset_electrsd()?;
-    let base_url = format!("http://{}", &env.electrsd.esplora_url.clone().unwrap());
-    let client = Builder::new(base_url.as_str()).build_blocking();
-
-    struct TestCase {
-        name: &'static str,
-        chain: LocalChain,
-        request_heights: &'static [u32],
-        exp_update_heights: &'static [u32],
-    }
-
-    let test_cases = [
-        TestCase {
-            name: "request_later_blocks",
-            chain: local_chain![(0, blocks[&0]), (21, blocks[&21])],
-            request_heights: &[22, 25, 28],
-            exp_update_heights: &[21, 22, 25, 28],
-        },
-        TestCase {
-            name: "request_prev_blocks",
-            chain: local_chain![(0, blocks[&0]), (1, blocks[&1]), (5, blocks[&5])],
-            request_heights: &[4],
-            exp_update_heights: &[4, 5],
-        },
-        TestCase {
-            name: "request_prev_blocks_2",
-            chain: local_chain![(0, blocks[&0]), (1, blocks[&1]), (10, blocks[&10])],
-            request_heights: &[4, 6],
-            exp_update_heights: &[4, 6, 10],
-        },
-        TestCase {
-            name: "request_later_and_prev_blocks",
-            chain: local_chain![(0, blocks[&0]), (7, blocks[&7]), (11, blocks[&11])],
-            request_heights: &[8, 9, 15],
-            exp_update_heights: &[8, 9, 11, 15],
-        },
-        TestCase {
-            name: "request_tip_only",
-            chain: local_chain![(0, blocks[&0]), (5, blocks[&5]), (49, blocks[&49])],
-            request_heights: &[TIP_HEIGHT],
-            exp_update_heights: &[49],
-        },
-        TestCase {
-            name: "request_nothing",
-            chain: local_chain![(0, blocks[&0]), (13, blocks[&13]), (23, blocks[&23])],
-            request_heights: &[],
-            exp_update_heights: &[23],
-        },
-        TestCase {
-            name: "request_nothing_during_reorg",
-            chain: local_chain![(0, blocks[&0]), (13, blocks[&13]), (23, h!("23"))],
-            request_heights: &[],
-            exp_update_heights: &[13, 23],
-        },
-        TestCase {
-            name: "request_nothing_during_reorg_2",
-            chain: local_chain![
-                (0, blocks[&0]),
-                (21, blocks[&21]),
-                (22, h!("22")),
-                (23, h!("23"))
-            ],
-            request_heights: &[],
-            exp_update_heights: &[21, 22, 23],
-        },
-        TestCase {
-            name: "request_prev_blocks_during_reorg",
-            chain: local_chain![
-                (0, blocks[&0]),
-                (21, blocks[&21]),
-                (22, h!("22")),
-                (23, h!("23"))
-            ],
-            request_heights: &[17, 20],
-            exp_update_heights: &[17, 20, 21, 22, 23],
-        },
-        TestCase {
-            name: "request_later_blocks_during_reorg",
-            chain: local_chain![
-                (0, blocks[&0]),
-                (9, blocks[&9]),
-                (22, h!("22")),
-                (23, h!("23"))
-            ],
-            request_heights: &[25, 27],
-            exp_update_heights: &[9, 22, 23, 25, 27],
-        },
-        TestCase {
-            name: "request_later_blocks_during_reorg_2",
-            chain: local_chain![(0, blocks[&0]), (9, h!("9"))],
-            request_heights: &[10],
-            exp_update_heights: &[0, 9, 10],
-        },
-        TestCase {
-            name: "request_later_and_prev_blocks_during_reorg",
-            chain: local_chain![(0, blocks[&0]), (1, blocks[&1]), (9, h!("9"))],
-            request_heights: &[8, 11],
-            exp_update_heights: &[1, 8, 9, 11],
-        },
-    ];
-
-    for (i, t) in test_cases.into_iter().enumerate() {
-        println!("Case {}: {}", i, t.name);
-        let mut chain = t.chain;
-
-        let update = client
-            .update_local_chain(chain.tip(), t.request_heights.iter().copied())
-            .map_err(|err| {
-                anyhow::format_err!("[{}:{}] `update_local_chain` failed: {}", i, t.name, err)
-            })?;
-
-        let update_blocks = update
-            .tip
-            .iter()
-            .map(|cp| cp.block_id())
-            .collect::<BTreeSet<_>>();
-
-        let exp_update_blocks = t
-            .exp_update_heights
-            .iter()
-            .map(|&height| {
-                let hash = blocks[&height];
-                BlockId { height, hash }
-            })
-            .chain(
-                // Electrs Esplora `get_block` call fetches 10 blocks which is included in the
-                // update
-                blocks
-                    .range(TIP_HEIGHT - 9..)
-                    .map(|(&height, &hash)| BlockId { height, hash }),
-            )
-            .collect::<BTreeSet<_>>();
-
-        assert_eq!(
-            update_blocks, exp_update_blocks,
-            "[{}:{}] unexpected update",
-            i, t.name
-        );
-
-        let _ = chain
-            .apply_update(update)
-            .unwrap_or_else(|err| panic!("[{}:{}] update failed to apply: {}", i, t.name, err));
-
-        // all requested heights must exist in the final chain
-        for height in t.request_heights {
-            let exp_blockhash = blocks.get(height).expect("block must exist in bitcoind");
-            assert_eq!(
-                chain.get(*height).map(|cp| cp.hash()),
-                Some(*exp_blockhash),
-                "[{}:{}] block {}:{} must exist in final chain",
-                i,
-                t.name,
-                height,
-                exp_blockhash
-            );
-        }
-    }
-
-    Ok(())
-}
--- a/crates/file_store/Cargo.toml
+++ b/crates/file_store/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "bdk_file_store"
-version = "0.9.0"
+version = "0.1.0"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/bitcoindevkit/bdk"
@@ -11,7 +11,7 @@ authors = ["Bitcoin Dev Kit Developers"]
 readme = "README.md"

 [dependencies]
-bdk_chain = { path = "../chain", version = "0.12.0", features = [ "serde", "miniscript" ] }
+bdk_chain = { path = "../chain", version = "0.4.0", features = [ "serde", "miniscript" ] }
 bincode = { version = "1" }
 serde = { version = "1", features = ["derive"] }

--- a/crates/file_store/README.md
+++ b/crates/file_store/README.md
@@ -1,9 +1,9 @@
 # BDK File Store

 This is a simple append-only flat file implementation of
-[`Persist`](`bdk_chain::Persist`).
+[`Persist`](`bdk_chain::keychain::persist::Persist`).

-The main structure is [`Store`](`crate::Store`), which can be used with [`bdk`]'s
+The main structure is [`KeychainStore`](`crate::KeychainStore`), which can be used with [`bdk`]'s
 `Wallet` to persist wallet data into a flat file.

 [`bdk`]: https://docs.rs/bdk/latest
--- a/crates/file_store/src/entry_iter.rs
+++ b/crates/file_store/src/entry_iter.rs
@@ -1,108 +0,0 @@
-use bincode::Options;
-use std::{
-    fs::File,
-    io::{self, BufReader, Seek},
-    marker::PhantomData,
-};
-
-use crate::bincode_options;
-
-/// Iterator over entries in a file store.
-///
-/// Reads and returns an entry each time [`next`] is called. If an error occurs while reading the
-/// iterator will yield a `Result::Err(_)` instead and then `None` for the next call to `next`.
-///
-/// [`next`]: Self::next
-pub struct EntryIter<'t, T> {
-    /// Buffered reader around the file
-    db_file: BufReader<&'t mut File>,
-    finished: bool,
-    /// The file position for the first read of `db_file`.
-    start_pos: Option<u64>,
-    types: PhantomData<T>,
-}
-
-impl<'t, T> EntryIter<'t, T> {
-    pub fn new(start_pos: u64, db_file: &'t mut File) -> Self {
-        Self {
-            db_file: BufReader::new(db_file),
-            start_pos: Some(start_pos),
-            finished: false,
-            types: PhantomData,
-        }
-    }
-}
-
-impl<'t, T> Iterator for EntryIter<'t, T>
-where
-    T: serde::de::DeserializeOwned,
-{
-    type Item = Result<T, IterError>;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        if self.finished {
-            return None;
-        }
-        (|| {
-            if let Some(start) = self.start_pos.take() {
-                self.db_file.seek(io::SeekFrom::Start(start))?;
-            }
-
-            let pos_before_read = self.db_file.stream_position()?;
-            match bincode_options().deserialize_from(&mut self.db_file) {
-                Ok(changeset) => Ok(Some(changeset)),
-                Err(e) => {
-                    self.finished = true;
-                    let pos_after_read = self.db_file.stream_position()?;
-                    // allow unexpected EOF if 0 bytes were read
-                    if let bincode::ErrorKind::Io(inner) = &*e {
-                        if inner.kind() == io::ErrorKind::UnexpectedEof
-                            && pos_after_read == pos_before_read
-                        {
-                            return Ok(None);
-                        }
-                    }
-                    self.db_file.seek(io::SeekFrom::Start(pos_before_read))?;
-                    Err(IterError::Bincode(*e))
-                }
-            }
-        })()
-        .transpose()
-    }
-}
-
-impl<'t, T> Drop for EntryIter<'t, T> {
-    fn drop(&mut self) {
-        // This syncs the underlying file's offset with the buffer's position. This way, we
-        // maintain the correct position to start the next read/write.
-        if let Ok(pos) = self.db_file.stream_position() {
-            let _ = self.db_file.get_mut().seek(io::SeekFrom::Start(pos));
-        }
-    }
-}
-
-/// Error type for [`EntryIter`].
-#[derive(Debug)]
-pub enum IterError {
-    /// Failure to read from the file.
-    Io(io::Error),
-    /// Failure to decode data from the file.
-    Bincode(bincode::ErrorKind),
-}
-
-impl core::fmt::Display for IterError {
-    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-        match self {
-            IterError::Io(e) => write!(f, "io error trying to read entry {}", e),
-            IterError::Bincode(e) => write!(f, "bincode error while reading entry {}", e),
-        }
-    }
-}
-
-impl From<io::Error> for IterError {
-    fn from(value: io::Error) -> Self {
-        IterError::Io(value)
-    }
-}
-
-impl std::error::Error for IterError {}
--- a/crates/file_store/src/file_store.rs
+++ b/crates/file_store/src/file_store.rs
@@ -0,0 +1,404 @@
+//! Module for persisting data on disk.
+//!
+//! The star of the show is [`KeychainStore`], which maintains an append-only file of
+//! [`KeychainChangeSet`]s which can be used to restore a [`KeychainTracker`].
+use bdk_chain::{
+    keychain::{KeychainChangeSet, KeychainTracker},
+    sparse_chain,
+};
+use bincode::{DefaultOptions, Options};
+use core::marker::PhantomData;
+use std::{
+    fs::{File, OpenOptions},
+    io::{self, Read, Seek, Write},
+    path::Path,
+};
+
+/// BDK File Store magic bytes length.
+const MAGIC_BYTES_LEN: usize = 12;
+
+/// BDK File Store magic bytes.
+const MAGIC_BYTES: [u8; MAGIC_BYTES_LEN] = [98, 100, 107, 102, 115, 48, 48, 48, 48, 48, 48, 48];
+
+/// Persists an append only list of `KeychainChangeSet<K,P>` to a single file.
+/// [`KeychainChangeSet<K,P>`] record the changes made to a [`KeychainTracker<K,P>`].
+#[derive(Debug)]
+pub struct KeychainStore<K, P> {
+    db_file: File,
+    changeset_type_params: core::marker::PhantomData<(K, P)>,
+}
+
+fn bincode() -> impl bincode::Options {
+    DefaultOptions::new().with_varint_encoding()
+}
+
+impl<K, P> KeychainStore<K, P>
+where
+    K: Ord + Clone + core::fmt::Debug,
+    P: sparse_chain::ChainPosition,
+    KeychainChangeSet<K, P>: serde::Serialize + serde::de::DeserializeOwned,
+{
+    /// Creates a new store from a [`File`].
+    ///
+    /// The file must have been opened with read and write permissions.
+    ///
+    /// [`File`]: std::fs::File
+    pub fn new(mut file: File) -> Result<Self, FileError> {
+        file.rewind()?;
+
+        let mut magic_bytes = [0_u8; MAGIC_BYTES_LEN];
+        file.read_exact(&mut magic_bytes)?;
+
+        if magic_bytes != MAGIC_BYTES {
+            return Err(FileError::InvalidMagicBytes(magic_bytes));
+        }
+
+        Ok(Self {
+            db_file: file,
+            changeset_type_params: Default::default(),
+        })
+    }
+
+    /// Creates or loads a store from `db_path`. If no file exists there, it will be created.
+    pub fn new_from_path<D: AsRef<Path>>(db_path: D) -> Result<Self, FileError> {
+        let already_exists = db_path.as_ref().exists();
+
+        let mut db_file = OpenOptions::new()
+            .read(true)
+            .write(true)
+            .create(true)
+            .open(db_path)?;
+
+        if !already_exists {
+            db_file.write_all(&MAGIC_BYTES)?;
+        }
+
+        Self::new(db_file)
+    }
+
+    /// Iterates over the stored changeset from first to last, changing the seek position at each
+    /// iteration.
+    ///
+    /// The iterator may fail to read an entry and therefore return an error. However, the first time
+    /// it returns an error will be the last. After doing so, the iterator will always yield `None`.
+    ///
+    /// **WARNING**: This method changes the write position in the underlying file. You should
+    /// always iterate over all entries until `None` is returned if you want your next write to go
+    /// at the end; otherwise, you will write over existing entries.
+    pub fn iter_changesets(&mut self) -> Result<EntryIter<'_, KeychainChangeSet<K, P>>, io::Error> {
+        self.db_file
+            .seek(io::SeekFrom::Start(MAGIC_BYTES_LEN as _))?;
+
+        Ok(EntryIter::new(&mut self.db_file))
+    }
+
+    /// Loads all the changesets that have been stored as one giant changeset.
+    ///
+    /// This function returns a tuple of the aggregate changeset and a result that indicates
+    /// whether an error occurred while reading or deserializing one of the entries. If so the
+    /// changeset will consist of all of those it was able to read.
+    ///
+    /// You should usually check the error. In many applications, it may make sense to do a full
+    /// wallet scan with a stop-gap after getting an error, since it is likely that one of the
+    /// changesets it was unable to read changed the derivation indices of the tracker.
+    ///
+    /// **WARNING**: This method changes the write position of the underlying file. The next
+    /// changeset will be written over the erroring entry (or the end of the file if none existed).
+    pub fn aggregate_changeset(&mut self) -> (KeychainChangeSet<K, P>, Result<(), IterError>) {
+        let mut changeset = KeychainChangeSet::default();
+        let result = (|| {
+            let iter_changeset = self.iter_changesets()?;
+            for next_changeset in iter_changeset {
+                changeset.append(next_changeset?);
+            }
+            Ok(())
+        })();
+
+        (changeset, result)
+    }
+
+    /// Reads and applies all the changesets stored sequentially to the tracker, stopping when it fails
+    /// to read the next one.
+    ///
+    /// **WARNING**: This method changes the write position of the underlying file. The next
+    /// changeset will be written over the erroring entry (or the end of the file if none existed).
+    pub fn load_into_keychain_tracker(
+        &mut self,
+        tracker: &mut KeychainTracker<K, P>,
+    ) -> Result<(), IterError> {
+        for changeset in self.iter_changesets()? {
+            tracker.apply_changeset(changeset?)
+        }
+        Ok(())
+    }
+
+    /// Append a new changeset to the file and truncate the file to the end of the appended changeset.
+    ///
+    /// The truncation is to avoid the possibility of having a valid but inconsistent changeset
+    /// directly after the appended changeset.
+    pub fn append_changeset(
+        &mut self,
+        changeset: &KeychainChangeSet<K, P>,
+    ) -> Result<(), io::Error> {
+        if changeset.is_empty() {
+            return Ok(());
+        }
+
+        bincode()
+            .serialize_into(&mut self.db_file, changeset)
+            .map_err(|e| match *e {
+                bincode::ErrorKind::Io(inner) => inner,
+                unexpected_err => panic!("unexpected bincode error: {}", unexpected_err),
+            })?;
+
+        // truncate file after this changeset addition
+        // if this is not done, data after this changeset may represent valid changesets, however
+        // applying those changesets on top of this one may result in an inconsistent state
+        let pos = self.db_file.stream_position()?;
+        self.db_file.set_len(pos)?;
+
+        // We want to make sure that derivation indices changes are written to disk as soon as
+        // possible, so you know about the write failure before you give out the address in the application.
+        if !changeset.derivation_indices.is_empty() {
+            self.db_file.sync_data()?;
+        }
+
+        Ok(())
+    }
+}
+
+/// Error that occurs due to problems encountered with the file.
+#[derive(Debug)]
+pub enum FileError {
+    /// IO error, this may mean that the file is too short.
+    Io(io::Error),
+    /// Magic bytes do not match what is expected.
+    InvalidMagicBytes([u8; MAGIC_BYTES_LEN]),
+}
+
+impl core::fmt::Display for FileError {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        match self {
+            Self::Io(e) => write!(f, "io error trying to read file: {}", e),
+            Self::InvalidMagicBytes(b) => write!(
+                f,
+                "file has invalid magic bytes: expected={:?} got={:?}",
+                MAGIC_BYTES, b
+            ),
+        }
+    }
+}
+
+impl From<io::Error> for FileError {
+    fn from(value: io::Error) -> Self {
+        Self::Io(value)
+    }
+}
+
+impl std::error::Error for FileError {}
+
+/// Error type for [`EntryIter`].
+#[derive(Debug)]
+pub enum IterError {
+    /// Failure to read from the file.
+    Io(io::Error),
+    /// Failure to decode data from the file.
+    Bincode(bincode::ErrorKind),
+}
+
+impl core::fmt::Display for IterError {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        match self {
+            IterError::Io(e) => write!(f, "io error trying to read entry {}", e),
+            IterError::Bincode(e) => write!(f, "bincode error while reading entry {}", e),
+        }
+    }
+}
+
+impl std::error::Error for IterError {}
+
+/// Iterator over entries in a file store.
+///
+/// Reads and returns an entry each time [`next`] is called. If an error occurs while reading the
+/// iterator will yield a `Result::Err(_)` instead and then `None` for the next call to `next`.
+///
+/// [`next`]: Self::next
+pub struct EntryIter<'a, V> {
+    db_file: &'a mut File,
+    types: PhantomData<V>,
+    error_exit: bool,
+}
+
+impl<'a, V> EntryIter<'a, V> {
+    pub fn new(db_file: &'a mut File) -> Self {
+        Self {
+            db_file,
+            types: PhantomData,
+            error_exit: false,
+        }
+    }
+}
+
+impl<'a, V> Iterator for EntryIter<'a, V>
+where
+    V: serde::de::DeserializeOwned,
+{
+    type Item = Result<V, IterError>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let result = (|| {
+            let pos = self.db_file.stream_position()?;
+
+            match bincode().deserialize_from(&mut self.db_file) {
+                Ok(changeset) => Ok(Some(changeset)),
+                Err(e) => {
+                    if let bincode::ErrorKind::Io(inner) = &*e {
+                        if inner.kind() == io::ErrorKind::UnexpectedEof {
+                            let eof = self.db_file.seek(io::SeekFrom::End(0))?;
+                            if pos == eof {
+                                return Ok(None);
+                            }
+                        }
+                    }
+
+                    self.db_file.seek(io::SeekFrom::Start(pos))?;
+                    Err(IterError::Bincode(*e))
+                }
+            }
+        })();
+
+        let result = result.transpose();
+
+        if let Some(Err(_)) = &result {
+            self.error_exit = true;
+        }
+
+        result
+    }
+}
+
+impl From<io::Error> for IterError {
+    fn from(value: io::Error) -> Self {
+        IterError::Io(value)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use bdk_chain::{
+        keychain::{DerivationAdditions, KeychainChangeSet},
+        TxHeight,
+    };
+    use std::{
+        io::{Read, Write},
+        vec::Vec,
+    };
+    use tempfile::NamedTempFile;
+    #[derive(
+        Debug,
+        Clone,
+        Copy,
+        PartialOrd,
+        Ord,
+        PartialEq,
+        Eq,
+        Hash,
+        serde::Serialize,
+        serde::Deserialize,
+    )]
+    enum TestKeychain {
+        External,
+        Internal,
+    }
+
+    impl core::fmt::Display for TestKeychain {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            match self {
+                Self::External => write!(f, "external"),
+                Self::Internal => write!(f, "internal"),
+            }
+        }
+    }
+
+    #[test]
+    fn magic_bytes() {
+        assert_eq!(&MAGIC_BYTES, "bdkfs0000000".as_bytes());
+    }
+
+    #[test]
+    fn new_fails_if_file_is_too_short() {
+        let mut file = NamedTempFile::new().unwrap();
+        file.write_all(&MAGIC_BYTES[..MAGIC_BYTES_LEN - 1])
+            .expect("should write");
+
+        match KeychainStore::<TestKeychain, TxHeight>::new(file.reopen().unwrap()) {
+            Err(FileError::Io(e)) => assert_eq!(e.kind(), std::io::ErrorKind::UnexpectedEof),
+            unexpected => panic!("unexpected result: {:?}", unexpected),
+        };
+    }
+
+    #[test]
+    fn new_fails_if_magic_bytes_are_invalid() {
+        let invalid_magic_bytes = "ldkfs0000000";
+
+        let mut file = NamedTempFile::new().unwrap();
+        file.write_all(invalid_magic_bytes.as_bytes())
+            .expect("should write");
+
+        match KeychainStore::<TestKeychain, TxHeight>::new(file.reopen().unwrap()) {
+            Err(FileError::InvalidMagicBytes(b)) => {
+                assert_eq!(b, invalid_magic_bytes.as_bytes())
+            }
+            unexpected => panic!("unexpected result: {:?}", unexpected),
+        };
+    }
+
+    #[test]
+    fn append_changeset_truncates_invalid_bytes() {
+        // initial data to write to file (magic bytes + invalid data)
+        let mut data = [255_u8; 2000];
+        data[..MAGIC_BYTES_LEN].copy_from_slice(&MAGIC_BYTES);
+
+        let changeset = KeychainChangeSet {
+            derivation_indices: DerivationAdditions(
+                vec![(TestKeychain::External, 42)].into_iter().collect(),
+            ),
+            chain_graph: Default::default(),
+        };
+
+        let mut file = NamedTempFile::new().unwrap();
+        file.write_all(&data).expect("should write");
+
+        let mut store = KeychainStore::<TestKeychain, TxHeight>::new(file.reopen().unwrap())
+            .expect("should open");
+        match store.iter_changesets().expect("seek should succeed").next() {
+            Some(Err(IterError::Bincode(_))) => {}
+            unexpected_res => panic!("unexpected result: {:?}", unexpected_res),
+        }
+
+        store.append_changeset(&changeset).expect("should append");
+
+        drop(store);
+
+        let got_bytes = {
+            let mut buf = Vec::new();
+            file.reopen()
+                .unwrap()
+                .read_to_end(&mut buf)
+                .expect("should read");
+            buf
+        };
+
+        let expected_bytes = {
+            let mut buf = MAGIC_BYTES.to_vec();
+            DefaultOptions::new()
+                .with_varint_encoding()
+                .serialize_into(&mut buf, &changeset)
+                .expect("should encode");
+            buf
+        };
+
+        assert_eq!(got_bytes, expected_bytes);
+    }
+}
--- a/crates/file_store/src/lib.rs
+++ b/crates/file_store/src/lib.rs
@@ -1,42 +1,32 @@
 #![doc = include_str!("../README.md")]
-mod entry_iter;
-mod store;
-use std::io;
+mod file_store;
+use bdk_chain::{
+    keychain::{KeychainChangeSet, KeychainTracker, PersistBackend},
+    sparse_chain::ChainPosition,
+};
+pub use file_store::*;

-use bincode::{DefaultOptions, Options};
-pub use entry_iter::*;
-pub use store::*;
+impl<K, P> PersistBackend<K, P> for KeychainStore<K, P>
+where
+    K: Ord + Clone + core::fmt::Debug,
+    P: ChainPosition,
+    KeychainChangeSet<K, P>: serde::Serialize + serde::de::DeserializeOwned,
+{
+    type WriteError = std::io::Error;

-pub(crate) fn bincode_options() -> impl bincode::Options {
-    DefaultOptions::new().with_varint_encoding()
-}
+    type LoadError = IterError;

-/// Error that occurs due to problems encountered with the file.
-#[derive(Debug)]
-pub enum FileError {
-    /// IO error, this may mean that the file is too short.
-    Io(io::Error),
-    /// Magic bytes do not match what is expected.
-    InvalidMagicBytes { got: Vec<u8>, expected: Vec<u8> },
-}
+    fn append_changeset(
+        &mut self,
+        changeset: &KeychainChangeSet<K, P>,
+    ) -> Result<(), Self::WriteError> {
+        KeychainStore::append_changeset(self, changeset)
+    }

-impl core::fmt::Display for FileError {
-    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-        match self {
-            Self::Io(e) => write!(f, "io error trying to read file: {}", e),
-            Self::InvalidMagicBytes { got, expected } => write!(
-                f,
-                "file has invalid magic bytes: expected={:?} got={:?}",
-                expected, got,
-            ),
-        }
+    fn load_into_keychain_tracker(
+        &mut self,
+        tracker: &mut KeychainTracker<K, P>,
+    ) -> Result<(), Self::LoadError> {
+        KeychainStore::load_into_keychain_tracker(self, tracker)
    }
 }
-
-impl From<io::Error> for FileError {
-    fn from(value: io::Error) -> Self {
-        Self::Io(value)
-    }
-}
-
-impl std::error::Error for FileError {}
--- a/crates/file_store/src/store.rs
+++ b/crates/file_store/src/store.rs
@@ -1,460 +0,0 @@
-use std::{
-    fmt::Debug,
-    fs::{File, OpenOptions},
-    io::{self, Read, Seek, Write},
-    marker::PhantomData,
-    path::Path,
-};
-
-use bdk_chain::{Append, PersistBackend};
-use bincode::Options;
-
-use crate::{bincode_options, EntryIter, FileError, IterError};
-
-/// Persists an append-only list of changesets (`C`) to a single file.
-///
-/// The changesets are the results of altering a tracker implementation (`T`).
-#[derive(Debug)]
-pub struct Store<C> {
-    magic_len: usize,
-    db_file: File,
-    marker: PhantomData<C>,
-}
-
-impl<C> PersistBackend<C> for Store<C>
-where
-    C: Append + serde::Serialize + serde::de::DeserializeOwned,
-{
-    type WriteError = std::io::Error;
-
-    type LoadError = IterError;
-
-    fn write_changes(&mut self, changeset: &C) -> Result<(), Self::WriteError> {
-        self.append_changeset(changeset)
-    }
-
-    fn load_from_persistence(&mut self) -> Result<Option<C>, Self::LoadError> {
-        self.aggregate_changesets().map_err(|e| e.iter_error)
-    }
-}
-
-impl<C> Store<C>
-where
-    C: Append + serde::Serialize + serde::de::DeserializeOwned,
-{
-    /// Create a new [`Store`] file in write-only mode; error if the file exists.
-    ///
-    /// `magic` is the prefixed bytes to write to the new file. This will be checked when opening
-    /// the `Store` in the future with [`open`].
-    ///
-    /// [`open`]: Store::open
-    pub fn create_new<P>(magic: &[u8], file_path: P) -> Result<Self, FileError>
-    where
-        P: AsRef<Path>,
-    {
-        if file_path.as_ref().exists() {
-            // `io::Error` is used instead of a variant on `FileError` because there is already a
-            // nightly-only `File::create_new` method
-            return Err(FileError::Io(io::Error::new(
-                io::ErrorKind::Other,
-                "file already exists",
-            )));
-        }
-        let mut f = OpenOptions::new()
-            .create(true)
-            .read(true)
-            .write(true)
-            .truncate(true)
-            .open(file_path)?;
-        f.write_all(magic)?;
-        Ok(Self {
-            magic_len: magic.len(),
-            db_file: f,
-            marker: Default::default(),
-        })
-    }
-
-    /// Open an existing [`Store`].
-    ///
-    /// Use [`create_new`] to create a new `Store`.
-    ///
-    /// # Errors
-    ///
-    /// If the prefixed bytes of the opened file does not match the provided `magic`, the
-    /// [`FileError::InvalidMagicBytes`] error variant will be returned.
-    ///
-    /// [`create_new`]: Store::create_new
-    pub fn open<P>(magic: &[u8], file_path: P) -> Result<Self, FileError>
-    where
-        P: AsRef<Path>,
-    {
-        let mut f = OpenOptions::new().read(true).write(true).open(file_path)?;
-
-        let mut magic_buf = vec![0_u8; magic.len()];
-        f.read_exact(&mut magic_buf)?;
-        if magic_buf != magic {
-            return Err(FileError::InvalidMagicBytes {
-                got: magic_buf,
-                expected: magic.to_vec(),
-            });
-        }
-
-        Ok(Self {
-            magic_len: magic.len(),
-            db_file: f,
-            marker: Default::default(),
-        })
-    }
-
-    /// Attempt to open existing [`Store`] file; create it if the file is non-existent.
-    ///
-    /// Internally, this calls either [`open`] or [`create_new`].
-    ///
-    /// [`open`]: Store::open
-    /// [`create_new`]: Store::create_new
-    pub fn open_or_create_new<P>(magic: &[u8], file_path: P) -> Result<Self, FileError>
-    where
-        P: AsRef<Path>,
-    {
-        if file_path.as_ref().exists() {
-            Self::open(magic, file_path)
-        } else {
-            Self::create_new(magic, file_path)
-        }
-    }
-
-    /// Iterates over the stored changeset from first to last, changing the seek position at each
-    /// iteration.
-    ///
-    /// The iterator may fail to read an entry and therefore return an error. However, the first time
-    /// it returns an error will be the last. After doing so, the iterator will always yield `None`.
-    ///
-    /// **WARNING**: This method changes the write position in the underlying file. You should
-    /// always iterate over all entries until `None` is returned if you want your next write to go
-    /// at the end; otherwise, you will write over existing entries.
-    pub fn iter_changesets(&mut self) -> EntryIter<C> {
-        EntryIter::new(self.magic_len as u64, &mut self.db_file)
-    }
-
-    /// Loads all the changesets that have been stored as one giant changeset.
-    ///
-    /// This function returns the aggregate changeset, or `None` if nothing was persisted.
-    /// If reading or deserializing any of the entries fails, an error is returned that
-    /// consists of all those it was able to read.
-    ///
-    /// You should usually check the error. In many applications, it may make sense to do a full
-    /// wallet scan with a stop-gap after getting an error, since it is likely that one of the
-    /// changesets it was unable to read changed the derivation indices of the tracker.
-    ///
-    /// **WARNING**: This method changes the write position of the underlying file. The next
-    /// changeset will be written over the erroring entry (or the end of the file if none existed).
-    pub fn aggregate_changesets(&mut self) -> Result<Option<C>, AggregateChangesetsError<C>> {
-        let mut changeset = Option::<C>::None;
-        for next_changeset in self.iter_changesets() {
-            let next_changeset = match next_changeset {
-                Ok(next_changeset) => next_changeset,
-                Err(iter_error) => {
-                    return Err(AggregateChangesetsError {
-                        changeset,
-                        iter_error,
-                    })
-                }
-            };
-            match &mut changeset {
-                Some(changeset) => changeset.append(next_changeset),
-                changeset => *changeset = Some(next_changeset),
-            }
-        }
-        Ok(changeset)
-    }
-
-    /// Append a new changeset to the file and truncate the file to the end of the appended
-    /// changeset.
-    ///
-    /// The truncation is to avoid the possibility of having a valid but inconsistent changeset
-    /// directly after the appended changeset.
-    pub fn append_changeset(&mut self, changeset: &C) -> Result<(), io::Error> {
-        // no need to write anything if changeset is empty
-        if changeset.is_empty() {
-            return Ok(());
-        }
-
-        bincode_options()
-            .serialize_into(&mut self.db_file, changeset)
-            .map_err(|e| match *e {
-                bincode::ErrorKind::Io(inner) => inner,
-                unexpected_err => panic!("unexpected bincode error: {}", unexpected_err),
-            })?;
-
-        // truncate file after this changeset addition
-        // if this is not done, data after this changeset may represent valid changesets, however
-        // applying those changesets on top of this one may result in an inconsistent state
-        let pos = self.db_file.stream_position()?;
-        self.db_file.set_len(pos)?;
-
-        Ok(())
-    }
-}
-
-/// Error type for [`Store::aggregate_changesets`].
-#[derive(Debug)]
-pub struct AggregateChangesetsError<C> {
-    /// The partially-aggregated changeset.
-    pub changeset: Option<C>,
-
-    /// The error returned by [`EntryIter`].
-    pub iter_error: IterError,
-}
-
-impl<C> std::fmt::Display for AggregateChangesetsError<C> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        std::fmt::Display::fmt(&self.iter_error, f)
-    }
-}
-
-impl<C: std::fmt::Debug> std::error::Error for AggregateChangesetsError<C> {}
-
-#[cfg(test)]
-mod test {
-    use super::*;
-
-    use bincode::DefaultOptions;
-    use std::{
-        collections::BTreeSet,
-        io::{Read, Write},
-        vec::Vec,
-    };
-    use tempfile::NamedTempFile;
-
-    const TEST_MAGIC_BYTES_LEN: usize = 12;
-    const TEST_MAGIC_BYTES: [u8; TEST_MAGIC_BYTES_LEN] =
-        [98, 100, 107, 102, 115, 49, 49, 49, 49, 49, 49, 49];
-
-    type TestChangeSet = BTreeSet<String>;
-
-    #[derive(Debug)]
-    struct TestTracker;
-
-    /// Check behavior of [`Store::create_new`] and [`Store::open`].
-    #[test]
-    fn construct_store() {
-        let temp_dir = tempfile::tempdir().unwrap();
-        let file_path = temp_dir.path().join("db_file");
-        let _ = Store::<TestChangeSet>::open(&TEST_MAGIC_BYTES, &file_path)
-            .expect_err("must not open as file does not exist yet");
-        let _ = Store::<TestChangeSet>::create_new(&TEST_MAGIC_BYTES, &file_path)
-            .expect("must create file");
-        // cannot create new as file already exists
-        let _ = Store::<TestChangeSet>::create_new(&TEST_MAGIC_BYTES, &file_path)
-            .expect_err("must fail as file already exists now");
-        let _ = Store::<TestChangeSet>::open(&TEST_MAGIC_BYTES, &file_path)
-            .expect("must open as file exists now");
-    }
-
-    #[test]
-    fn open_or_create_new() {
-        let temp_dir = tempfile::tempdir().unwrap();
-        let file_path = temp_dir.path().join("db_file");
-        let changeset = BTreeSet::from(["hello".to_string(), "world".to_string()]);
-
-        {
-            let mut db = Store::<TestChangeSet>::open_or_create_new(&TEST_MAGIC_BYTES, &file_path)
-                .expect("must create");
-            assert!(file_path.exists());
-            db.append_changeset(&changeset).expect("must succeed");
-        }
-
-        {
-            let mut db = Store::<TestChangeSet>::open_or_create_new(&TEST_MAGIC_BYTES, &file_path)
-                .expect("must recover");
-            let recovered_changeset = db.aggregate_changesets().expect("must succeed");
-            assert_eq!(recovered_changeset, Some(changeset));
-        }
-    }
-
-    #[test]
-    fn new_fails_if_file_is_too_short() {
-        let mut file = NamedTempFile::new().unwrap();
-        file.write_all(&TEST_MAGIC_BYTES[..TEST_MAGIC_BYTES_LEN - 1])
-            .expect("should write");
-
-        match Store::<TestChangeSet>::open(&TEST_MAGIC_BYTES, file.path()) {
-            Err(FileError::Io(e)) => assert_eq!(e.kind(), std::io::ErrorKind::UnexpectedEof),
-            unexpected => panic!("unexpected result: {:?}", unexpected),
-        };
-    }
-
-    #[test]
-    fn new_fails_if_magic_bytes_are_invalid() {
-        let invalid_magic_bytes = "ldkfs0000000";
-
-        let mut file = NamedTempFile::new().unwrap();
-        file.write_all(invalid_magic_bytes.as_bytes())
-            .expect("should write");
-
-        match Store::<TestChangeSet>::open(&TEST_MAGIC_BYTES, file.path()) {
-            Err(FileError::InvalidMagicBytes { got, .. }) => {
-                assert_eq!(got, invalid_magic_bytes.as_bytes())
-            }
-            unexpected => panic!("unexpected result: {:?}", unexpected),
-        };
-    }
-
-    #[test]
-    fn append_changeset_truncates_invalid_bytes() {
-        // initial data to write to file (magic bytes + invalid data)
-        let mut data = [255_u8; 2000];
-        data[..TEST_MAGIC_BYTES_LEN].copy_from_slice(&TEST_MAGIC_BYTES);
-
-        let changeset = TestChangeSet::from(["one".into(), "two".into(), "three!".into()]);
-
-        let mut file = NamedTempFile::new().unwrap();
-        file.write_all(&data).expect("should write");
-
-        let mut store =
-            Store::<TestChangeSet>::open(&TEST_MAGIC_BYTES, file.path()).expect("should open");
-        match store.iter_changesets().next() {
-            Some(Err(IterError::Bincode(_))) => {}
-            unexpected_res => panic!("unexpected result: {:?}", unexpected_res),
-        }
-
-        store.append_changeset(&changeset).expect("should append");
-
-        drop(store);
-
-        let got_bytes = {
-            let mut buf = Vec::new();
-            file.reopen()
-                .unwrap()
-                .read_to_end(&mut buf)
-                .expect("should read");
-            buf
-        };
-
-        let expected_bytes = {
-            let mut buf = TEST_MAGIC_BYTES.to_vec();
-            DefaultOptions::new()
-                .with_varint_encoding()
-                .serialize_into(&mut buf, &changeset)
-                .expect("should encode");
-            buf
-        };
-
-        assert_eq!(got_bytes, expected_bytes);
-    }
-
-    #[test]
-    fn last_write_is_short() {
-        let temp_dir = tempfile::tempdir().unwrap();
-
-        let changesets = [
-            TestChangeSet::from(["1".into()]),
-            TestChangeSet::from(["2".into(), "3".into()]),
-            TestChangeSet::from(["4".into(), "5".into(), "6".into()]),
-        ];
-        let last_changeset = TestChangeSet::from(["7".into(), "8".into(), "9".into()]);
-        let last_changeset_bytes = bincode_options().serialize(&last_changeset).unwrap();
-
-        for short_write_len in 1..last_changeset_bytes.len() - 1 {
-            let file_path = temp_dir.path().join(format!("{}.dat", short_write_len));
-            println!("Test file: {:?}", file_path);
-
-            // simulate creating a file, writing data where the last write is incomplete
-            {
-                let mut db =
-                    Store::<TestChangeSet>::create_new(&TEST_MAGIC_BYTES, &file_path).unwrap();
-                for changeset in &changesets {
-                    db.append_changeset(changeset).unwrap();
-                }
-                // this is the incomplete write
-                db.db_file
-                    .write_all(&last_changeset_bytes[..short_write_len])
-                    .unwrap();
-            }
-
-            // load file again and aggregate changesets
-            // write the last changeset again (this time it succeeds)
-            {
-                let mut db = Store::<TestChangeSet>::open(&TEST_MAGIC_BYTES, &file_path).unwrap();
-                let err = db
-                    .aggregate_changesets()
-                    .expect_err("should return error as last read is short");
-                assert_eq!(
-                    err.changeset,
-                    changesets.iter().cloned().reduce(|mut acc, cs| {
-                        Append::append(&mut acc, cs);
-                        acc
-                    }),
-                    "should recover all changesets that are written in full",
-                );
-                db.db_file.write_all(&last_changeset_bytes).unwrap();
-            }
-
-            // load file again - this time we should successfully aggregate all changesets
-            {
-                let mut db = Store::<TestChangeSet>::open(&TEST_MAGIC_BYTES, &file_path).unwrap();
-                let aggregated_changesets = db
-                    .aggregate_changesets()
-                    .expect("aggregating all changesets should succeed");
-                assert_eq!(
-                    aggregated_changesets,
-                    changesets
-                        .iter()
-                        .cloned()
-                        .chain(core::iter::once(last_changeset.clone()))
-                        .reduce(|mut acc, cs| {
-                            Append::append(&mut acc, cs);
-                            acc
-                        }),
-                    "should recover all changesets",
-                );
-            }
-        }
-    }
-
-    #[test]
-    fn write_after_short_read() {
-        let temp_dir = tempfile::tempdir().unwrap();
-
-        let changesets = (0..20)
-            .map(|n| TestChangeSet::from([format!("{}", n)]))
-            .collect::<Vec<_>>();
-        let last_changeset = TestChangeSet::from(["last".into()]);
-
-        for read_count in 0..changesets.len() {
-            let file_path = temp_dir.path().join(format!("{}.dat", read_count));
-            println!("Test file: {:?}", file_path);
-
-            // First, we create the file with all the changesets!
-            let mut db = Store::<TestChangeSet>::create_new(&TEST_MAGIC_BYTES, &file_path).unwrap();
-            for changeset in &changesets {
-                db.append_changeset(changeset).unwrap();
-            }
-            drop(db);
-
-            // We re-open the file and read `read_count` number of changesets.
-            let mut db = Store::<TestChangeSet>::open(&TEST_MAGIC_BYTES, &file_path).unwrap();
-            let mut exp_aggregation = db
-                .iter_changesets()
-                .take(read_count)
-                .map(|r| r.expect("must read valid changeset"))
-                .fold(TestChangeSet::default(), |mut acc, v| {
-                    Append::append(&mut acc, v);
-                    acc
-                });
-            // We write after a short read.
-            db.write_changes(&last_changeset)
-                .expect("last write must succeed");
-            Append::append(&mut exp_aggregation, last_changeset.clone());
-            drop(db);
-
-            // We open the file again and check whether aggregate changeset is expected.
-            let aggregation = Store::<TestChangeSet>::open(&TEST_MAGIC_BYTES, &file_path)
-                .unwrap()
-                .aggregate_changesets()
-                .expect("must aggregate changesets")
-                .unwrap_or_default();
-            assert_eq!(aggregation, exp_aggregation);
-        }
-    }
-}
--- a/crates/file_store/tests/test_file_store.rs
+++ b/crates/file_store/tests/test_file_store.rs
@@ -0,0 +1 @@
+
--- a/crates/hwi/Cargo.toml
+++ b/crates/hwi/Cargo.toml
@@ -1,13 +0,0 @@
-[package]
-name = "bdk_hwi"
-version = "0.2.0"
-edition = "2021"
-homepage = "https://bitcoindevkit.org"
-repository = "https://github.com/bitcoindevkit/bdk"
-description = "Utilities to use bdk with hardware wallets"
-license = "MIT OR Apache-2.0"
-readme = "README.md"
-
-[dependencies]
-bdk = { path = "../bdk" }
-hwi = { version = "0.8.0", features = [ "miniscript"] }
--- a/crates/hwi/src/lib.rs
+++ b/crates/hwi/src/lib.rs
@@ -1,42 +0,0 @@
-//! HWI Signer
-//!
-//! This crate contains HWISigner, an implementation of a [`TransactionSigner`] to be
-//! used with hardware wallets.
-//! ```no_run
-//! # use bdk::bitcoin::Network;
-//! # use bdk::signer::SignerOrdering;
-//! # use bdk_hwi::HWISigner;
-//! # use bdk::wallet::AddressIndex::New;
-//! # use bdk::{KeychainKind, SignOptions, Wallet};
-//! # use hwi::HWIClient;
-//! # use std::sync::Arc;
-//! #
-//! # fn main() -> Result<(), Box<dyn std::error::Error>> {
-//! let mut devices = HWIClient::enumerate()?;
-//! if devices.is_empty() {
-//!     panic!("No devices found!");
-//! }
-//! let first_device = devices.remove(0)?;
-//! let custom_signer = HWISigner::from_device(&first_device, Network::Testnet.into())?;
-//!
-//! # let mut wallet = Wallet::new_no_persist(
-//! #     "",
-//! #     None,
-//! #     Network::Testnet,
-//! # )?;
-//! #
-//! // Adding the hardware signer to the BDK wallet
-//! wallet.add_signer(
-//!     KeychainKind::External,
-//!     SignerOrdering(200),
-//!     Arc::new(custom_signer),
-//! );
-//!
-//! # Ok(())
-//! # }
-//! ```
-//!
-//! [`TransactionSigner`]: bdk::wallet::signer::TransactionSigner
-
-mod signer;
-pub use signer::*;
--- a/crates/hwi/src/signer.rs
+++ b/crates/hwi/src/signer.rs
@@ -1,94 +0,0 @@
-use bdk::bitcoin::bip32::Fingerprint;
-use bdk::bitcoin::secp256k1::{All, Secp256k1};
-use bdk::bitcoin::Psbt;
-
-use hwi::error::Error;
-use hwi::types::{HWIChain, HWIDevice};
-use hwi::HWIClient;
-
-use bdk::signer::{SignerCommon, SignerError, SignerId, TransactionSigner};
-
-#[derive(Debug)]
-/// Custom signer for Hardware Wallets
-///
-/// This ignores `sign_options` and leaves the decisions up to the hardware wallet.
-pub struct HWISigner {
-    fingerprint: Fingerprint,
-    client: HWIClient,
-}
-
-impl HWISigner {
-    /// Create a instance from the specified device and chain
-    pub fn from_device(device: &HWIDevice, chain: HWIChain) -> Result<HWISigner, Error> {
-        let client = HWIClient::get_client(device, false, chain)?;
-        Ok(HWISigner {
-            fingerprint: device.fingerprint,
-            client,
-        })
-    }
-}
-
-impl SignerCommon for HWISigner {
-    fn id(&self, _secp: &Secp256k1<All>) -> SignerId {
-        SignerId::Fingerprint(self.fingerprint)
-    }
-}
-
-impl TransactionSigner for HWISigner {
-    fn sign_transaction(
-        &self,
-        psbt: &mut Psbt,
-        _sign_options: &bdk::SignOptions,
-        _secp: &Secp256k1<All>,
-    ) -> Result<(), SignerError> {
-        psbt.combine(
-            self.client
-                .sign_tx(psbt)
-                .map_err(|e| {
-                    SignerError::External(format!("While signing with hardware wallet: {}", e))
-                })?
-                .psbt,
-        )
-        .expect("Failed to combine HW signed psbt with passed PSBT");
-        Ok(())
-    }
-}
-
-// TODO: re-enable this once we have the `get_funded_wallet` test util
-// #[cfg(test)]
-// mod tests {
-//     #[test]
-//     fn test_hardware_signer() {
-//         use std::sync::Arc;
-//
-//         use bdk::tests::get_funded_wallet;
-//         use bdk::signer::SignerOrdering;
-//         use bdk::bitcoin::Network;
-//         use crate::HWISigner;
-//         use hwi::HWIClient;
-//
-//         let mut devices = HWIClient::enumerate().unwrap();
-//         if devices.is_empty() {
-//             panic!("No devices found!");
-//         }
-//         let device = devices.remove(0).unwrap();
-//         let client = HWIClient::get_client(&device, true, Network::Regtest.into()).unwrap();
-//         let descriptors = client.get_descriptors::<String>(None).unwrap();
-//         let custom_signer = HWISigner::from_device(&device, Network::Regtest.into()).unwrap();
-//
-//         let (mut wallet, _) = get_funded_wallet(&descriptors.internal[0]);
-//         wallet.add_signer(
-//             bdk::KeychainKind::External,
-//             SignerOrdering(200),
-//             Arc::new(custom_signer),
-//         );
-//
-//         let addr = wallet.get_address(bdk::wallet::AddressIndex::LastUnused);
-//         let mut builder = wallet.build_tx();
-//         builder.drain_to(addr.script_pubkey()).drain_wallet();
-//         let (mut psbt, _) = builder.finish().unwrap();
-//
-//         let finalized = wallet.sign(&mut psbt, Default::default()).unwrap();
-//         assert!(finalized);
-//     }
-// }
--- a/crates/testenv/Cargo.toml
+++ b/crates/testenv/Cargo.toml
@@ -1,24 +0,0 @@
-[package]
-name = "bdk_testenv"
-version = "0.2.0"
-edition = "2021"
-rust-version = "1.63"
-homepage = "https://bitcoindevkit.org"
-repository = "https://github.com/bitcoindevkit/bdk"
-documentation = "https://docs.rs/bdk_testenv"
-description = "Testing framework for BDK chain sources."
-license = "MIT OR Apache-2.0"
-readme = "README.md"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]
-bitcoincore-rpc = { version = "0.18" }
-bdk_chain = { path = "../chain", version = "0.12", default-features = false }
-electrsd = { version= "0.27.1", features = ["bitcoind_25_0", "esplora_a33e97e1", "legacy"] }
-anyhow = { version = "1" }
-
-[features]
-default = ["std"]
-std = ["bdk_chain/std"]
-serde = ["bdk_chain/serde"]
--- a/crates/testenv/README.md
+++ b/crates/testenv/README.md
@@ -1,6 +0,0 @@
-# BDK TestEnv
-
-This crate sets up a regtest environment with a single [`bitcoind`] node
-connected to an [`electrs`] instance. This framework provides the infrastructure
-for testing chain source crates, e.g., [`bdk_chain`], [`bdk_electrum`],
-[`bdk_esplora`], etc.
--- a/crates/testenv/src/lib.rs
+++ b/crates/testenv/src/lib.rs
@@ -1,278 +0,0 @@
-use bdk_chain::bitcoin::{
-    address::NetworkChecked, block::Header, hash_types::TxMerkleNode, hashes::Hash,
-    secp256k1::rand::random, transaction, Address, Amount, Block, BlockHash, CompactTarget,
-    ScriptBuf, ScriptHash, Transaction, TxIn, TxOut, Txid,
-};
-use bitcoincore_rpc::{
-    bitcoincore_rpc_json::{GetBlockTemplateModes, GetBlockTemplateRules},
-    RpcApi,
-};
-use electrsd::electrum_client::ElectrumApi;
-use std::time::Duration;
-
-/// Struct for running a regtest environment with a single `bitcoind` node with an `electrs`
-/// instance connected to it.
-pub struct TestEnv {
-    pub bitcoind: electrsd::bitcoind::BitcoinD,
-    pub electrsd: electrsd::ElectrsD,
-}
-
-impl TestEnv {
-    /// Construct a new [`TestEnv`] instance with default configurations.
-    pub fn new() -> anyhow::Result<Self> {
-        let bitcoind = match std::env::var_os("BITCOIND_EXE") {
-            Some(bitcoind_path) => electrsd::bitcoind::BitcoinD::new(bitcoind_path),
-            None => {
-                let bitcoind_exe = electrsd::bitcoind::downloaded_exe_path()
-                    .expect(
-                "you need to provide an env var BITCOIND_EXE or specify a bitcoind version feature",
-                );
-                electrsd::bitcoind::BitcoinD::with_conf(
-                    bitcoind_exe,
-                    &electrsd::bitcoind::Conf::default(),
-                )
-            }
-        }?;
-
-        let mut electrsd_conf = electrsd::Conf::default();
-        electrsd_conf.http_enabled = true;
-        let electrsd = match std::env::var_os("ELECTRS_EXE") {
-            Some(env_electrs_exe) => {
-                electrsd::ElectrsD::with_conf(env_electrs_exe, &bitcoind, &electrsd_conf)
-            }
-            None => {
-                let electrs_exe = electrsd::downloaded_exe_path()
-                    .expect("electrs version feature must be enabled");
-                electrsd::ElectrsD::with_conf(electrs_exe, &bitcoind, &electrsd_conf)
-            }
-        }?;
-
-        Ok(Self { bitcoind, electrsd })
-    }
-
-    /// Exposes the [`ElectrumApi`] calls from the Electrum client.
-    pub fn electrum_client(&self) -> &impl ElectrumApi {
-        &self.electrsd.client
-    }
-
-    /// Exposes the [`RpcApi`] calls from [`bitcoincore_rpc`].
-    pub fn rpc_client(&self) -> &impl RpcApi {
-        &self.bitcoind.client
-    }
-
-    // Reset `electrsd` so that new blocks can be seen.
-    pub fn reset_electrsd(mut self) -> anyhow::Result<Self> {
-        let mut electrsd_conf = electrsd::Conf::default();
-        electrsd_conf.http_enabled = true;
-        let electrsd = match std::env::var_os("ELECTRS_EXE") {
-            Some(env_electrs_exe) => {
-                electrsd::ElectrsD::with_conf(env_electrs_exe, &self.bitcoind, &electrsd_conf)
-            }
-            None => {
-                let electrs_exe = electrsd::downloaded_exe_path()
-                    .expect("electrs version feature must be enabled");
-                electrsd::ElectrsD::with_conf(electrs_exe, &self.bitcoind, &electrsd_conf)
-            }
-        }?;
-        self.electrsd = electrsd;
-        Ok(self)
-    }
-
-    /// Mine a number of blocks of a given size `count`, which may be specified to a given coinbase
-    /// `address`.
-    pub fn mine_blocks(
-        &self,
-        count: usize,
-        address: Option<Address>,
-    ) -> anyhow::Result<Vec<BlockHash>> {
-        let coinbase_address = match address {
-            Some(address) => address,
-            None => self
-                .bitcoind
-                .client
-                .get_new_address(None, None)?
-                .assume_checked(),
-        };
-        let block_hashes = self
-            .bitcoind
-            .client
-            .generate_to_address(count as _, &coinbase_address)?;
-        Ok(block_hashes)
-    }
-
-    /// Mine a block that is guaranteed to be empty even with transactions in the mempool.
-    pub fn mine_empty_block(&self) -> anyhow::Result<(usize, BlockHash)> {
-        let bt = self.bitcoind.client.get_block_template(
-            GetBlockTemplateModes::Template,
-            &[GetBlockTemplateRules::SegWit],
-            &[],
-        )?;
-
-        let txdata = vec![Transaction {
-            version: transaction::Version::ONE,
-            lock_time: bdk_chain::bitcoin::absolute::LockTime::from_height(0)?,
-            input: vec![TxIn {
-                previous_output: bdk_chain::bitcoin::OutPoint::default(),
-                script_sig: ScriptBuf::builder()
-                    .push_int(bt.height as _)
-                    // randomn number so that re-mining creates unique block
-                    .push_int(random())
-                    .into_script(),
-                sequence: bdk_chain::bitcoin::Sequence::default(),
-                witness: bdk_chain::bitcoin::Witness::new(),
-            }],
-            output: vec![TxOut {
-                value: Amount::ZERO,
-                script_pubkey: ScriptBuf::new_p2sh(&ScriptHash::all_zeros()),
-            }],
-        }];
-
-        let bits: [u8; 4] = bt
-            .bits
-            .clone()
-            .try_into()
-            .expect("rpc provided us with invalid bits");
-
-        let mut block = Block {
-            header: Header {
-                version: bdk_chain::bitcoin::block::Version::default(),
-                prev_blockhash: bt.previous_block_hash,
-                merkle_root: TxMerkleNode::all_zeros(),
-                time: Ord::max(bt.min_time, std::time::UNIX_EPOCH.elapsed()?.as_secs()) as u32,
-                bits: CompactTarget::from_consensus(u32::from_be_bytes(bits)),
-                nonce: 0,
-            },
-            txdata,
-        };
-
-        block.header.merkle_root = block.compute_merkle_root().expect("must compute");
-
-        for nonce in 0..=u32::MAX {
-            block.header.nonce = nonce;
-            if block.header.target().is_met_by(block.block_hash()) {
-                break;
-            }
-        }
-
-        self.bitcoind.client.submit_block(&block)?;
-        Ok((bt.height as usize, block.block_hash()))
-    }
-
-    /// This method waits for the Electrum notification indicating that a new block has been mined.
-    pub fn wait_until_electrum_sees_block(&self) -> anyhow::Result<()> {
-        self.electrsd.client.block_headers_subscribe()?;
-        let mut delay = Duration::from_millis(64);
-
-        loop {
-            self.electrsd.trigger()?;
-            self.electrsd.client.ping()?;
-            if self.electrsd.client.block_headers_pop()?.is_some() {
-                return Ok(());
-            }
-
-            if delay.as_millis() < 512 {
-                delay = delay.mul_f32(2.0);
-            }
-            std::thread::sleep(delay);
-        }
-    }
-
-    /// Invalidate a number of blocks of a given size `count`.
-    pub fn invalidate_blocks(&self, count: usize) -> anyhow::Result<()> {
-        let mut hash = self.bitcoind.client.get_best_block_hash()?;
-        for _ in 0..count {
-            let prev_hash = self
-                .bitcoind
-                .client
-                .get_block_info(&hash)?
-                .previousblockhash;
-            self.bitcoind.client.invalidate_block(&hash)?;
-            match prev_hash {
-                Some(prev_hash) => hash = prev_hash,
-                None => break,
-            }
-        }
-        Ok(())
-    }
-
-    /// Reorg a number of blocks of a given size `count`.
-    /// Refer to [`TestEnv::mine_empty_block`] for more information.
-    pub fn reorg(&self, count: usize) -> anyhow::Result<Vec<BlockHash>> {
-        let start_height = self.bitcoind.client.get_block_count()?;
-        self.invalidate_blocks(count)?;
-
-        let res = self.mine_blocks(count, None);
-        assert_eq!(
-            self.bitcoind.client.get_block_count()?,
-            start_height,
-            "reorg should not result in height change"
-        );
-        res
-    }
-
-    /// Reorg with a number of empty blocks of a given size `count`.
-    pub fn reorg_empty_blocks(&self, count: usize) -> anyhow::Result<Vec<(usize, BlockHash)>> {
-        let start_height = self.bitcoind.client.get_block_count()?;
-        self.invalidate_blocks(count)?;
-
-        let res = (0..count)
-            .map(|_| self.mine_empty_block())
-            .collect::<Result<Vec<_>, _>>()?;
-        assert_eq!(
-            self.bitcoind.client.get_block_count()?,
-            start_height,
-            "reorg should not result in height change"
-        );
-        Ok(res)
-    }
-
-    /// Send a tx of a given `amount` to a given `address`.
-    pub fn send(&self, address: &Address<NetworkChecked>, amount: Amount) -> anyhow::Result<Txid> {
-        let txid = self
-            .bitcoind
-            .client
-            .send_to_address(address, amount, None, None, None, None, None, None)?;
-        Ok(txid)
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use crate::TestEnv;
-    use anyhow::Result;
-    use bitcoincore_rpc::RpcApi;
-
-    /// This checks that reorgs initiated by `bitcoind` is detected by our `electrsd` instance.
-    #[test]
-    fn test_reorg_is_detected_in_electrsd() -> Result<()> {
-        let env = TestEnv::new()?;
-
-        // Mine some blocks.
-        env.mine_blocks(101, None)?;
-        env.wait_until_electrum_sees_block()?;
-        let height = env.bitcoind.client.get_block_count()?;
-        let blocks = (0..=height)
-            .map(|i| env.bitcoind.client.get_block_hash(i))
-            .collect::<Result<Vec<_>, _>>()?;
-
-        // Perform reorg on six blocks.
-        env.reorg(6)?;
-        env.wait_until_electrum_sees_block()?;
-        let reorged_height = env.bitcoind.client.get_block_count()?;
-        let reorged_blocks = (0..=height)
-            .map(|i| env.bitcoind.client.get_block_hash(i))
-            .collect::<Result<Vec<_>, _>>()?;
-
-        assert_eq!(height, reorged_height);
-
-        // Block hashes should not be equal on the six reorged blocks.
-        for (i, (block, reorged_block)) in blocks.iter().zip(reorged_blocks.iter()).enumerate() {
-            match i <= height as usize - 6 {
-                true => assert_eq!(block, reorged_block),
-                false => assert_ne!(block, reorged_block),
-            }
-        }
-
-        Ok(())
-    }
-}
--- a/example-crates/example_bitcoind_rpc_polling/Cargo.toml
+++ b/example-crates/example_bitcoind_rpc_polling/Cargo.toml
@@ -1,12 +0,0 @@
-[package]
-name = "example_bitcoind_rpc_polling"
-version = "0.1.0"
-edition = "2021"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]
-bdk_chain = { path = "../../crates/chain", features = ["serde"] }
-bdk_bitcoind_rpc = { path = "../../crates/bitcoind_rpc" }
-example_cli = { path = "../example_cli" }
-ctrlc = { version = "^2" }
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Steve Myers	747866579d	Add description to file_store cargo metadata	2023-03-20 12:45:33 -05:00
Steve Myers	e6387f8f27	Remove keyword from file_store cargo metadata	2023-03-20 12:37:22 -05:00