bdk-ffi/bdk-jvm

bdk-jvm

This project builds a .jar package for the JVM platform that provide Kotlin language bindings for the bdk library. The Kotlin language bindings are created by the bdk-ffi project which is included in the root of this repository.

How to Use

To use the Kotlin language bindings for bdk in your JVM project add the following to your gradle dependencies:

repositories {
    mavenCentral()
}

dependencies {
  implementation("org.bitcoindevkit:bdk-jvm:<version>")
}

You may then import and use the org.bitcoindevkit library in your Kotlin code like so. Note that this example is for the 0.30.0 release. For examples of the 1.0 API in the alpha releases, take a look at the tests here.

import org.bitcoindevkit.*

// ...

val externalDescriptor = Descriptor("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)", Network.TESTNET)
val internalDescriptor = Descriptor("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)", Network.TESTNET)

val databaseConfig = DatabaseConfig.Memory

val blockchainConfig = BlockchainConfig.Electrum(
    ElectrumConfig("ssl://electrum.blockstream.info:60002", null, 5u, null, 10u, true)
)
val wallet = Wallet(externalDescriptor, internalDescriptor, Network.TESTNET, databaseConfig, blockchainConfig)
val newAddress = wallet.getAddress(AddressIndex.LastUnused)

Snapshot releases

To use a snapshot release, specify the snapshot repository url in the repositories block and use the snapshot version in the dependencies block:

repositories {
    maven("https://s01.oss.sonatype.org/content/repositories/snapshots/")
}

dependencies { 
    implementation("org.bitcoindevkit:bdk-jvm:<version-SNAPSHOT>")
}

Example Projects

• Tatooine Faucet

How to build

Note that Kotlin version 1.6.10 or later is required to build the library.

1. Install JDK 11. It must be version 11 (not 17), otherwise it won't build. For example, with SDKMAN!:

curl -s "https://get.sdkman.io" | bash
source "$HOME/.sdkman/bin/sdkman-init.sh"
sdk install java 11.0.19-tem

2. Install Rust (note that we are currently building using Rust 1.73.0):

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup default 1.73.0

3. Clone this repository.

git clone https://github.com/bitcoindevkit/bdk-ffi

4. If building on macOS install required intel and m1 jvm targets

rustup target add x86_64-apple-darwin aarch64-apple-darwin

5. Build kotlin bindings

./gradlew buildJvmLib

How to publish to your local Maven repo

cd bdk-jvm
./gradlew publishToMavenLocal --exclude-task signMavenPublication

Note that the commands assume you don't need the local libraries to be signed. If you do wish to sign them, simply set your ~/.gradle/gradle.properties signing key values like so:

signing.gnupg.keyName=<YOUR_GNUPG_ID>
signing.gnupg.passphrase=<YOUR_GNUPG_PASSPHRASE>

and use the publishToMavenLocal task without excluding the signing task:

./gradlew publishToMavenLocal

Known issues

JNA dependency

Depending on the JVM version you use, you might not have the JNA dependency on your classpath. The exception thrown will be

class file for com.sun.jna.Pointer not found

The solution is to add JNA as a dependency like so:

dependencies {
    // ...
    implementation("net.java.dev.jna:jna:5.12.1")
}