# bdk-android This project builds an .aar package for the Android 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 Android project add the following to your gradle dependencies: ```kotlin repositories { mavenCentral() } dependencies { implementation("org.bitcoindevkit:bdk-android:") } ``` ### 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: ```kotlin repositories { maven("https://s01.oss.sonatype.org/content/repositories/snapshots/") } dependencies { implementation("org.bitcoindevkit:bdk-android:") } ``` ### Example Projects * [bdk-kotlin-example-wallet](https://github.com/bitcoindevkit/bdk-kotlin-example-wallet) * [Devkit Wallet](https://github.com/thunderbiscuit/devkit-wallet) * [Padawan Wallet](https://github.com/thunderbiscuit/padawan-wallet) ### How to build _Note that Kotlin version `1.9.23` or later is required to build the library._ 1. Clone this repository. ```shell git clone https://github.com/bitcoindevkit/bdk-ffi ``` 2. Follow the "General" bdk-ffi ["Getting Started (Developer)"] instructions. 3. Install Rust (note that we are currently building using Rust 1.73.0): ```shell curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh rustup default 1.73.0 ``` 4. Install required targets ```sh rustup target add x86_64-linux-android aarch64-linux-android armv7-linux-androideabi ``` 5. Install Android SDK and Build-Tools for API level 30+ 6. Setup `$ANDROID_SDK_ROOT` and `$ANDROID_NDK_ROOT` path variables (which are required by the build tool), for example (note that currently, NDK version 25.2.9519653 or above is required): ```shell export ANDROID_SDK_ROOT=~/Android/Sdk export ANDROID_NDK_ROOT=$ANDROID_SDK_ROOT/ndk/25.2.9519653 ``` 7. Build kotlin bindings ```sh # build Android library cd bdk-android ./gradlew buildAndroidLib ``` 1. Start android emulator and run tests ```sh ./gradlew connectedAndroidTest ``` ## How to publish to your local Maven repo ```shell cd bdk-android ./gradlew publishToMavenLocal -P localBuild ``` 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: ```properties signing.gnupg.keyName= signing.gnupg.passphrase= ``` and use the `publishToMavenLocal` task without the `localBuild` flag: ```shell ./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 ```shell class file for com.sun.jna.Pointer not found ``` The solution is to add JNA as a dependency like so: ```kotlin dependencies { // ... implementation("net.java.dev.jna:jna:5.12.1") } ``` ### x86 emulators For some older versions of macOS, Android Studio will recommend users install the x86 version of the emulator by default. This will not work with the bdk-android library, as we do not support 32-bit architectures. Make sure you install an x86_64 emulator to work with bdk-android. [`bdk`]: https://github.com/bitcoindevkit/bdk [`bdk-ffi`]: https://github.com/bitcoindevkit/bdk-ffi