bdk-kotlin

This project builds .jar and .aar packages for the jvm and android platforms that provide Kotlin language bindings for the bdk library. The Kotlin language bindings are created by the bdk-ffi project which is included as a git submodule of this repository.

How to Use

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

repositories {
    mavenCentral()
}

dependencies {
  
  // for jvm
  implementation 'org.bitcoindevkit:bdk-jvm:<version>'
  // OR for android
  implementation 'org.bitcoindevkit:bdk-android:<version>'
  
}

You may then import and use the org.bitcoindevkit library in your Kotlin code. For example:

import org.bitcoindevkit.*

// ...

val externalDescriptor = "wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)"
val internalDescriptor = "wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)"

val databaseConfig = DatabaseConfig.Memory

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

Example Projects

`bdk-android`

`bdk-jvm`

Tatooine Faucet

How to build

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

Clone this repository and initialize and update its bdk-ffi submodule.

git clone https://github.com/bitcoindevkit/bdk-kotlin
git submodule update --init

Follow the "General" bdk-ffi "Getting Started (Developer)" instructions.
If building on MacOS install required intel and m1 jvm targets

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

Install required targets

rustup target add x86_64-linux-android aarch64-linux-android armv7-linux-androideabi

Install Android SDK and Build-Tools for API level 30+
Setup $ANDROID_SDK_ROOT and $ANDROID_NDK_ROOT path variables (which are required by the build tool), for example (NDK major version 21 is required):

export ANDROID_SDK_ROOT=~/Android/Sdk
export ANDROID_NDK_ROOT=$ANDROID_SDK_ROOT/ndk/21.<NDK_VERSION>

Build kotlin bindings

# build JVM library
./gradlew :jvm:buildJvmLib

# build Android library
./gradlew :android:buildAndroidLib

Start android emulator (must be x86_64) and run tests

./gradlew connectedAndroidTest

How to publish

Publish to your local maven repo

Set your ~/.gradle/gradle.properties signing key values

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

Publish

./gradlew :jvm:publishToMavenLocal
./gradlew :android:publishToMavenLocal

Note that if you do not have gpg keys set up to sign the publication, the task will fail. If you wish to publish to your local Maven repository for local testing without signing the release, you can do so by excluding the signMavenPublication subtask like so:

./gradlew :jvm:publishToMavenLocal --exclude-task signMavenPublication
./gradlew :android:publishToMavenLocal --exclude-task signMavenPublication

Publish to maven central with Gradle Nexus Publish Plugin (project maintainers only)

Set your ~/.gradle/gradle.properties signing key values and SONATYPE login

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

ossrhUserName=<YOUR_SONATYPE_USERNAME>
ossrhPassword=<YOUR_SONATYPE_PASSWORD>

Publish

./gradlew :jvm:publishToSonatype closeAndReleaseSonatypeStagingRepository
./gradlew :android:publishToSonatype closeAndReleaseSonatypeStagingRepository

kaiwolfram / bdk-kotlin