Bitcoin Dev Kit — React Native

React Native language bindings for the Bitcoin Development Kit.

The code in this repository is mostly comprised of:

• Build tools and workflows
• CI workflows
• Tests
• Docs

The core Rust code that is exposed to the React Native language bindings actually resides in the bdk-ffi repository. This repo pulls it in as a submodule.

Notes for developers

See the docs at https://jhugman.github.io/uniffi-bindgen-react-native/guides/rn/getting-started.html for more advanced information on how to build this library.

To build the library and start testing locally, you must have:

• The Rust toolchain installed on your machine
• Set the default Rust toolchain to 1.90.0 (currently Rust stable)
• The just cli tool
• Initiated the submodule (just submodule-init)
• Installed your Rust compilation targets

Building the library and running the example wallet

The example/ directory contains a full-featured example wallet app that uses workspaces for development.

# Clone the repo and install prerequisites
git clone [email protected]:bitcoindevkit/bdk-react-native.git
cargo install cargo-ndk
yarn install

# Install compilation targets, for example:
rustup target add aarch64-linux-android aarch64-apple-ios aarch64-apple-ios-sim

# Build the library
just rename-library
just build-android

# Start an Android emulator and run the example app
yarn example start    # In terminal 1
yarn example android  # In terminal 2

Running the IntegrationTestingApp

The IntegrationTestingApp/ directory contains a standalone test app that uses the library as a tarball dependency (similar to how end-users would consume it). This app is not part of the workspace and is completely decoupled from the library development. You can use the following workflow to run the tests locally on an Android emulator, or to develop features on the library by first making changes to the local bdk-ffi repository, and then running through the workflow with new/modified tests.

# First, build and package the library
just build-android
npm pack  # Creates bdk-rn-0.1.0.tgz

# Install dependencies in the IntegrationTestingApp
cd IntegrationTestingApp
npm install
npm install ../bdk-rn-0.1.0-next.tgz

# To see tests results in your shell, run this prior to starting the app
adb logcat -c && adb logcat -s ReactNativeJS | tee tests.log

# Run the app
npm run android  # or npm run ios

Notes

1. The cargo-ndk library removed the --no-strip argument and this is creating a build error when using the latest release of uniffi-bindgen-react-native (0.29.3-1). We are currently building using a commit on their main branch which contains the patch. See the package.json file.
2. For some reason the example app doesn't work on my Pixel 8 API 35 emulator, but does work on the Pixel 5 API 31 and the Pixel 9 API 36. If you get a red banner at the top of the app when launching saying Unable to load script... and asking you to start Metro, try the example in a different emulator!