react-native-ldk

⚠️ This is pre-alpha software and not suitable for production apps yet.

Description

This library hopes to simplify the process of adding Lightning via LDK to any React-Native app.

Getting started

yarn add @synonymdev/react-native-ldk
#or
npm i -S @synonymdev/react-native-ldk

iOS installation

cd ios && pod install && cd ../

Android installation

1. Add the following line to dependencies in /android/app/build.gradle

   dependencies {
     //...
     implementation files("../../node_modules/@synonymdev/react-native-ldk/android/libs/LDK-release.aar") // <- this
   }

2. Ensure minSdkVersion is set to at least 24 in /android/build.gradle

Development

Android

• Open lib/android in Android Studio
• To enable documentation for the LDK code, follow this guide: How to attach JavaDoc to the library in Android Studio, ie.:
  1. Switch to Project view in the Project browser tool window
  2. Expand External Libraries
  3. Right click on Gradle: ./libs/LDK-release.aar then Library Properties…
  4. Tap the ➕ button and select the ./lib/android/libs/ldk-java-javadoc.jar file
  5. In the popup that appears select JavaDocs and tap OK then OK again

Version Bump

# apply your changes
cd example
yarn reinstall # bump versions package.json & podfile
cd ../
# copy version from `./lib/package.json` to `backup-server/package.json`

Running example app

See also ./example/README.md

# Build dist files
git clone https://github.com/synonymdev/react-native-ldk.git
cd react-native-ldk/lib/ && yarn install && yarn build && cd ../

cd example/ && yarn install && yarn rn-setup

yarn ios
# or
yarn android

Update config to match your local setup

In constants.ts update peers.lnd if you're using Polar locally.

Example for Android

//  export const peers = {
// 	lnd: {
    pubKey:
      '_033f4d3032ce7f54224f4bd9747b50b7cd72074a859758e40e1ca46ffa79a34324_',
    address: '10.0.2.2',
    port: 9737,
// },

Notes

• It is important to not mix and match account names and seeds when starting LDK. Doing so can result in a corrupt save.

Using zero conf channels

Channels needs to be manually accepted but this is handled by channel-manager.ts if counterparty is in our trusted peer list.

const userConfig: TUserConfig = {
   channel_handshake_config: {
   	announced_channel: false,
   	minimum_depth: 1,
   	max_htlc_value_in_flight_percent_of_channel: 100,
   	negotiate_anchors_zero_fee_htlc_tx: true, //Required for zero conf
   },
   manually_accept_inbound_channels: true, //Required for zero conf
   accept_inbound_channels: true,
};

When starting LDK, provide a list of node public keys from which you are willing to accept zero-confirmation channels.

const lmStart = await lm.start(
  ...
  trustedZeroConfPeers: ['03fc8877790430d7fb29e7bcf6b8bbfa3050e5e89189e27f97300e8a1e9ce589a3']

From LND update your conf as specified here and open with these params: lncli openchannel --node_key=03c6b2081d6f333fe3a9655cdb864be7b6b46c8648188a44b6a412e41b63a43272 --local_amt=200000 --push_amt=50000 --private=true --zero_conf --channel_type=anchors

Upgrading LDK

• Use latest LDK-release.aar from ldk-garbagecollected and place in lib/android/libs.
• Use latest LDKFramework.xcframework from ldk-swift and place in lib/ios.
  • To get pod install working you might have to open the LDKFramework.xcframework directory, delete non ios frameworks and remove all references to deleted frameworks inside LDKFramework.xcframework/Info.plist.
• Update Swift and Kotlin code if there are any breaking changes.

Testing

Tests are implemented using mocha-remote. To run tests at first you need to install docker and start tesing regtest enviroment using docker-compose:

cd example
docker-compose up

Then to run tests open two terminals and execute the following commands:

# Terminal 1
cd example
npm run start

# Terminal 2
cd example
npm run test:mocha

How to test your code

Because it's a native module, you need to mock this package.

The package provides a default mock you may use in your __mocks__/@synonymdev/react-native-ldk.js or jest.setup.js.

import * as mockLDK from '@synonymdev/react-native-ldk/dist/mock';

jest.mock('@synonymdev/react-native-ldk', () => mockLDK);