clightningjs

C-lightning plugin library for nodejs

Installation

npm install clightningjs --save

Usage

Summary

• Methods
• Startup options
• Notifications
• Hooks
• Advanced usage
• Changelog

Methods

A method should take a JSON array as parameter and return either a valid JSON-encodable value :

#!/usr/bin/env node
const Plugin = require('clightningjs');
 
const helloPlugin = new Plugin();
 
function sayHello(params) {
  if (!params || params.length === 0) {
    return 'Hello world';
  } else {
    return 'Hello ' + params[0];
  }
}
 
helloPlugin.addMethod('hello', sayHello, 'name', 'If you launch me, I\'ll great you !');
helloPlugin.start();

Or a promise :

#!/usr/bin/env node
const Plugin = require('clightningjs');
 
const helloPlugin = new Plugin();
 
async function sayBye(params) {
  return Promise.resolve('Bye bye');
}
 
helloPlugin.addMethod('bye', sayBye, '', 'If you launch me, I\'ll say good bye');
helloPlugin.start();

Startup options

You can add a startup option to lightningd and make a method behave depending on it:

#!/usr/bin/env node
const Plugin = require('clightningjs');
 
const helloPlugin = new Plugin();
 
async function sayBye(params) {
  return Promise.resolve('Bye bye ' + helloPlugin.options['byename'].value);
}
 
helloPlugin.addOption('byename', 'continuum', 'The name of whow I should say bye to', 'string');
helloPlugin.addMethod('bye', sayBye, '', 'If you launch me, I\'ll say good bye');
helloPlugin.start();

Notifications subscription

You can subscribe to lightningd notifications, the plugin will emit events upon their reception :

#!/usr/bin/env node
const fs = require('fs');
const Plugin = require('clightningjs');
 
const listenPlugin = new Plugin();
 
listenPlugin.subscribe('warning');
listenPlugin.notifications.warning.on('warning', (params) => {
  fs.writeFile('log', params.warning.log, () => {});
});
 
listenPlugin.start();

Hooks subscription

You can subscribe to lightningd hooks :

#!/usr/bin/env node
const fs = require('fs');
const Plugin = require('clightningjs');
 
const dbBackup = new Plugin();
 
function useLessBackup(params) {
  fs.writeFile('logDb', params.writes, () => {});
  return true;
}
 
dbBackup.addHook('db_write', useLessBackup);
dbBackup.start();

More

You can restrict RPC control over your plugin with

// myStaticPlugin cannot be stopped by RPC
const myStaticPlugin = new Plugin({ dynamic: false });

You can log to lightningd logs with myPlugin.log(message, logLevel), with the level defaulting to 'info'.

You can do some stuff at initialization (just before responding to the init message):

const myPlugin = new Plugin();
// "params" contains the params passed by `lightningd` along with the `init` message
myPlugin.onInit= function (params) {
    myPlugin.log('I\'m going to be initialized !!');
};

You can return a promise to a hook or a RPC method callback. This allows to not restrain the context of an RPC method or a hook result only to the registered callback. Here is an example from test/hodl.js which, well, hodl an HTLC..

const myWonderfulPlugin = new Plugin({dynamic: true});
myWonderfulPlugin.relasedHtlc = new EventEmitter();
 
myWonderfulPlugin.addHook('htlc_accepted', () => {
  myWonderfulPlugin.log('Ok, I won\'t release the HTLC, but will return!');
  return new Promise((resolve, reject) => {
    myWonderfulPlugin.relasedHtlc.on('released', () => {
      myWonderfulPlugin.log('Resolved');
      resolve({'result': 'continue'});
    });
  });
});
 
function releaseHtlc(params) {
  myWonderfulPlugin.log('Ok, finally I will release the HTLC and all the stuck liquidity.');
  myWonderfulPlugin.relasedHtlc.emit('released');
  return "OK";
}
 
myWonderfulPlugin.addMethod('releasehtlc', releaseHtlc, '', 'release an HTLC', '.');
 
myWonderfulPlugin.start();

More about C-lightning plugins

You can find more about C-lightning plugins :

• On the lightningd/plugins repo
• On the doc
• On the C-lightning repo

Plugins in other languages :

• Python
• C
• Go
• C++

LICENCE

BSD 3-clause clear