@electrum-cash/network

Introduction

@electrum-cash/network is a lightweight JavaScript library that lets you connect Electrum servers.

It offers encrypted connections by default, performs the expected protocol version negotiation and automatically keeps your connection alive until your close it.

Installation

Install the library with NPM:

# npm install @electrum-cash/network

Usage

Usage with NodeJS

Before you can use the library you need to include it in your project.

// Load the electrum library.
const { ElectrumClient } = require('@electrum-cash/network');

Usage on Web

To use the library on the web, use the ESM import syntax and include the ElectrumTransport import:

// Load the electrum library.
import { ElectrumClient, ElectrumTransport } from '@electrum-cash/network';

Connecting to a server

After you have imported the library you need to initialize and connect the client by configuring your application identifier and protocol version.

// Initialize an electrum client.
const electrumClient = new ElectrumClient('Electrum client example', '1.4.1', 'bch.imaginary.cash');

// Wait for the client to connect
await electrumClient.connect();

To connect to an electrum server from a web browser, use the ElectrumTransport import to use the WSS port and scheme:

const electrumClient = new ElectrumClient(
	'Electrum client example', '1.4.1', 'bch.imaginary.cash',
	ElectrumTransport.WSS.Port, ElectrumTransport.WSS.Scheme
);

Request information

Once your ElectrumClient is connected and ready, you can call methods:

For a list of methods you can use, refer to the Electrum Cash documentation.

// Declare an example transaction ID.
const transactionID = '4db095f34d632a4daf942142c291f1f2abb5ba2e1ccac919d85bdc2f671fb251';

// Request the full transaction hex for the transaction ID.
const transactionHex = await electrumClient.request('blockchain.transaction.get', transactionID);

// Print out the transaction hex.
console.log(transactionHex);

Subscribe to notifications.

Once your ElectrumClient is connected and ready, you can set up subscriptions to get notifications on events:

For a list of methods you can subscribe to, refer to the Electrum Cash documentation.

// Set up a callback function to handle new blocks.
const handleNotifications = function(data)
{
	if(data.method === 'blockchain.headers.subscribe')
	{
		// Print out the block information.
		// {
		// 	jsonrpc: '2.0',
		// 	method: 'blockchain.headers.subscribe',
		// 	params:
		// 	[
		// 		{
		// 		height: 797111,
		// 		hex: '002001202a6b1367f68201ad957e95bec9bda3f132ca2fcb75c0c000000000000000000074befba60bd8615d87ddb636aa99bc032cec8db3adb0d915d45391bc811c1e9ceacf89647a60051819a79559'
		// 		}
		// 	]
		// }
		console.log(data);
	}
}

// Listen for notifications.
electrumClient.on('notification', handleNotifications);

// Set up a subscription for new block headers.
await electrumClient.subscribe('blockchain.headers.subscribe');

Shutting down

When you're done and don't want to be connected anymore you can disconnect the server:

// Close the connection.
await electrumClient.disconnect();

Documentation

For a complete list of methods and parameters, read the API documentation.

Support and communication

If you need help with how to use the library or just want to talk about electrum-cash, you can find us on Telegram and Discord.

Notes

The keep-alive functionality of this library only works when the protocol version is 1.2 or higher.