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Channel (WebSocket, Rpc)

Channel is the lowest purest object you can use to interact with the network. Channel represent implementation of the Starknet specification in it's strictly defined form.

WebSocket Channel​

WebSocket channel provide convenient way to establish websocket connection to the Starknet RPC Node.

Ensure that you are using node supporting the required Rpc spec >= v0.8.0. Details regarding Starknet Nodes and supported RPC versions could be found on each node github/page.

Websocket Channel implements specification methods defined by @starknet-io/types-js

Import​

import { WebSocketChannel } from 'starknet';

Create instance​

// crete new ws channel
const webSocketChannel = new WebSocketChannel({
  nodeUrl: 'wss://sepolia-pathfinder-rpc.server.io/rpc/v0_8',
});

// ensure ws channel is open
await webSocketChannel.waitForConnection();

// ... use webSocketChannel

Usage​

// subscribe to event
await webSocketChannel.subscribeNewHeads();

// define listener method
webSocketChannel.onNewHeads = async function (data) {
  //... on event new head data
};

Available subscriptions are:

  • subscribeNewHeads
  • subscribeEvents
  • subscribeTransactionStatus
  • subscribePendingTransaction

Complete API can be found on websocket API section

Unmanaged subscriptions​

Websocket channel manage subscription id, but it is limited to one subscription per event type. If you need multiple subscriptions of the same type use *Unmanaged methods and handle subscriptions manually.