File Explorer

1# Class: WebSocket2 3> ⚠️ Warning: the WebSocket API is experimental.4 5Extends: [`EventTarget`](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget)6 7The WebSocket object provides a way to manage a WebSocket connection to a server, allowing bidirectional communication. The API follows the [WebSocket spec](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket) and [RFC 6455](https://datatracker.ietf.org/doc/html/rfc6455).8 9## `new WebSocket(url[, protocol])`10 11Arguments:12 13* **url** `URL | string` - The url's protocol *must* be `ws` or `wss`.14* **protocol** `string | string[] | WebSocketInit` (optional) - Subprotocol(s) to request the server use, or a [`Dispatcher`](./Dispatcher.md).15 16### WebSocketInit17 18When passing an object as the second argument, the following options are available:19 20* **protocols** `string | string[]` (optional) - Subprotocol(s) to request the server use.21* **dispatcher** `Dispatcher` (optional) - A custom [`Dispatcher`](/docs/docs/api/Dispatcher.md) to use for the connection.22* **headers** `HeadersInit` (optional) - Custom headers to include in the WebSocket handshake request.23 24### Example:25 26This example will not work in browsers or other platforms that don't allow passing an object.27 28```mjs29import { WebSocket, ProxyAgent } from 'undici'30 31const proxyAgent = new ProxyAgent('my.proxy.server')32 33const ws = new WebSocket('wss://echo.websocket.events', {34  dispatcher: proxyAgent,35  protocols: ['echo', 'chat']36})37```38 39If you do not need a custom Dispatcher, it's recommended to use the following pattern:40 41```mjs42import { WebSocket } from 'undici'43 44const ws = new WebSocket('wss://echo.websocket.events', ['echo', 'chat'])45```46 47## Read More48 49- [MDN - WebSocket](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket)50- [The WebSocket Specification](https://www.rfc-editor.org/rfc/rfc6455)51- [The WHATWG WebSocket Specification](https://websockets.spec.whatwg.org/)52