1# Class: WebSocket
2
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### Example:
17
18This example will not work in browsers or other platforms that don't allow passing an object.
19
20```mjs
21import { WebSocket, ProxyAgent } from 'undici'
22
23const proxyAgent = new ProxyAgent('my.proxy.server')
24
25const ws = new WebSocket('wss://echo.websocket.events', {
26  dispatcher: proxyAgent,
27  protocols: ['echo', 'chat']
28})
29```
30
31If you do not need a custom Dispatcher, it's recommended to use the following pattern:
32
33```mjs
34import { WebSocket } from 'undici'
35
36const ws = new WebSocket('wss://echo.websocket.events', ['echo', 'chat'])
37```
38
39## Read More
40
41- [MDN - WebSocket](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket)
42- [The WebSocket Specification](https://www.rfc-editor.org/rfc/rfc6455)
43- [The WHATWG WebSocket Specification](https://websockets.spec.whatwg.org/)
44