class WebSocketServer

Supported only in the v8 engine. Introduced in Max v9.2.0.

A WebSocket server.

Supports plain ws:// server sockets only; WSS/certificate configuration is not exposed. Use { noServer: true } together with an http/https server upgrade listener to accept ws:///wss:// upgrades on an existing server.

Example

const wss = new WebSocketServer({ port: 8081, host: "127.0.0.1" });
wss.on("connection", (ws) => {
  ws.on("message", (event) => ws.send(event.data));
});

Index

Constructors

new WebSocketServer(options, callback)

Methods

close(callback)
emit(type, args)
handleUpgrade(req, socket, head, callback)
listen(optionsOrPort, callback)
off(type, listener)
on(type, listener)
once(type, listener)

new WebSocketServer(options, callback)

new WebSocketServer(
  options?: {
    port?: number;
    host?: string;
    noServer?: boolean;
    protocols?: string | string[];
    selectProtocol?: (req: any, offeredProtocols: string[]) => string;
  },
  callback?: (ws: WebSocketConnection, req: any) => void,
);

Constructs a new instance of the WebSocketServer class

Parameter	Type	Description
optional options	object	server options. `noServer: true` creates a server with no acceptor for use with `handleUpgrade`. `selectProtocol(req, offered)` chooses a subprotocol during upgrade handling. optional options.port number optional options.host string optional options.noServer boolean optional options.protocols string \| string[] optional options.selectProtocol (req: any, offeredProtocols: string[]) => string
optional callback	(ws: WebSocketConnection, req: any) => void	an optional `connection` listener.

close(callback)

Stops the server.

close(callback?: () => void): void;

Name	Type	Description
optional callback	() => void

emit(type, args)

Emits an event to registered listeners.

emit(type: string, ...args: any[]): boolean;

Name	Type	Description
type	string
args	any[]
Return Value	boolean

handleUpgrade(req, socket, head, callback)

Completes a WebSocket handshake on an upgrade socket obtained from an HTTP server upgrade event.

handleUpgrade(
  req: any,
  socket: any,
  head: any,
  callback: (ws: WebSocketConnection) => void,
): void;

Name	Type	Description
req	any
socket	any
head	any
callback	(ws: WebSocketConnection) => void

listen(optionsOrPort, callback)

Begins listening (when not in noServer mode).

listen(
  optionsOrPort: number | { port?: number; host?: string },
  callback?: () => void,
): void;

Name	Type	Description
optionsOrPort	number \| { port?: number; host?: string }
optional callback	() => void

off(type, listener)

Removes an event listener.

off(type: string, listener: (...args: any[]) => void): this;

Name	Type	Description
type	string
listener	(...args: any[]) => void
Return Value	this

on(type, listener)

Registers an event listener (listening, connection, close, error).

on(type: string, listener: (...args: any[]) => void): this;

Name	Type	Description
type	string
listener	(...args: any[]) => void
Return Value	this

once(type, listener)

Registers a one-shot event listener.

once(type: string, listener: (...args: any[]) => void): this;

Name	Type	Description
type	string
listener	(...args: any[]) => void
Return Value	this