WebSocketServeOptions

interface WebSocketServeOptions<WebSocketDataType = undefined>

• development?: boolean | { hmr: boolean }

  Render contextual errors? This enables bun's error page

• error?: (this: Server, error: ErrorLike) => void | Promise<void> | Response | Promise<Response>
• hostname?: string

  What hostname should the server listen on?

  "127.0.0.1" // Only listen locally
  
• id?: null | string

  Uniquely identify a server instance with an ID

  When bun is started with the --hot flag

  This string will be used to hot reload the server without interrupting pending requests or websockets. If not provided, a value will be generated. To disable hot reloading, set this value to null.

  When bun is not started with the --hot flag

  This string will currently do nothing. But in the future it could be useful for logs or metrics.

• maxRequestBodySize?: number

  What is the maximum size of a request body? (in bytes)

• port?: string | number

  What port should the server listen on?

• websocket: WebSocketHandler<WebSocketDataType>

  Enable websockets with Bun.serve

  For simpler type safety, see Bun.websocket

  Bun.serve({
   websocket: {
     open: (ws) => {
       console.log("Client connected");
     },
     message: (ws, message) => {
       console.log("Client sent message", message);
     },
     close: (ws) => {
       console.log("Client disconnected");
     },
   },
   fetch(req, server) {
     const url = new URL(req.url);
     if (url.pathname === "/chat") {
       const upgraded = server.upgrade(req);
       if (!upgraded) {
         return new Response("Upgrade failed", { status: 400 });
       }
     }
     return new Response("Hello World");
   },
  });
  

  Upgrade a Request to a ServerWebSocket via Server.upgrade

  Pass data in @{link Server.upgrade} to attach data to the ServerWebSocket.data property

• fetch(this: Server, request: Request, server: Server): undefined | void | Response | Promise<undefined | void | Response>

  Handle HTTP requests or upgrade them to a ServerWebSocket

  Respond to Request objects with a Response object.