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Built-in room » Lobby Room

Client-side API for lobby room will change on Colyseus 1.0.0

The built-in lobby room currently relies on sending messages to notify clients about available rooms. When @filter() becomes stable, the LobbyRoom is going to use the state instead.


The built-in LobbyRoom will automatically notify its connected clients whenever rooms with "realtime listing" have updates.

import { LobbyRoom } from "colyseus";

// Expose the "lobby" room.
  .define("lobby", LobbyRoom);

// Expose your game room with realtime listing enabled.
  .define("your_game", YourGameRoom)

The LobbyRoom is notified automatically during onCreate(), onJoin(), onLeave() and onDispose().

If you have updated the metadata of your room, and need to trigger an update for the lobby, you can call updateLobby() right after the metadata has been updated:

import { Room, updateLobby } from "colyseus";

class YourGameRoom extends Room {

  onCreate() {

    // This is just a demonstration
    // on how to call `updateLobby` from your Room
    this.clock.setTimeout(() => {

        customData: "Hello world!"
      }).then(() => updateLobby(this));

    }, 5000);




You need to keep track of the rooms being added, removed and updated through messages sent to the client from the LobbyRoom.

import { Client, RoomAvailable } from "colyseus.js";

const client = new Client("ws://localhost:2567");
const lobby = await client.joinOrCreate("lobby");

let allRooms: RoomAvailable[] = [];

lobby.onMessage("rooms", (rooms) => {
  allRooms = rooms;

lobby.onMessage("+", ([roomId, room]) => {
  const roomIndex = allRooms.findIndex((room) => room.roomId === roomId);
  if (roomIndex !== -1) {
    allRooms[roomIndex] = room;

  } else {

lobby.onMessage("-", (roomId) => {
  allRooms = allRooms.filter((room) => room.roomId !== roomId);

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