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Can't get basic client/server communication to work

  • Hi!

    I've been trying to get Colyseus up and running but I can't manage to do it. I made it connect a few times but not anymore.

    I'm getting almost always the same error:

    join error MatchMakeError: "game_room" not defined
        at new MatchMakeError (/home/squ3ck/projects/test/client/node_modules/colyseus.js/lib/Client.js:58:28)
        at Client.<anonymous> (/home/squ3ck/projects/test/client/node_modules/colyseus.js/lib/Client.js:182:35)
        at step (/home/squ3ck/projects/test/client/node_modules/colyseus.js/lib/Client.js:45:23)
        at (/home/squ3ck/projects/test/client/node_modules/colyseus.js/lib/Client.js:26:53)
        at fulfilled (/home/squ3ck/projects/test/client/node_modules/colyseus.js/lib/Client.js:17:58)
        at processTicksAndRejections (internal/process/task_queues.js:97:5) {
      code: 4210

    I removed most of my code and left with barebone example code:

    GameRoom.ts is from the example code at:


    import http from "http";
    import express from "express";
    import cors from "cors";
    import { matchMaker, Server } from "colyseus";
    import { monitor } from "@colyseus/monitor";
    import { GameRoom } from "./GameRoom";
    const port = Number(process.env.PORT || 2567);
    const app = express()
    const gameServer = new Server({
      server: http.createServer(app),
      express: app,
      pingInterval: 0,
    // register your room handlers
    // gameServer.define("my_room", MyRoom);
    gameServer.define("game_room", GameRoom);
    app.use("/colyseus", monitor());
    console.log(`Listening on ws://localhost:${ port }`)


    var colyseus = require('colyseus.js')
    let client = new colyseus.Client("ws://localhost:2567");
    client.joinOrCreate("game_room", {}).then(room => {
      console.log("joined successfully", room);
    }).catch(e => {
      console.error("join error", e);

    Creating the room from the server works, but still can't join from the client.

    matchMaker.createRoom("game_room", {}).then(room => console.log(room));

    prints this:

    RoomCache {
      clients: 0,
      locked: false,
      private: false,
      maxClients: Infinity,
      createdAt: 2020-03-28T00:05:33.941Z,
      name: 'game_room',
      processId: 'hmecnUvQa',
      '$rooms': [ [Circular] ],
      roomId: 's2BR8Qfx3'

    I have installed the server with npm init colyseus-app and the client with npm install --save colyseus.js

    It has also happened that the client your report a successful room join but no join events would fire on the server.

    What am I missing? Thanks!

  • hi,you should use matchMaker.defineRoomType to defind this room.

  • Thanks for your reply!

    I think this was a networking issue in the end (maybe due to WSL on Windows) -- I changed the server port and now everything's working even without


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