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Ship Multiplayer
Games
Faster

Build and ship real-time multiplayer experiences with Colyseus. Open-source framework for Node.js with built-in matchmaking, state sync, and SDKs for Unity, Defold, Construct, Haxe, JavaScript, and more.

$ npm create colyseus-app@latest ./my-server

Requires Node.js

Trusted by teams with millions of players

See It In Action

Real-Time State Sync in Minutes

Define your game state on the server. Colyseus syncs it to all clients automatically — no manual serialization needed.

GameRoom.ts Server
import { Room, Client } from "colyseus";
import { GameState, Player } from "./GameState";
export class GameRoom extends Room {
state = new GameState();
messages = {
// listen for "move" messages from clients
move(client: Client, data: any) {
const player = this.state.players.get(client.sessionId);
if (player) {
player.x = data.x;
player.y = data.y;
}
},
}
onJoin(client: Client) {
const player = new Player();
this.state.players.set(client.sessionId, player);
}
onLeave(client: Client) {
this.state.players.delete(client.sessionId);
}
}
client.ts Client
import { Client, Callbacks } from "@colyseus/sdk";
const client = new Client("https://your-server.com");
const room = await client.joinOrCreate("game_room");
const callbacks = Callbacks.get(room);
callbacks.onAdd("players", (player, key) => {
addSpriteForPlayer(player);
callbacks.onChange(player, () =>
moveSprite(key, player.x, player.y));
});
callbacks.onRemove("players", (player, key) =>
removeSpriteForPlayer(key));
room.send("move", { x: 10, y: 20 });
npm install @colyseus/sdk
Game.tsx Client
import { Client } from "@colyseus/sdk";
import { useRoom, useRoomState } from "@colyseus/react";
const client = new Client("https://your-server.com");
function Game() {
const { room, isConnecting } = useRoom(
() => client.joinOrCreate("game_room"),
);
const state = useRoomState(room);
if (isConnecting) return <p>Connecting...</p>;
return (
<ul>
{state?.players.map((player, key) => (
<li key={key}>Player at {player.x}, {player.y}</li>
))}
</ul>
);
}
npm install @colyseus/react
GameClient.cs Client
using Colyseus;
using Colyseus.Schema;
var client = new Client("https://your-server.com");
var room = await client.JoinOrCreate<GameState>("game_room");
var callbacks = Callbacks.Get(room);
callbacks.OnAdd(state => state.players, (sessionId, player) => {
AddSpriteForPlayer(player);
callbacks.OnChange(player, () =>
MoveSprite(sessionId, player.x, player.y));
});
callbacks.OnRemove(state => state.players, (sessionId, player) =>
RemoveSpriteForPlayer(sessionId));
await room.Send("move", new { x = 10, y = 20 });
client.gd Client
var client: ColyseusClient = Colyseus.create_client()
client.set_endpoint("wss://your-server.com")
var room: ColyseusRoom = client.join_or_create("game_room")
room.joined.connect(func():
var callbacks = Colyseus.callbacks(room)
callbacks.on_add("players", func(player, key):
add_sprite_for_player(player)
callbacks.on_change(player, func():
move_sprite(key, player.x, player.y)
)
)
callbacks.on_remove("players", func(player, key):
remove_sprite_for_player(key)
)
room.send("move", {"x": 10, "y": 20})
)
obj_client.gml Client
client = new ColyseusClient("https://your-server.com");
room = client.join_or_create("game_room");
callbacks = ColyseusCallbacks(room);
callbacks.on_add("players", function(player, key) {
add_sprite_for_player(player);
callbacks.on_change(player, function() {
move_sprite(key, player.x, player.y);
});
});
callbacks.on_remove("players", function(player, key) {
remove_sprite_for_player(key);
});
room.send("move", { x: 10, y: 20 });
client.lua Client
local ColyseusSDK = require "colyseus.sdk"
local client = ColyseusSDK.Client("https://your-server.com")
client:join_or_create("game_room", function(room)
local callbacks = ColyseusSDK.callbacks(room)
callbacks:on_add("players", function(player, key)
add_sprite_for_player(player)
callbacks:on_change(player, function()
move_sprite(key, player.x, player.y)
end)
end)
callbacks:on_remove("players", function(player, key)
remove_sprite_for_player(key)
end)
room:send("move", { x = 10, y = 20 })
end)
Client.hx Client
import io.colyseus.Client;
import io.colyseus.schema.Callbacks;
var client = new Client("https://your-server.com");
client.joinOrCreate("game_room", [], MyRoomState, function(err, room) {
var callbacks = Callbacks.get(room);
callbacks.onAdd("players", (player, key) -> {
addSpriteForPlayer(player);
callbacks.onChange(player, () ->
moveSprite(key, player.x, player.y));
});
callbacks.onRemove("players", (player, key) ->
removeSpriteForPlayer(key));
room.send("move", {x: 10, y: 20});
});
haxelib install colyseus
client.c Client
#include "colyseus.h"
colyseus_client_t* client = colyseus_client_new("https://your-server.com");
colyseus_room_t* room = colyseus_join_or_create(client, "game_room");
colyseus_callbacks_t* callbacks = colyseus_callbacks_get(room);
void on_player_add(colyseus_state_t* player, const char* key) {
add_sprite_for_player(player);
colyseus_on_change(callbacks, player, on_player_change, (void*)key);
}
void on_player_change(colyseus_state_t* player, void* ctx) {
float x = colyseus_get_float(player, "x");
float y = colyseus_get_float(player, "y");
move_sprite((const char*)ctx, x, y);
}
colyseus_on_add(callbacks, "players", on_player_add, NULL);
colyseus_on_remove(callbacks, "players", on_player_remove, NULL);
colyseus_room_send(room, "move", data, data_len);
game.js Client
const client = new Colyseus.Client("https://your-server.com");
const room = await client.joinOrCreate("game_room");
const callbacks = Colyseus.Callbacks.get(room);
callbacks.onAdd("players", (player, key) => {
const sprite = runtime.objects.Player.createInstance("Game", player.x, player.y);
callbacks.onChange(player, () => {
sprite.x = player.x;
sprite.y = player.y;
});
});
callbacks.onRemove("players", (player, key) => {
// destroy sprite instance
});
room.send("move", { x: 10, y: 20 });

Showcase

Games Using Colyseus

A selection of multiplayer games made by happy developers.

Watch the Colyseus Reel

No Vendor Lock-In

Your Server, Your Rules

Colyseus is a standard Node.js application. Deploy it anywhere — no proprietary runtimes, no walled gardens, no surprises.

Standard Node.js

No proprietary runtime. Your Colyseus server is just a Node.js app — use any npm package, any tooling you already know.

Host Anywhere

AWS, Google Cloud, DigitalOcean, Fly.io, Railway, bare metal — if it runs Node.js, it runs Colyseus.

Don't want to manage servers?

Colyseus Cloud handles deployment, scaling, and monitoring across 32 global locations. Starting at $15/mo.

Compare

How Colyseus Compares

vs Photon

  • Open-source, own your servers
  • No CCU pricing surprises
  • Full server-side control

vs Mirror

  • Works with any game engine
  • Not tied to Unity
  • Runs as a standalone server process

vs Nakama

  • Simpler API, faster to learn
  • TypeScript-native
  • Purpose-built for room-based multiplayer

vs From Scratch

  • Battle-tested in production
  • Ship in days, not months
  • Active community support

Community

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