Socket.IO implementation on Roblox

This is a full implementation of Socket.IO on Roblox.

Because Roblox not support WebSocket, this implementation use HTTP long polling to communicate with server.

Limit

Roblox Limit 500 request per minute.

So this implementation will cache send packet and send request every 0.3 seconds.

you can see src/engine.io-client/transports/polling-roblox.ts

RunService.Heartbeat.Connect((dt) => {
	RobloxGlobalConfig.resetTime -= dt;
	if (RobloxGlobalConfig.resetTime < 0) {
		RobloxGlobalConfig.resetTime = RobloxGlobalConfig.REQUEST_TIMES_RESET_INTERVAL;
		RobloxGlobalConfig.requestTimes = 0;
	}
});
task.delay(0, () => {
	while (this.running) {
		this.flush();
		wait(0.3);
	}
});

Roblox request unstable.

So on Server side you need enable connection-state-recovery

import { createServer } from "http";
import { Server } from "socket.io";

const server = createServer();
const io = new Server(server, {
	// enable state recovery
	connectionStateRecovery: {
		// the backup duration of the sessions and the packets
		maxDisconnectionDuration: 2 * 60 * 1000,
		// whether to skip middlewares upon successful recovery
		skipMiddlewares: true,
	},
	pingInterval: 50000,
});
io.on("connection", (socket) => {
	if (socket.recovered) {
		// recovery was successful: socket.id, socket.rooms and socket.data were restored
	} else {
		// new or unrecoverable session
	}
});

const client = io.connect("http://localhost:3000", {
	reconnectionDelay: 10000, // defaults to 1000
	reconnectionDelayMax: 10000, // defaults to 5000
});
socket.on("connect", () => {
	if (socket.recovered) {
		// any event missed during the disconnection period will be received now
	} else {
		// new or unrecoverable session
	}
});

more long interval and send packet one time can reduce request times to prevent triggering roblox request restrictions.

You can config use RobloxGlobalConfig

// default config
export class RobloxGlobalConfig {
	/**
	 * Max request per minute
	 */
	public static MAX_REQUEST_PER_INTERVAL = 200;
	/**
	 * Interval to reset request times
	 */
	public static REQUEST_TIMES_RESET_INTERVAL = 60;
	/**
	 * Interval to flush packets
	 */
	public static FLUSH_PACKET_INTERVAL = 0.3;
}
// Modify config
RobloxGlobalConfig.MAX_REQUEST_PER_INTERVAL = 500;
RobloxGlobalConfig.FLUSH_PACKET_INTERVAL = 0.5;

Installation

npm install @rbxts/socket.io
yarn add @rbxts/socket.io
pnpm add @rbxts/socket.io

Usage

use example

import { io } from "@rbxts/socket.io";

const socket = io("http://localhost:3000");
socket.on("connect", () => {
	print("connected");
});
socket.on("disconnect", () => {
	print("disconnected");
});
socket.on("message", (message) => {
	print(message);
});

namespace support

import { RunService } from "@rbxts/services";
import { io } from "@rbxts/socket.io";

const manager = new Manager("http://localhost:3000");

const socket = manager.socket("/"); // main namespace
const adminSocket = manager.socket("/admin"); // admin namespace

socket.emit("players", { onlines: Players.GetChildren().size() });
adminSocket.on("kick", (uid, reason) => {
	Players.GetPlayerByUserId(uid)?.Kick(reason);
});