NodeJs — WebSockets with Socket.IO

WebSockets enable real-time, bi-directional communication between clients and the server. The 'socket.io' package is a popular library for implementing WebSockets in Node.js applications, ideal for chat apps or live notifications.

npm install socket.io

// server.js
const express = require('express');
const http = require('http');
const { Server } = require('socket.io');

const app = express();
const server = http.createServer(app);
const io = new Server(server);

io.on('connection', socket => {
  console.log('A user connected');
  socket.on('message', msg => {
    io.emit('message', msg);
  });
});

server.listen(3000);