Instant Messaging Application

A real-time instant messaging application I built using Node.js and WebSocket technology. The application provides secure, real-time communication with features like private messaging, user authentication, and persistent data storage.

What It Does

• Enables real-time messaging between users
• Provides secure JWT-based authentication
• Supports private messaging between users
• Maintains user connections and online status
• Stores data persistently in SQLite database

How It Works

The application uses WebSocket for real-time communication and implements a robust event system for different types of messages. It handles user authentication, message routing, and connection management.

// Example of WebSocket server setup
const wss = new WebSocketServer({
  port: SOCKET_SERVER_PORT,
  verifyClient: (info, cb) => {
    // JWT authentication
    const token = extractToken(info.req.headers['authorization']);
    if (verifyJwtToken(token)) {
      cb(true);
    } else {
      cb(false, 401, 'Unauthorized');
    }
  }
});

// Example of message handling
ws.on('message', (message) => {
  const { type, content } = JSON.parse(message);
  switch (type) {
    case 'sendPrivateMessage':
      handleSendPrivateMessage(ws, content);
      break;
    case 'getConnectedUsers':
      handleGetConnectedUsers(ws);
      break;
    // ... other message types
  }
});

Technical Bits

• Built with Node.js and Express
• Uses WebSocket for real-time communication
• Implements JWT for secure authentication
• Stores data in SQLite database
• Handles concurrent connections efficiently
• Manages user sessions and online status

Features

1. Real-time Communication: Instant message delivery using WebSocket
2. Secure Authentication: JWT-based user authentication
3. Private Messaging: Direct communication between users
4. Connection Management: Tracks online users and their status
5. Error Handling: Robust error management and client notifications

Why I Built It

I wanted to create a scalable real-time messaging solution that demonstrates modern web technologies and best practices in real-time communication. This project helped me understand WebSocket implementation, authentication, and real-time data management.

Future Ideas

• Add chat rooms functionality
• Implement message persistence
• Add file sharing capabilities
• Create a web-based client interface
• Add message encryption
• Implement user presence indicators
• Add message read receipts