Real-Time Chat Backend API

A Node.js-based backend for a real-time chat application, built using Express, MongoDB, and Socket.io. This API enables user registration/login, secure messaging, and real-time communication with persistent storage.

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🚀 Features

• 🔐 User Authentication with JWT and hashed passwords using bcrypt
• 📩 Real-Time Messaging using Socket.io
• 🧾 Persistent Chat History with MongoDB
• 📡 REST APIs for users and messages
• 🌐 CORS-enabled for frontend integration
• 🧪 Structured error handling and scalable design

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🛠️ Tech Stack

• Backend: Node.js, Express
• Database: MongoDB (via Mongoose)
• Authentication: JWT, bcrypt
• WebSocket: Socket.io
• Environment Variables: dotenv
• Frontend Compatibility: CORS enabled for http://localhost:3000

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📁 Folder Structure

├── models/
│   ├── User.js
│   └── Messages.js
├── routes/
│   └── auth.js
├── .env
├── server.js
├── package.json

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🔧 Environment Variables

Create a .env file in the root:

PORT=5001
MONGO_URI=your_mongodb_connection_string
JWT_SECRET=your_jwt_secret

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📦 Installation & Run

1. Clone the repository

   git clone https://github.com/your-username/chat-backend.git
   cd chat-backend

2. Install dependencies

   npm install

3. Start the server

   npm start

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🧪 API Endpoints

Auth

• POST /auth/register – Register user
• POST /auth/login – Login user

Users

• GET /users?currentUser=username – Fetch all users except current

Messages

• GET /messages?sender=A&receiver=B – Fetch conversation between two users
• Socket: send_message – Send real-time message
• Socket: receive_message – Receive messages

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📬 Socket.io Events

• connection – Connect new user
• send_message – Emit message to receiver
• receive_message – Broadcast new message
• disconnect – Handle disconnection

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🧑‍💻 Author

• Mayank Jaiswal