⚙️ Quick Chat App — Backend Server

This is the backend service for the Quick Chat App, built with Node.js, Express.js, MongoDB, and Socket.IO. It provides REST APIs and real-time communication for messaging, authentication, and user management.

🚀 Features

• 🔐 JWT-based Authentication (Signup/Login)
• 👤 User management & profile handling
• 💬 One-to-one real-time chat with Socket.IO
• 📨 Message storage & retrieval
• ☁️ Image upload support via Cloudinary
• 🛡️ Protected routes with middleware
• ⚡ Scalable and modular structure

🛠️ Tech Stack

• Node.js
• Express.js
• MongoDB + Mongoose
• Socket.IO
• Cloudinary (for media uploads)
• JSON Web Token (JWT)

📁 Folder Structure

Server/
├─ config/
│  └─ dbConfig.js          # MongoDB connection setup
│
├─ controllers/            # Request handling logic
│  ├─ authController.js
│  ├─ chatController.js
│  ├─ messageController.js
│  └─ userController.js
│
├─ middlewares/            # Custom middleware
│  └─ authMiddleware.js    # JWT verification
│
├─ models/                 # Mongoose schemas
│  ├─ chat.js
│  ├─ message.js
│  └─ user.js
│
├─ app.js                  # Express app configuration
├─ server.js               # Server entry point (HTTP + Socket.IO)
├─ cloudinary.js           # Cloudinary configuration
│
├─ .env                    # Environment variables
├─ .env.example            # Sample environment file
├─ .gitignore
├─ package.json
├─ package-lock.json
└─ README.MD

⚙️ Environment Variables

Create a .env file in the root directory:

PORT=create a port
MONGO_URI=your_mongodb_connection_string
JWT_SECRET=your_jwt_secret

# Cloudinary Config
CLOUDINARY_CLOUD_NAME=your_cloud_name
CLOUDINARY_API_KEY=your_api_key
CLOUDINARY_API_SECRET=your_api_secret

⚙️ Installation & Setup

Clone Repository

git clone https://github.com/Nayan-Krishna-Ball/Chat-application-server.git

Install dependencies

npm install

▶️ Run the Server

Development mode

npm run dev

Production mode

npm start

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🔌 API Overview

🔐 Authentication

Method	Endpoint	Description
POST	/api/auth/signup	Register new user
POST	/api/auth/login	Login user

---

👤 Users

Method	Endpoint	Description
GET	/api/users	Get all users
GET	/api/users/:id	Get user by ID
PUT	/api/users/:id	Update user profile

---

💬 Chats

Method	Endpoint	Description
POST	/api/chat	Create or access chat
GET	/api/chat	Get user chats

---

📨 Messages

Method	Endpoint	Description
POST	/api/messages	Send a message
GET	/api/messages/:chatId	Get chat messages

---

🔄 Real-Time Communication (Socket.IO)

📡 Connection Events

• connection → User connects
• disconnect → User disconnects

---

💬 Chat Events

• join_chat → Join a chat room
• send_message → Emit message
• receive_message → Receive message

☁️ File Uploads

• Uses Cloudinary for storing images
• Configured in cloudinary.js
• Can be used for:
  • Profile pictures
  • Chat media (images)

---

🔐 Authentication & Security

• JWT stored on client side
• Protected routes via authMiddleware
• Token required in headers:

Authorization: Bearer <token>

🧠 Application Flow

1. User authenticates → receives JWT
2. Client connects to Socket.IO server
3. User joins chat rooms
4. Messages are:
   • Saved in database
   • Emitted in real-time

📌 Future Improvements

• ✅ Group chat support
• ✅ Message reactions
• ✅ Online/offline status
• ✅ Push notifications
• ✅ End-to-end encryption

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🧪 Testing

Recommended tools:

• Postman
• Thunder Client

🤝 Contributing

1. Fork the repository
2. Create a new branch (feature/your-feature)
3. Commit your changes
4. Push and create a Pull Request