🔐 Gagan Auth Kit

A lightweight, reusable authentication module for Express.js applications with JWT-based authentication, password hashing with bcryptjs, and MongoDB support.

✨ Features

• User Registration & Login - Pre-built routes for user authentication
• JWT Token Management - Secure token generation and validation
• Password Hashing - Bcryptjs integration for secure password storage
• Route Protection Middleware - Protect routes with protectRoute middleware
• Mongoose Integration - Works seamlessly with MongoDB via Mongoose
• Easy Integration - Simple initialization with minimal configuration

📦 Installation

npm install gagan-auth-kit

🚀 Quick Start

1. Initialize the Auth Module

const express = require('express');
const InitializeAuth = require('gagan-auth-kit');
const mongoose = require('mongoose');
const { userSchema } = require('./models/User'); // Your User model

const app = express();
app.use(express.json());

// Define your User model
const User = mongoose.model('User', userSchema);

// Initialize the auth kit
const { authRouter, protectRoute } = InitializeAuth({
  UserModel: User,
  jwtSecret: process.env.JWT_SECRET || 'your-secret-key'
});

// Use the auth router
app.use('/auth', authRouter);

// Example: Protect a route
app.get('/profile', protectRoute, (req, res) => {
  res.json({ message: 'This is a protected route', user: req.user });
});

app.listen(3000, () => console.log('Server running on port 3000'));

2. User Model Example

const mongoose = require('mongoose');

const userSchema = new mongoose.Schema({
  name: {
    type: String,
    required: true
  },
  email: {
    type: String,
    required: true,
    unique: true
  },
  password: {
    type: String,
    required: true
  },
  createdAt: {
    type: Date,
    default: Date.now
  }
});

module.exports = mongoose.model('User', userSchema);

📚 API Reference

InitializeAuth(options)

Initializes the authentication module with your configuration.

Parameters:

• options.UserModel (required): Your Mongoose User model
• options.jwtSecret (required): Secret key for JWT signing

Returns:

{
  authRouter: Express.Router,    // Router with /register and /login routes
  protectRoute: Function         // Middleware to protect routes
}

Routes

POST /register

Create a new user account.

Request Body:

{
  "name": "John Doe",
  "email": "[email protected]",
  "password": "securepassword123"
}

Response:

{
  "message": "User registered successfully",
  "user": {
    "_id": "...",
    "name": "John Doe",
    "email": "[email protected]"
  }
}

POST /login

Authenticate user and receive JWT token.

Request Body:

{
  "email": "[email protected]",
  "password": "securepassword123"
}

Response:

{
  "message": "Login successful",
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  "user": {
    "_id": "...",
    "name": "John Doe",
    "email": "[email protected]"
  }
}

Middleware: protectRoute

Protects routes by requiring a valid JWT token in the Authorization header.

Usage:

app.get('/protected-endpoint', protectRoute, (req, res) => {
  console.log(req.user); // Decoded JWT payload
  res.json({ message: 'Access granted', user: req.user });
});

Authorization Header Format:

Authorization: Bearer <your_jwt_token>

🔧 Environment Variables

Create a .env file in your project:

JWT_SECRET=your_very_secret_key_here
MONGODB_URI=mongodb://localhost:27017/your-db
NODE_ENV=development

📋 Dependencies

• express - Web framework
• mongoose - MongoDB object modeling
• jsonwebtoken - JWT token generation and validation
• bcryptjs - Password hashing
• dotenv - Environment variable management

🤝 Error Handling

The module returns standard HTTP status codes:

• 200 - Success
• 201 - User created
• 400 - Invalid input or user already exists
• 401 - Unauthorized (invalid credentials or token)
• 500 - Server error

🔐 Security Best Practices

1. Never hardcode secrets - Always use environment variables
2. Use HTTPS in production - Ensure secure token transmission
3. Implement rate limiting - Prevent brute force attacks
4. Set appropriate JWT expiration - Balance security and user experience
5. Store tokens securely - Use httpOnly cookies on the client-side

📝 License

ISC

👨‍💻 Author

Gagan

🤝 Contributing

Feel free to fork and submit pull requests for any improvements.

📞 Support

For issues and questions, please open an issue on GitHub.