🔐 Authentication System - MERN Stack

A secure and scalable authentication system built with MongoDB, Express.js, React, and Node.js (MERN).
This application provides user registration, login, JWT authentication, and protected routes, serving as a foundation for any full-stack web app.

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🚀 Features

👤 User Authentication

• User Registration & Login with JWT
• Password Hashing using bcrypt
• Email Verification workflow
• Password Reset with secure tokens
• Persistent Sessions with refresh tokens

🔒 Security Features

• Protected Routes with JWT middleware
• Token Expiry & Refresh Mechanism
• CORS-enabled API for secure frontend-backend communication
• Environment Variables for sensitive configuration

📱 UI/UX Features

• Modern UI built with React & TailwindCSS
• Form Validation with helpful error messages
• Responsive Design (Desktop, Tablet, Mobile)
• Toast Notifications for feedback

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🛠️ Tech Stack

Frontend

• React.js - UI Framework
• TailwindCSS - Styling framework
• React Router DOM - Client-side routing
• Axios - API requests

Backend

• Node.js - Runtime environment
• Express.js - Web framework
• MongoDB - Database
• Mongoose - ODM for MongoDB
• JWT - Authentication
• bcrypt.js - Password hashing
• dotenv - Environment configuration
• CORS - Cross-origin resource sharing

🚦 Getting Started

Prerequisites

• Node.js (v16 or higher)
• MongoDB (local or cloud instance, e.g. MongoDB Atlas)
• npm package manager

Installation

1. Clone the repository

   git clone https://github.com/ChandrakantaMandal/Authentication.git
   cd Authentication

2. Install Backend Dependencies

    cd backend
    npm install
   

3. Install Frontend Dependencies

    cd backend
    npm install

4.Setup Environment Variables -In the backend folder, .env.example as the .env file

🏃 Running the Application

1.Start the Backend Server

cd backend
npm run dev

Runs on http://localhost:8080

1.Start the Frontend Development Server*

cd frontend
npm run dev

Runs on http://localhost:5173

🔐 Authentication Flow

1.User registers or logs in → receives a JWT token

2.Token stored in localStorage (frontend)

3.Requests to protected routes include the token in Authorization headers

4.Server verifies token via middleware → grants access

🚀 Deployment

Backend Deployment (Heroku/Railway/Verce

• Set environment variables in deployment platform
• Connect MongoDB Atlas
• Update CORS configuration

• Frontend Deployment (Netlify/Vercel):

• Run npm run build in frontend
• Deploy dist folder to hosting service
• Update API URL in Axios config

Contributing

• Fork the project

• Create a new branch (git checkout -b feature/myFeature)

• Update API URL in Axios config

• Commit your changes (git commit -m "Added new feature")

• Push to branch (git push origin feature/myFeature)

• Open a Pull Request

  📝 License

• This project is licensed under the MIT License – see the LICENSE file for details.

  👨‍💻 Author

  Chandrakanta Mandal

  • GitHub:ChandrakantaMandal