MERN Authentication System 🔐

A secure and modern full-stack authentication system built using the MERN Stack (MongoDB, Express.js, React.js, Node.js). This project provides robust authentication with JWT, protected routes, and security best practices for real-world production apps.

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🚀 Features

• 🔐 JWT (JSON Web Token) Authentication
• 🔄 User Login & Registration with hashed passwords (bcrypt)
• ✅ Protected Routes for authenticated users only
• 💾 MongoDB with Mongoose for flexible data models
• ⚙️ Express.js API with proper middlewares
• 🌐 React.js Frontend using Context API or Redux
• 📦 Node.js Backend with modular route handling
• 📬 Error Handling with user-friendly messages
• 🧠 Token Storage via HTTP-only cookies or localStorage
• 🔄 Auto Login on page refresh (token-based auth)
• 🚫 Logout Functionality
• 🔐 Secure headers & CORS enabled

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🧱 Tech Stack

Frontend:

• React.js
• Axios
• Tailwind CSS or CSS Modules (if used)
• React Router DOM

Backend:

• Node.js
• Express.js
• MongoDB (with Mongoose)
• JSON Web Token (JWT)
• Bcrypt for password hashing
• dotenv for environment variables
• CORS middleware

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🛠️ Installation & Setup

Step 1: Install Dependencies

Install all packages in both client/ and server/ folders:

step 2 : Add .env file

read the .env.example file and create .env file based on the .env.example file

step 3 : For Client - npm run dev

step 4 : For Server - node server.js