🔐 Authentication System API

A simple and secure Authentication API built with Node.js, Express, and MongoDB. It includes all the essentials like user sign-up, login, password reset, and email notifications.

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✅ Features

• User registration & login with JWT
• Access & Refresh token flow
• Password reset via email
• Email verification (HTML templates)
• Input validation using express-validator
• Secure password hashing with bcryptjs
• Environment-based configuration using dotenv

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🛠 Tech Stack

• Backend: Node.js, Express
• Database: MongoDB (Mongoose)
• Email Service: Nodemailer + Mailgen
• Validation: express-validator
• Auth: JWT (Access & Refresh tokens)

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📂 Folder Structure

AuthenticationSystem/

├── src/
│ ├── config/ # DB & SMTP configs
│ ├── controllers/ # Auth logic
│ ├── middlewares/ # Error handler, validation
│ ├── models/ # Mongoose schemas
│ ├── routes/ # API routes
│ ├── utils/ # Helpers (email, tokens)
│ ├── app.js # Express app setup
│ └── server.js # Entry point
├── .env # Environment variables
├── package.json
└── README.md

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⚙️ Installation

1️⃣ Clone the repository

git clone https://github.com/your-username/authentication-system.git
cd authentication-system

2️⃣ Install dependencies

npm install

3️⃣ Setup .env file

PORT=5000
MONGO_URI=your_mongodb_connection_string
JWT_SECRET=your_jwt_secret
ACCESS_TOKEN_EXPIRY=1d
REFRESH_TOKEN_EXPIRY=10d
SMTP_HOST=smtp.yourmail.com
SMTP_PORT=587
SMTP_USER=your_email@example.com
SMTP_PASS=your_email_password

▶️ Run the App

npm start

Starts the server with nodemon for auto-reload.

🔗 API Endpoints

Method	Endpoint	Description
POST	/api/v1/auth/register	Register a new user
POST	/api/v1/auth/login	Login user
POST	/api/v1/auth/logout	Logout user
POST	/api/v1/auth/refresh	Refresh JWT tokens
POST	/api/v1/auth/forgot-password	Send password reset link
POST	/api/v1/auth/reset-password	Reset user password
GET	/api/v1/auth/verify/:id	Verify user email

✉️ Email Templates

Emails are generated using Mailgen for a professional look:

Welcome Email

Password Reset Email

Email Verification

🚀 Future Improvements

Google & GitHub OAuth

Rate limiting for brute-force protection

Two-Factor Authentication (2FA)

✒️ by Shouvik Sarkar