FastAPI Login System 🔐

A production-style authentication and authorization backend built using FastAPI, featuring secure user authentication, JWT-based access control, and database-backed user management.

This project demonstrates how modern backend systems handle authentication, security, and role-based access using industry-standard practices.

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🚀 Features

• User registration and login
• Secure password hashing
• JWT-based authentication (access tokens)
• Role-based access control (RBAC)
• Protected routes using dependency injection
• PostgreSQL database integration
• SQLAlchemy ORM for data modeling
• Environment-based configuration
• Automatic API documentation (Swagger / OpenAPI)

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🧠 Tech Stack

• Backend Framework: FastAPI
• Language: Python
• Database: PostgreSQL
• ORM: SQLAlchemy
• Auth: JWT (JSON Web Tokens)
• Security: Password hashing with passlib
• API Docs: Swagger UI (built-in FastAPI)

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📁 Project Structure

login-fastapi/
├── app/
│   ├── main.py
│   ├── database.py
│   ├── models.py
│   ├── schemas.py
│   ├── auth.py
│   ├── dependencies.py
│   └── routes/
│       ├── auth.py
│       └── users.py
├── .env
├── requirements.txt
└── README.md

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🔐 Authentication Flow

1. User registers with email and password
2. Password is securely hashed before storage
3. User logs in with valid credentials
4. Server issues a signed JWT access token
5. Client sends token in Authorization header
6. Protected routes validate token and user role

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🛠️ Setup & Installation

Clone the repository

git clone https://github.com/404zhan/login-fastapi.git
cd login-fastapi

Create virtual environment

python -m venv venv
source venv/bin/activate

Install dependencies

pip install -r requirements.txt

Environment variables

DATABASE_URL=postgresql://username:password@localhost:5432/dbname
SECRET_KEY=your_secret_key
ALGORITHM=HS256
ACCESS_TOKEN_EXPIRE_MINUTES=30

Run the server

uvicorn app.main:app --reload

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📖 API Documentation

• Swagger UI: http://127.0.0.1:8000/docs
• ReDoc: http://127.0.0.1:8000/redoc

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👤 Author

Azhan Farooqui
GitHub: https://github.com/404zhan