This project handles all the backend logic and database interactions for the most of my projects. It is built using FastAPI, PostgreSQL, Docker and Redis.

Docker version of this project Backend-docker. I have deployed it on koyeb which does not support docker deployment for postgresql, so I have to use a separate PostgreSQL service.

🧑‍💻 Technical Details

Built with FastAPI and PostgreSQL.

Used Redis for caching data like OTPs, session management, and other temporary data.

Used SQLAlchemy for DB interactions, with Alembic to manage schema migrations.

Integrated psycopg2-binary as the PostgreSQL driver.

Password hashing using argon2-cffi, and built secure user authentication flows with Authlib, supporting OAuth2 (Google, GitHub).

Pydantic for data validation and serialization throughout the API layers.

Email input validation using email-validator

Utilized Starlette features for middleware and background task management.

Built developer tools and CLI utilities with Typer to streamline database migrations, test user creation, and administrative tasks.

😎 Features

🔐 Auth Features

🔑 User Registration (And Otp Verification)

@router.post("/start-registration"): Start User Registration -> sends an OTP to the user's email -> stores temporary data in Redis(like hashed password, email, username etc.).

@router.post("/verify-otp"): Email OTP Verification -> verifies the OTP sent to the user's email -> if valid, creates a new user in the database -> Deletes temporary data from Redis. @router.post("/resend-otp"): Resend OTP -> generates and sends a new OTP to the user's email.

🔓 User Login

@router.post("/login"): User Login -> verifies user credentials -> generates and returns JWT token.

🔁 Reset Password

@router.post("/request-password-reset"): Request Password Reset -> sends a password reset link to the user's email if the user exists. @router.post("/resend-reset-otp"): Resend Reset OTP -> generates and sends a new OTP to the user's email for password reset. @router.post("/verify-reset-otp"): Verify Reset OTP -> verifies the OTP sent to the user's email for password reset -> if valid, allows the user to reset their password.

🔄 Refresh Token

@router.post("/refresh", response_model=Token): Refresh JWT Token -> verifies the refresh token and issues a new access token.

OAuth2.0

Google and GitHub Login

@router.get("/google"): Google OAuth2 Login -> redirects to Google for authentication. @router.get("/google/callback"): Google OAuth2 Callback -> handles the callback from Google after authentication -> retrieves user information and creates a new user in the database if not exists. @router.get("/github"): GitHub OAuth2 Login -> redirects to GitHub for authentication. @router.get("/github/callback"): GitHub OAuth2 Callback -> handles the callback from GitHub after authentication -> retrieves user information and creates a new user in the database if not exists.

🔑 Session and Account Management

@router.get("/me", response_model=User): Get Current User -> retrieves the current user's profile information. @router.post("/me", response_model=User): Update Current User -> updates the current user's profile information.

📈 Scalability

It's so easy to create new API endpoints for any new feature or service. For any new project, It's just a matter of creating a new FastAPI router and adding it to the main application. Since I have multiple projects, which requires user authentication, This project allows me to reuse the same authentication and user management app across different projects.

📂 Folder Structure

├── app/
│   ├── api/
│   │   └── v1/
│   ├── core/
│   ├── crud/
│   ├── db/
│   │   └── models/
│   ├── schemas/
│   ├── services/
│   └── utils/