Building a User Authentication and File Management API with FastAPI

#fastapi #python #backend #jwt

Over the past two weeks, I’ve been working on a backend API project using FastAPI. The goal is to build a solid foundation for user authentication and a file management system.

Week 1: User Authentication System

Initialized a FastAPI project with virtualenv and managed dependencies in requirements.txt.
Configured environment variables with python-dotenv for things like SECRET_KEY and DATABASE_URL.
Created the User model using SQLAlchemy with fields including id, email, hashed_password, and status flags.
Implemented JWT-based authentication including user registration, login, and token refresh.
Built user endpoints (/register, /login, /me) for managing user actions.
Added dependency injection for database sessions and authentication in the routes.
Wrote basic tests for authentication endpoints.

At the end of week one, the API supports user registration and login, returning JWT tokens for authorized access.

Week 2: File Management System

Added a File model linked to users, storing file metadata such as filename, hash, and upload date.
Created file endpoints to upload, list, and delete files (/upload, /list, /delete/{file_id}).
Handled file uploads with python-multipart, storing files on disk using unique filenames.
Computed and stored SHA-256 hashes for uploaded files to ensure integrity.
Restricted file access based on user authentication, enforcing ownership rules.
Implemented validation for file size and allowed extensions.
Started writing tests for the file management functionality.

What’s next?

Moving forward, I plan to:

Enhance file validation and error handling.
Add support for user roles and permissions.
Integrate background tasks for file maintenance using Celery.
Improve test coverage and add documentation.

Try it out

The project is open source and available on GitHub: Task Automation API

Feedback and contributions are welcome.

If you’re interested in backend APIs, FastAPI is a great framework that makes building async, secure APIs straightforward. This project is a good way to practice authentication, file handling, and database relationships.

Thanks for reading!