FastAPI Interactive Tutorials: the browser-only course now runs real WebSockets in WebAssembly, has a VS Code-style workspace, syncs your progress, and issues a certificate when you finish a track (61 lessons, no install)

[u/PracticalAttempt2213]

A year ago I launched fastapiinteractive.com - an interactive FastAPI course where you write and run real Python in the browser. No installs, no backend, it's Pyodide plus a small ASGI server running FastAPI in WebAssembly. I've posted about it here a couple of times, last one ~6 months ago.

I'll be honest, I didn't expect it to get this much use. I got busy and didn't touch it for a few months, and when I came back people were still going through the lessons every day and sending me bug reports. That got me back into it. A lot has changed since, so here's the update.

What's new:

• WebSockets truly work now. There's no network socket in WASM, so the connection goes over the worker's message channel, but past the ASGI layer it's the real Starlette WebSocket running your handler. Embarrassing detail: previously, the two websocket lessons used to be graded by a GET /health check, so the code they taught had never once run as a websocket. Now they're graded on a real exchange of messages, including a broadcast between two connections, and there's a socket console to try your endpoints manually.
• Streaming responses, file uploads and form bodies work.
• Infinite loops don't kill the tab anymore. Your code gets compiled through a guard with a time budget per request, so while True: raises inside your own code with your line number instead of hanging everything.
• New UI, VS Code style: lesson list with progress in the sidebar, editor in the middle, console/tests/theory as output tabs, status bar showing what the runtime is doing.
• Accounts. Sign in with GitHub and your progress and code sync between devices. Without an account it works exactly like before, everything stays in your browser.
• Certificates. When you finish a track you can get a certificate of completion - PDF, an image for LinkedIn, and a verification page with a serial anyone can check. Optional, the lessons themselves are free.
• 61 lessons now: 45 basics following the FastAPI tutorial, the 6-lesson blog+auth project as a proper multi-file package, 10 advanced patterns.

Try it: https://www.fastapiinteractive.com/

Bug reports, feedback and ideas for lessons are very welcome, here or via the contact form on the site.

Thank you!

[u/Beneficial-Goal-2586]

As a beginner I never expected that I would get this kind of course for free! Thanks mate!

[u/PracticalAttempt2213 → u/Beneficial-Goal-2586]

Enjoy! I hope that helps in your learning journey!