Module 01 Summary

What this module established

Build an API when something outside your process must call you - within one process an import is faster, typed, and cannot fail over the network. The contract is request, response, errors and guarantees: everything behind it is replaceable, and nothing in it can be silently withdrawn.

Carry forward

• FastAPI gives async I/O and fast validation, and more usefully one declaration serving as validation, serialisation and documentation. It does not make your handler faster.
• Use async def when you await something. A blocking call inside async def stalls every other request on that worker.
• Add capability one stage at a time. State and queues add the most operational weight, and the commonest over-build is a database in week one.

Before moving on

Move on when you have a written contract including every error status, and a test named for each guarantee.

Mark complete