AI agents write backend code fast. A new endpoint, a validation rule, a background

job - a few minutes and it's done. The part that usually stays behind is the proof

that the API really behaves the way you think it does.

Unit tests help, and agents are happy to write them. However, they test classes,

not the HTTP contract: status codes, headers, JSON shapes, auth, and what happens

when a background job finishes two seconds later. That's what integration tests are

for, and that's exactly the part I want the agent to do for me.

In this post I'll show how I let an agent write, run and fix API integration tests

with TeaPie - and why plain .http files turned out to be

a great format for it.

💁 If you haven't used TeaPie yet, the

getting started post takes five minutes.

You don't need it to follow this one, though.

Why TeaPie fits AI agents

An agent works in a loop: write something, run it, read the output, fix it, repeat.

The faster and clearer that loop is, the better the result.…