Test your API wrapper without spending real tokens

I don't want to burn API credit every time I run my test suite, but I still need it to catch real bugs.

Intermediate to advancedRead 5 minDoing: about an hour, most of it spent copying your wrapper's real reply shape into one fake object and scripting a couple of failure sequences7 steps

▶ Start

What you'll have at the end

A test suite that runs against a mocked API response and still verifies your error handling and retry logic.

Before you start

You need

A wrapper function or class that already sends a real request to an LLM API, parses the reply into plain text, and includes whatever retry or error-handling logic you want your tests to prove actually works.

Not covered

This doesn't set up an occasional live check against the real API to catch the day its reply shape changes; that's a separate, rarely run habit layered on top of a mocked suite.

Leans on

7 steps

Where to go next

Retry a rate-limited API call with backoff instead of a crash

when you don't have a retrying wrapper yet to test; build it first, then come back here to prove it works without spending real tokens

Checked 15 Aug 2026

Part of the LLM APIs and Integration cookbook