API Test Plan Skill

APIs fail in specific, testable ways: wrong status codes, schema drift, missing auth checks, sloppy validation, unhelpful errors. This skill plans the tests that catch them — per endpoint, across the response codes and the error paths, with contract checks so the API keeps its promises to clients. It tests the whole behaviour, not just the happy 200.

Working from a brief

Given an endpoint or an API description, produce the test plan anyway — infer the likely parameters, responses, auth model, and error cases, labelling assumptions. Always include auth, validation, and negative cases. Never hand back a question instead of a plan.

Required Inputs

Ask for these only if they aren't already provided (else infer and label):