api-testing

API Testing

Overview

Three tools, matched to what already exists:

Don't reach for the heavier tool when the lighter one already answers the question — a one-off endpoint check doesn't need a collection, and a collection run doesn't need Playwright.

postman request — over curl, not instead of testing

A single request with Postman's resolution built in: -e resolves {{variables}} from an environment file the same way a collection run would, --auth-* flags cover basic/bearer/digest/oauth/aws/etc. without hand-building headers, and --retry/--timeout handle flaky endpoints. --script-post-request can run pm.test(...) assertions inline — the exit code counts failed assertions, not just HTTP status, so a 200 with a failing test still exits nonzero. Useful for a quick check or a CI health check; not the place to accumulate assertions that should outlive one command — those belong saved in a collection.

collection run — the assertion suite

Debugging a request's behavior during a run (why a pm.test failed, what a request actually sends) means reading the request's own YAML — see the collection-schema-v3 skill for that file format before assuming a field's shape.

Runs every request in a collection (or a subset via -i, repeatable), executing whatever pm.test scripts are already saved in it. -d/--iteration-data (or the beta --iteration-data-dataset + --iteration-data-view pair) drives data-driven runs across a CSV/JSON file or a Postman Dataset. -r junit,html for CI-consumable reports. --use-mock/--mock redirects the run at a mock instead of a real backend (see the api-mocking skill) — reach for this to test request/assertion logic without depending on a live service.