Getting started

A 5-minute guide to testing HTTP status codes, Bearer auth, pagination, idempotency and optimistic concurrency with Fun API Playground’s mock REST APIs.

1. Pick an API and open its docs
2. Send your first request with Try it out
3. Authorize for protected endpoints (qa-admin-token / qa-viewer-token)
4. Practice negative testing — 400, 401, 403, 404, 418, 500, 503 on demand
5. Export the OpenAPI spec or Postman collection into your own tools
6. Test concurrency (ETag / If-Match) and idempotency (Idempotency-Key)
7. Automate it — deterministic mode, contract testing, timeouts

Go deeper on one technique: Pagination testing · Rate limit testing · Idempotency key testing · ETag and If-Match testing · Webhook signature testing · OAuth and JWT testing · Negative testing · Async job testing

Or look up a status code: all 28 of them

Browse all 39 APIs