API integration checks

Tests service boundaries with invalid input, overlapping requests and partial outages to reveal inconsistent or duplicated outcomes.

api-integration-qa

Team members using this skill

AgentRami

See how it helps

When is it useful?

Use when several services exchange requests and failures could leave work pending or duplicated.

What does it help you do?

Tests malformed payloads and invalid query parameters directly against the API.
Checks repeated requests and outdated versions for duplicate effects or lost updates.
Exercises stable pagination, upstream timeouts and interrupted streams across service boundaries.

Try asking this

Test an order API with duplicate submissions, simultaneous edits and a payment-provider timeout. Check persisted order and payment records after each attempt. A retry must not duplicate a charge, and a stale edit must not overwrite a newer one.

Detailed documentation

Read the skill’s original instructions, examples and checks in their authored language.

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API & Integration QA

Use this skill when testing backend endpoints, client-server contracts, webhooks, and external service integrations to ensure invalid inputs, retries, and partial failures are handled safely.

Workflow

Verify request validation and contract enforcement:
- Do not test only through the frontend UI, which may block invalid inputs client-side. Test API contracts directly with:
  - Missing required fields, unexpected extra fields, wrong data types ("123" vs 123, null, {}), and oversized payloads.
  - Invalid Content-Type headers, malformed JSON, and out-of-range query parameters (limit=-1, limit=999999, invalid cursor/UUID).
- Confirm that the API returns structured, documented 4xx domain errors (400, 401, 403, 404, 409, 422) without leaking stack traces, SQL queries, or internal paths.
Test idempotency, retries, and concurrency:
- Replay POST / PATCH / DELETE requests with the same Idempotency-Key or duplicate webhook delivery ID and verify the operation executes once without duplicating records or side effects.
- Test optimistic concurrency (expectedVersion / ETag) so stale updates fail cleanly with 409 Conflict rather than silently overwriting newer changes.
Test pagination, filtering, and sorting:
- Verify stable ordering when items share identical timestamps.
- Check boundary pages (empty result [], page 1, last page, and when an item is inserted or deleted between page fetches).
Test upstream timeouts and partial failures:
- Verify how the system behaves when an external API, LLM provider, or queue worker returns 429 Too Many Requests, 502/503/504, or disconnects mid-stream:
  - Does the system surface a clear status and allow safe retry/recovery without leaving stuck 'running' or 'pending' state?

Included files 1

SKILL.md