Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add petrkindlmann/qa-skills --skill api-testinggit clone --depth 1 https://github.com/petrkindlmann/qa-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/petrkindlmann/qa-skills/api-testing)<a href="https://agentmods.dev/skills/petrkindlmann/qa-skills/api-testing"><img src="https://agentmods.dev/badge/skills/petrkindlmann/qa-skills/api-testing/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/petrkindlmann/qa-skills/api-testing"><img src="https://agentmods.dev/badge/skills/petrkindlmann/qa-skills/api-testing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00129 | $0.02787 |
| Opus 5.5 | $0.00052 | $0.01115 |
| Sonnet 5.5 | $0.00026 | $0.00557 |
| Haiku 4.5 | $0.00013 | $0.00279 |
Grade A, and why
api-testing scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
| **Hurl** (8.x) | Plain-text HTTP testing, CI smoke checks | One file = many requests + assertions; runs anywhere curl runs; certificate + JSONPath (RFC 9535) queries | How it starts
The opening of the file, as written. The whole thing — 192 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Discovery Questions
Check .agents/qa-project-context.md first — if it exists, use it and skip anything already answered there. Then:
- REST, GraphQL, or both? REST-only suites use standard HTTP assertions. GraphQL needs query/mutation builders and benefits from an introspection-diff snapshot.
- Auth mechanism? JWT, API key, OAuth 2.0, or session cookies — each needs a different fixture strategy.
- OpenAPI/Swagger spec available? If yes, auto-generate Zod schemas as contracts (
orval,openapi-zod-client) and consider spec-driven fuzzing with Schemathesis.
Core Principles
- Test contracts, not implementations. Assert on response shape, status codes, and headers — not on internal logic or database state.
- Schema validation catches drift before it breaks consumers. A failing schema test means you caught a breaking change before your frontend did.
- Auth flows are tests too. Test the application's login, logout, expiry and permission contracts. Exercise refresh only when supported. A cleared client cookie does not prove the server revoked the session.
- Response time is a testable assertion. Performance regressions caught in CI are cheaper than production incidents.
Exploratory vs Automated: Tooling
API exploration (debugging, manual probing, OpenAPI playground) and automated API testing are different jobs. Use the right tool for each:
| Tool | Best for | Why |
|---|---|---|
| Bruno (v3.4+) | File-based collections, git-reviewable workflows, FOSS Postman replacement | Filesystem-first, no cloud sync required; gRPC + OAuth + GraphQL query builder |
| Hurl (8.x) | Plain-text HTTP testing, CI smoke checks | One file = many requests + assertions; runs anywhere curl runs; certificate + JSONPath (RFC 9535) queries |
| Hoppscotch | Web-based Postman-style exploration | Open source, runs in browser, good for quick checks |
Playwright APIRequestContext |
Automated tests in your test runner | This skill's focus — covered below |
| Supertest (Node) / httpx (Python) | In-process API tests against your own app | Fastest feedback when you control both sides |
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday Changed · +26 lines 47503141ae9d
- 1mo ago First seen · 166 lines · 129 tokens per session scan A 075520dac51d
api-testing is a skill published in the GitHub repository petrkindlmann/qa-skills (199 stars, last pushed today), licensed MIT. It adds 129 tokens to every session and 2,787 once invoked, about $0.0005 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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