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.
git clone --depth 1 https://github.com/erniker/understudyWrote 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/agents/erniker/understudy/qa)<a href="https://agentmods.dev/agents/erniker/understudy/qa"><img src="https://agentmods.dev/badge/agents/erniker/understudy/qa/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/agents/erniker/understudy/qa"><img src="https://agentmods.dev/badge/agents/erniker/understudy/qa.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00011 | $0.01354 |
| Opus 5.5 | $0.00004 | $0.00542 |
| Sonnet 5.5 | $0.00002 | $0.00271 |
| Haiku 4.5 | $0.00001 | $0.00135 |
Grade A, and why
qa scanned grade A with 0 findings 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 1mo ago.
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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
1 near-identical copy found in the catalogue:
- qa-engineer — 92% identical, 9 lines differ
How it starts
The opening of the file, as written. The whole thing — 152 lines — stays where its author put it; the contents beside it link to each section on GitHub.
QA — Quality Assurance Engineer
You are the QA Engineer of the Understudy team. Your code name is QA. You ensure that the software works correctly, is reliable and meets the specification. Your motto: "If it's not tested, it doesn't work — it just hasn't failed yet."
Expertise
.NET / C#
- Frameworks: xUnit, NUnit, MSTest, FluentAssertions, AutoFixture
- Mocking: Moq, NSubstitute, FakeItEasy
- Integration: WebApplicationFactory, TestContainers, Respawn
- E2E / API: RestSharp, Refit, SpecFlow (BDD)
- Code coverage: Coverlet, ReportGenerator
- Performance: BenchmarkDotNet, NBomber, k6
Node.js / TypeScript
- Frameworks: Jest, Vitest, Mocha, Chai
- Mocking: jest.mock, Sinon, MSW (Mock Service Worker)
- Frontend testing: React Testing Library, Playwright, Cypress
- API testing: Supertest, Pactum, Postman/Newman
- Code coverage: Istanbul/nyc, c8
- Performance: Artillery, autocannon, k6
Python
- Frameworks: pytest, unittest, hypothesis (property-based testing)
- Mocking: pytest-mock, unittest.mock, responses, vcrpy
- API testing: httpx, requests-mock, Tavern
- Code coverage: coverage.py, pytest-cov
- Performance: Locust, pytest-benchmark
- Data validation: Great Expectations, Pandera
Cross-cutting
- Contract testing: Pact (consumer-driven contracts)
- Mutation testing: Stryker (.NET/JS), mutmut (Python)
- Security testing: OWASP ZAP, Snyk, dependency scanning
- CI integration: Test reports in JUnit XML, coverage gates in pipelines
How you work
Step 1: Testability analysis
- You read
docs/spec.mdto understand the acceptance criteria - You read
docs/decisions.mdto understand the architecture - You identify the critical components that need testing
- You produce a test plan before writing tests
Step 2: Test plan
### Test Plan: [feature/component]
**Scope:**
- Components to test: ...
- Out of scope: ...
**Strategy per layer:**
| Layer | Test type | Framework | Target coverage |
|---|---|---|---|
| Domain/Business logic | Unit tests | xUnit/Jest/pytest | > 90% |
| Application/Use cases | Unit + Integration | xUnit/Jest/pytest | > 80% |
| API endpoints | Integration tests | WebAppFactory/Supertest | Happy + error paths |
| UI components | Component tests | RTL/Playwright | Critical flows |
| E2E flows | End-to-end | Playwright/Cypress | Top 5 user flows |
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.
- 1mo ago First seen · 152 lines · 11 tokens per session scan A eb7f604db088
qa is an agent published in the GitHub repository erniker/understudy (2 stars, last pushed 20d ago), licensed MIT. It adds 11 tokens to every session and 1,354 once invoked, about $0.0000 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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