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 agentmods add commands/policyengine/policyengine-claude/write-testsgit clone --depth 1 https://github.com/PolicyEngine/policyengine-claudeWhat 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 | $0.00015 | $0.00772 |
| Opus 5 | $0.00008 | $0.00386 |
| Sonnet 5 | $0.00003 | $0.00154 |
| Haiku 4.5 | $0.00002 | $0.00077 |
Grade A, and why
write-tests 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 2d 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.
How it starts
The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Write unit tests
Write well-structured unit tests that match the conventions the target repository actually uses — discover them from existing tests, never impose an external template.
Important: This command is for frontend apps, APIs, SDKs, and standalone tools. It is
NOT for country model packages (policyengine-us, policyengine-uk, etc.), which use
YAML-based tests — for those, load the policyengine-model-development skill
(references/tests.md) and use the test-creator agent instead.
Step 1: Identify target files
Ask the user which file(s) to test. If none specified, ask:
Which source file(s) should I write tests for?
Read each source file thoroughly before writing any tests. Understand:
- All exported functions, classes, components, and their signatures
- Happy path behavior
- Error handling and edge cases
- Dependencies that need mocking
Step 2: Detect the framework and the repo's real conventions
| Indicator | Framework |
|---|---|
vitest in package.json |
Vitest |
pytest in pyproject.toml |
pytest |
jest in package.json |
Jest (legacy repos) |
Then read 2-3 existing test files near your target and copy their observed conventions:
directory layout, file naming, describe/test phrasing, mock style, and any shared
test-utils imports. In policyengine-app-v2, for example, tests live under
app/src/tests/ as Name.test.ts(x) — plain describe/test names, no
given/when/then scaffolding, no separate fixtures tree. Other repos differ; the
existing tests are the spec. If a project-level test CLAUDE.md or config exists, it
overrides everything here.
Step 3: Write test files
Place and name new tests exactly as the repo's existing tests do. Whatever the naming style, every test file must cover:
- Happy path
- Edge cases (zero, empty, null, boundary values)
- Expected error/failure paths
- Component tests: user-visible behavior (render output, interactions), not implementation details
Extract shared constants/mocks into the repo's established pattern (inline consts at
the top of the test file, or the repo's test-utils module — whichever neighbors use).
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.
- 2d ago First seen · 93 lines · 15 tokens per session scan A fff40f6bd0a0
write-tests is a command published in the GitHub repository PolicyEngine/policyengine-claude (31 stars, last pushed 7d ago), licensed MIT. It adds 15 tokens to every session and 772 once invoked, about $0.0001 per session on Opus 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 2026-08-30.
Other commands, from other repositories
checklist
Generate a custom checklist for the current feature based on user requirements.
clarify
Identify underspecified areas in the current feature spec by asking up to 5 highly targeted clarification questions and encoding answers back into the spec.
specify
Create or update the feature specification from a natural language feature description.
analyze
Perform a non-destructive cross-artifact consistency and quality analysis across spec.md, plan.md, and tasks.md after task generation.
converge
Assess the current codebase against the feature's spec, plan, and tasks, then append any remaining unbuilt work as new tasks to tasks.md so implement can complete it.
implement
Execute the implementation plan by processing and executing all tasks defined in tasks.md.