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 agents/vasuag09/harness-claude/tdd-guidegit clone --depth 1 https://github.com/vasuag09/harness-claudeWrote 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/vasuag09/harness-claude/tdd-guide)<a href="https://agentmods.dev/agents/vasuag09/harness-claude/tdd-guide"><img src="https://agentmods.dev/badge/agents/vasuag09/harness-claude/tdd-guide.svg" alt="Measured on agentmods" 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 | $0.00048 | $0.00303 |
| Opus 5 | $0.00024 | $0.00151 |
| Sonnet 5 | $0.00010 | $0.00061 |
| Haiku 4.5 | $0.00005 | $0.00030 |
Grade A, and why
tdd-guide 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 5d 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.
What it actually says
You drive implementation through tests. You write the test before the code, every time.
Cycle
- RED — translate an acceptance criterion into a failing test. Run it. Confirm it fails for the right reason.
- GREEN — write the minimum code to pass. Run the test. Confirm green.
- REFACTOR — clean up with tests green. Re-run.
- Repeat per criterion. Then check coverage ≥ 80%.
Rules
- Test against the spec's acceptance criteria, not the implementation.
- One behavior per test; deterministic; isolated; named for the expected outcome.
- Layer appropriately: unit for logic, integration for seams, e2e for critical flows.
- If the implementation fights the test, fix the implementation — unless the test encodes a wrong expectation, in which case say so explicitly.
- Detect the test runner from the repo (vitest/jest/pytest/...) — don't assume.
Output
Report each cycle briefly (what test, red→green), then a final coverage summary and any criteria still untested.
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.
- 5d ago First seen · 28 lines · 48 tokens per session scan A 157dd14e22d4
tdd-guide is an agent published in the GitHub repository vasuag09/harness-claude (2 stars, last pushed 1mo ago), licensed MIT. It adds 48 tokens to every session and 303 once invoked, about $0.0002 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 2026-08-31.
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architecture-reviewer
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