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 skills/lootlog/monorepo/tddnpx skills add lootlog/monorepo --skill tddgit clone --depth 1 https://github.com/lootlog/monorepoWrote 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/lootlog/monorepo/tdd)<a href="https://agentmods.dev/skills/lootlog/monorepo/tdd"><img src="https://agentmods.dev/badge/skills/lootlog/monorepo/tdd.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 | $0.00060 | $0.00376 |
| Opus 5 | $0.00030 | $0.00188 |
| Sonnet 5 | $0.00012 | $0.00075 |
| Haiku 4.5 | $0.00006 | $0.00038 |
Grade A, and why
tdd 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
Test-driven development
Make the intended behavior executable before changing production code.
Workflow
- Identify the intended behavior, current behavior, affected public seam, and smallest observable reproduction.
- Choose the narrowest existing test layer that can express the behavior. Prefer Vitest unit, component, or integration patterns already used by that workspace.
- Add one focused failing test. Assert behavior, not private implementation.
- Run it and confirm that it fails for the intended reason.
- Make the smallest production change that passes the test.
- Run the focused test again, then relevant adjacent tests, typecheck, and lint in proportion to the change.
- Refactor only while the tests remain green.
When a failing test is impractical
Do not build a large harness, mock most of the system, or introduce brittle timing merely to claim TDD. State why a focused failing test is not practical and use the closest executable check: a targeted script, an existing integration path, browser automation against the running app, a response assertion, or generated-output comparison.
Guardrails
- Do not change assertions to bless incorrect behavior.
- Do not test private functions when a public seam exists.
- Mock only boundaries that cannot run locally.
- Keep regression coverage specific to the defect.
- For flaky behavior, first make the signal deterministic or measure its reproduction rate.
Report
Name the failing-before evidence, the passing-after evidence, and every adjacent check performed. If no red test was practical, report the substitute evidence explicitly.
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.
- 5d ago First seen · 35 lines · 60 tokens per session scan A 1dbd8aa4a620
tdd is a skill published in the GitHub repository lootlog/monorepo (10 stars, last pushed today), licensed MIT. It adds 60 tokens to every session and 376 once invoked, about $0.0003 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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