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/fallow-rs/fallow/coverage-loopnpx skills add fallow-rs/fallow --skill coverage-loopgit clone --depth 1 https://github.com/fallow-rs/fallowWhat 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 | $0.00029 | $0.00141 |
| Opus 5 | $0.00015 | $0.00071 |
| Sonnet 5 | $0.00006 | $0.00028 |
| Haiku 4.5 | $0.00003 | $0.00014 |
Grade A, and why
coverage-loop 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 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.
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
Coverage loop
- Capture a coverage baseline with the repository-supported command.
- Select uncovered behavior by risk, not by easiest lines.
- Add behavior-focused tests that survive refactors.
- Re-run targeted tests and the same coverage command.
- Keep only tests that improve meaningful coverage or lock a real invariant.
- Repeat until the selected risk area is covered or remaining gaps require a separate design change.
- Run
review.
Do not add assertions that merely execute code without checking behavior.
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 First seen · 18 lines · 29 tokens per session scan A 3ff03f2cac03
coverage-loop is a skill published in the GitHub repository fallow-rs/fallow (4,429 stars, last pushed yesterday), licensed MIT. It adds 29 tokens to every session and 141 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.
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