Monty is a minimal Python interpreter written in Rust that runs AI-generated code in a restricted environment without direct filesystem, environment-variable, or network access. It is for AI agents that need to execute Python and type-checking tasks while allowing developers to control which host functions and objects the code can use, and the catalogue entries integrate it into agent workflows.
Borrowing it
Nothing to install: this file belongs to pydantic/monty. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/pydantic/monty/main/.agents/skills/coverage/SKILL.mdgit clone --depth 1 https://github.com/pydantic/montyWrote 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/pydantic/monty/coverage)<a href="https://agentmods.dev/skills/pydantic/monty/coverage"><img src="https://agentmods.dev/badge/skills/pydantic/monty/coverage/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/skills/pydantic/monty/coverage"><img src="https://agentmods.dev/badge/skills/pydantic/monty/coverage.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00029 | $0.00256 |
| Opus 5.5 | $0.00012 | $0.00102 |
| Sonnet 5.5 | $0.00006 | $0.00051 |
| Haiku 4.5 | $0.00003 | $0.00026 |
Grade A, and why
coverage 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.
What it actually says
Coverage
Fetch line-by-line coverage information from Codecov for a GitHub pull request.
Instructions
Use this skill to check code coverage for your changes before merging.
Current branch (auto-detect PR)
uv run scripts/codecov_diff.py
This auto-detects the org, repo, and PR number using the gh CLI based on the current branch.
Specific PR number
uv run scripts/codecov_diff.py 123
Output
The script outputs:
- PR title and state
- HEAD coverage (overall coverage on the branch)
- Patch coverage (coverage of changed lines only)
- Coverage change (+/- percentage)
- Per-file breakdown with:
- Missed line count
- Patch coverage percentage
- Specific uncovered line numbers (as ranges like
45-48, 52, 60-65) - Partial coverage line numbers
Requirements
- The
ghCLI must be installed and authenticated for auto-detection - The PR must have Codecov coverage data uploaded
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 Changed · +1 lines 73e5c742f440
- 2mo ago First seen · 45 lines · 29 tokens per session scan A 1b2fbe3a4f76
coverage is a skill published in the GitHub repository pydantic/monty (8,801 stars, last pushed today), licensed MIT. It adds 29 tokens to every session and 256 once invoked, about $0.0001 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 2026-08-30.
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