Borrowing it
Nothing to install: this file belongs to spruikco/fat-agent-skill. 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/spruikco/fat-agent-skill/master/CLAUDE.mdgit clone --depth 1 https://github.com/spruikco/fat-agent-skillWrote 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/instructions/spruikco/fat-agent-skill/claude-md)<a href="https://agentmods.dev/instructions/spruikco/fat-agent-skill/claude-md"><img src="https://agentmods.dev/badge/instructions/spruikco/fat-agent-skill/claude-md.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 | $0.00736 | $0.00736 |
| Opus 5 | $0.00368 | $0.00368 |
| Sonnet 5 | $0.00147 | $0.00147 |
| Haiku 4.5 | $0.00074 | $0.00074 |
Grade A, and why
fat-agent-skill CLAUDE.md 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 7d 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 — 48 lines — stays where its author put it; the contents beside it link to each section on GitHub.
FAT Agent — Project Conventions
What This Is
FAT Agent is a Claude Plugin distributed via a marketplace. The repo root is the marketplace; the plugin lives under plugins/fat-agent/.
File Roles
plugins/fat-agent/skills/fat-agent/SKILL.md— The skill definition. Claude reads this on trigger. YAML frontmatter controls activation.plugins/fat-agent/scripts/— Python helpers that Claude executes via bash during audits.plugins/fat-agent/references/— Deep-dive docs Claude loads on-demand when it needs specifics.plugins/fat-agent/references/platform-fixes/— One file per hosting platform (Netlify, Vercel, etc.).plugins/fat-agent/references/framework-fixes/— One file per framework (Next.js, Astro, etc.).plugins/fat-agent/evals/— Test cases for validating skill behaviour.plugins/fat-agent/assets/— Templates and static assets.plugins/fat-agent/commands/fat-audit.md— The/fat-auditslash command..claude-plugin/marketplace.json— Marketplace manifest.plugins/fat-agent/.claude-plugin/plugin.json— Plugin manifest.
Conventions
- British English spelling throughout (analyse, colour, prioritise).
- Markdown for all docs — no HTML in reference files unless demonstrating HTML code.
- Python scripts use stdlib only (no pip dependencies). Must work on Python 3.8+.
- Reference docs follow the pattern: explanation, code example, scoring table.
- Platform/framework docs should include complete, copy-pasteable config examples.
- SKILL.md sections are numbered (1.1, 1.2, ..., 1.9). New audit checks go after 1.9.
Testing
python plugins/fat-agent/scripts/analyse-html.py <file.html>— outputs JSON report.python plugins/fat-agent/scripts/analyse-html.py --url https://example.com <file.html>— enables mixed content detection.python plugins/fat-agent/scripts/analyse-html.py < file.html— reads from stdin.python plugins/fat-agent/scripts/calculate-score.py <report.json>— scores an analysis report.- Pipeline:
python plugins/fat-agent/scripts/analyse-html.py page.html | python plugins/fat-agent/scripts/calculate-score.py python plugins/fat-agent/scripts/generate-badge.py <scores.json>— generates an SVG score badge.python plugins/fat-agent/scripts/generate-badge.py scores.json --category seo— badge for a specific category.python plugins/fat-agent/scripts/generate-badge.py scores.json --output badge.svg— write to file.- Full pipeline:
python plugins/fat-agent/scripts/analyse-html.py page.html | python plugins/fat-agent/scripts/calculate-score.py | python plugins/fat-agent/scripts/generate-badge.py --output badge.svg python plugins/fat-agent/scripts/test_fat_agent.py— runs the full test suite (630 tests).
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.
- 7d ago First seen · 48 lines · 736 tokens per session scan A 5eb8b079af91
fat-agent-skill CLAUDE.md is an instructions file published in the GitHub repository spruikco/fat-agent-skill (38 stars, last pushed 20d ago), licensed MIT. It adds 736 tokens to every session, about $0.0037 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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