Claude Code Thinking Skills is a catalogue of 28 portable skills that give coding agents structured procedures for reasoning about decisions, diagnosis, risk, strategy, and related problems. It is intended for Claude Code, GitHub Copilot, Codex, Cursor, and other tools that support Agent Skills.
Borrowing it
Nothing to install: this file belongs to tjboudreaux/cc-thinking-skills. 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/tjboudreaux/cc-thinking-skills/main/CLAUDE.mdgit clone --depth 1 https://github.com/tjboudreaux/cc-thinking-skillsWrote 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/tjboudreaux/cc-thinking-skills/claude-md)<a href="https://agentmods.dev/instructions/tjboudreaux/cc-thinking-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/tjboudreaux/cc-thinking-skills/claude-md/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/instructions/tjboudreaux/cc-thinking-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/tjboudreaux/cc-thinking-skills/claude-md.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00141 | $0.00141 |
| Opus 5 | $0.00071 | $0.00071 |
| Sonnet 5 | $0.00028 | $0.00028 |
| Haiku 4.5 | $0.00014 | $0.00014 |
Grade A, and why
cc-thinking-skills 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 10d 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
Claude Project Notes
Follow AGENTS.md for repository workflow.
Key project facts:
- Shipped skill count: 28.
thinking-scientific-methodis the shipped hypothesis-differential debugging skill. Do not reintroduce a separate v2 variant.- Eval claims must identify whether they are pre-edit, post-edit, directional, or statistically significant.
- Backups of global Claude state belong in
backups/and must remain uncommitted.
Common verification commands:
node scripts/validate-skills.js
EVAL_RUN=local node evals/run-structural.js
EVAL_RUN=local node evals/run-routing.js
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.
- 10d ago First seen · 18 lines · 141 tokens per session scan A 3680477f3f5a
cc-thinking-skills CLAUDE.md is an instructions file published in the GitHub repository tjboudreaux/cc-thinking-skills (1,293 stars, last pushed 1mo ago), licensed MIT. It adds 141 tokens to every session, about $0.0007 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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