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.
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 skills add tjboudreaux/cc-thinking-skills --skill thinking-model-routergit 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/skills/tjboudreaux/cc-thinking-skills/thinking-model-router)<a href="https://agentmods.dev/skills/tjboudreaux/cc-thinking-skills/thinking-model-router"><img src="https://agentmods.dev/badge/skills/tjboudreaux/cc-thinking-skills/thinking-model-router/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/tjboudreaux/cc-thinking-skills/thinking-model-router"><img src="https://agentmods.dev/badge/skills/tjboudreaux/cc-thinking-skills/thinking-model-router.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- 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 | $0.00032 | $0.01402 |
| Opus 5 | $0.00016 | $0.00701 |
| Sonnet 5 | $0.00006 | $0.00280 |
| Haiku 4.5 | $0.00003 | $0.00140 |
Grade A, and why
thinking-model-router 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 12d 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 — 90 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Model Router
Core rule: Prefer NONE or one primary skill. Route by mechanism fit, not habit. Combine only when roles are distinct and necessary.
When to Use
- The right thinking skill is unclear and you would otherwise guess or stack tools.
- Several catalog skills seem plausible and you need a single primary (or explicit NONE).
- High-stakes work where a wrong frame is costly and a quick domain×type match helps.
When NOT to Use
- The match is already known or obvious ("where's the bottleneck?" → theory-of-constraints) — invoke that skill directly; do not route for show.
- The task is routine implementation with no analytical unknown — reason directly (NONE).
- You are mid-execution of an agreed plan and only need the next concrete step.
- The ask is outside this catalog (pure coding syntax, tool ops with no judgment call) — NONE.
Invoking a Model (Skill IDs)
The router outputs bare slugs (e.g. id: five-whys-plus). Invoke a routed skill with the Skill tool using the exact ID thinking-skills:thinking-<slug> — never invent a slug not cited in Procedure. NONE means no invocation.
Procedure
- Short-circuit. If one skill clearly fits by mechanism, return that skill alone. If no skill clearly improves the work, return NONE and reason directly. Stop.
- Characterize. Record domain (coding, architecture, product, strategy, personal, abstract, risk, innovation) and problem type (diagnose, decide, understand, create, evaluate, predict, optimize). Note constraints: time, information, stakes, reversibility, complexity.
- Candidate by type defaults (override when constraints demand). Keep only active catalog skills:
- Diagnose → five-whys-plus or scientific-method (kepner-tregoe if IS/IS-NOT matrix needed)
- Decide → reversibility first; then opportunity-cost or probabilistic
- Understand → systems (map-territory if model-vs-reality gap; cynefin if approach domain unclear)
- Create → first-principles (triz for contradictions; effectuation for means-driven; via-negativa for remove-first)
- Evaluate → steel-manning (socratic if assumptions/definitions are the unknown)
- Predict → probabilistic
- Optimize → theory-of-constraints (ooda under time pressure; bounded-rationality for search stop)
- Risk / "what fails?" → pre-mortem or red-team; margin-of-safety for buffers
- Product "what to build?" → jobs-to-be-done
- Competence / durability → circle-of-competence, lindy-effect
- Controlled hypothetical → thought-experiment
- Multi-lens only after one primary fails a blind-spot check → model-combination
- Select with criteria (satisficing). Score only if 2+ candidates remain or stakes make a forced default unsafe. Rate each criterion 1–5 (1 = absent/wrong fit; 3 = usable with gaps; 5 = direct fit): problem fit (30%), available inputs (20%), time to apply (15%), stakeholder usability (15%), competence to apply correctly (20%). A route must score problem fit ≥4 and weighted total ≥3.5; otherwise return NONE. For totals within 0.25, prefer fewer inputs and shorter execution; if still tied, choose NONE unless the skills answer distinct complementary questions.
- Multi-skill only as exception. Add a second or third skill only when each has a distinct complementary role the primary leaves open. Cap at three. Prefer sequential over parallel. Near-neighbors and synonyms do not stack. For composition patterns, hand off to model-combination after naming the primary.
- Exit. State abandon signals (forced fit, ignored factors, no insight ~15 minutes). On mismatch, re-route once or fall back to NONE — never force a frame.
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.
- 12d ago First seen · 90 lines · 32 tokens per session scan A b230ab2d3dd4
thinking-model-router is a skill published in the GitHub repository tjboudreaux/cc-thinking-skills (1,306 stars, last pushed 1mo ago), licensed MIT. It adds 32 tokens to every session and 1,402 once invoked, about $0.0002 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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