Borrowing it
Nothing to install: this file belongs to mhenke/john-ousterhout-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/mhenke/john-ousterhout-skills/main/CLAUDE.mdgit clone --depth 1 https://github.com/mhenke/john-ousterhout-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/mhenke/john-ousterhout-skills/claude-md)<a href="https://agentmods.dev/instructions/mhenke/john-ousterhout-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/mhenke/john-ousterhout-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/mhenke/john-ousterhout-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/mhenke/john-ousterhout-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 | $0.01790 | $0.01790 |
| Opus 5 | $0.00895 | $0.00895 |
| Sonnet 5 | $0.00358 | $0.00358 |
| Haiku 4.5 | $0.00179 | $0.00179 |
Grade A, and why
john-ousterhout-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 11d 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 — 146 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
Source of truth for the 15 behavioral rules. Copy changes here first. .cursor/rules/aposd-guidelines.mdc mirrors this in its rule body. skills/aposd/SKILL.md uses condensed wording — manually distill changes there, keeping its always-on context footprint small. See docs/adr/005-claude-sk-condensation.md.
APOSD behavioral guidelines for AI coding agents. Merge with project-specific instructions as needed.
Tradeoff: These guidelines bias toward strategic design over tactical speed. For trivial tasks, use judgment.
1. Strategic Over Tactical
Working code isn't enough. Invest in design.
- Every task gets a small design investment: at least one improvement in the surrounding code.
- Watch for the "tactical tornado" — churning out code quickly while accumulating design debt.
- Strategic thinking costs no extra time — it's about how you think, not how long you spend.
- BEFORE implementing any fix, explicitly state the strategic alternative: "Here's the tactical path: [quick fix]. The strategic alternative: [redesign that reduces complexity]. I recommend the strategic approach unless time constraints require otherwise."
- Red flag: If you find yourself using APOSD vocabulary ("deep module," "define errors out of existence") to justify a tactical patch, you're still being tactical. Language doesn't make it strategic — design investment does.
2. Design Deep Modules
Simple interface, powerful implementation.
- Module depth = benefit provided / interface complexity. The ratio should be high.
- If the interface is as complex as the implementation, it's shallow — merge or redesign.
- Diagnostic questions: "How many use cases will this serve?" (if one, too special-purpose). "Is this easy to use for my current need?" (if not, redesign).
3. Information Hiding
Expose only what callers need.
- If implementation details leak into the interface, stop and redesign.
- If the same design decision appears in multiple modules, that's information leakage — consolidate.
- Don't expose internal state unless callers genuinely need it.
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.
- 11d ago First seen · 146 lines · 1,790 tokens per session scan A bbd70d318739
john-ousterhout-skills CLAUDE.md is an instructions file published in the GitHub repository mhenke/john-ousterhout-skills (6 stars, last pushed 2mo ago), licensed MIT. It adds 1,790 tokens to every session, about $0.0089 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 2026-08-31.
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