Borrowing it
Nothing to install: this file belongs to houtini-ai/metacog. 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/houtini-ai/metacog/main/CLAUDE.mdgit clone --depth 1 https://github.com/houtini-ai/metacogWrote 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/houtini-ai/metacog/claude-md)<a href="https://agentmods.dev/instructions/houtini-ai/metacog/claude-md"><img src="https://agentmods.dev/badge/instructions/houtini-ai/metacog/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/houtini-ai/metacog/claude-md"><img src="https://agentmods.dev/badge/instructions/houtini-ai/metacog/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 | $0.00889 | $0.00889 |
| Opus 5 | $0.00445 | $0.00445 |
| Sonnet 5 | $0.00178 | $0.00178 |
| Haiku 4.5 | $0.00089 | $0.00089 |
Grade A, and why
metacog 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 9d 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 — 67 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Metacog
Claude Code hook plugin that gives the agent real-time awareness of its own cognitive state.
Architecture
Two hooks, one state file:
src/hook.js(PostToolUse) - fires after every tool call, evaluates 7 senses, outputs a signal only when something is abnormal. Silent exit 0 = everything fine. JSON stdout = signal for the agent.src/digest-inject.js(UserPromptSubmit) - fires on every user message. First message of session: injects behavioural digest + session retrospective. Every message: captures task fingerprint for drift detection, records user interaction metadata..claude/metacog.state.json- ephemeral rolling window of last 20 actions. Written by hook.js, read by both hooks. Reset on session change. Do not persist or version control this file.
The 7 senses (src/senses/)
| Sense | File | What it watches |
|---|---|---|
| O2 | o2.js | Token velocity vs baseline |
| Chronos | chronos.js | Time and steps since last user interaction |
| Nociception | nociception.js | Consecutive similar errors (Layer 1 + Layer 2 escalation) |
| Spatial | spatial.js | git grep for importers after writes |
| Vestibular | vestibular.js | Repeated identical actions |
| Echo | echo.js | Write streaks without test runs, self-test pattern |
| Drift | drift.js | Recent actions diverging from task fingerprint |
Key principles when modifying senses
- Silent by default. A sense that fires too often is worse than one that never fires. No news is good news.
- Every sense has a cooldown. After firing, suppress for N turns. One nudge is enough.
- Graceful degradation. Any error in any sense must be caught. If the hook crashes, the agent loses proprioception but keeps working. Never let the nervous system kill the brain.
- Inform, don't command. Layer 1 signals are observations the agent can dismiss. Only Layer 2 (nociception escalation) forces structured reflection, and it earns that right by requiring repeated failure first.
- Subagent awareness. Agent tool calls are delegations, not grinding. Suppress O2 and Chronos on delegation returns.
- Cooldown ticking. If you add a new cooldown field to state, you must also tick it down in
state.js:appendAction().
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.
- 9d ago First seen · 67 lines · 889 tokens per session scan A 6ea20a04a8ae
metacog CLAUDE.md is an instructions file published in the GitHub repository houtini-ai/metacog (5 stars, last pushed 4mo ago), licensed Apache-2.0. It adds 889 tokens to every session, about $0.0044 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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