Borrowing it
Nothing to install: this file belongs to Anantys-oss/koan. 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/Anantys-oss/koan/main/.claude/skills/brain/SKILL.mdgit clone --depth 1 https://github.com/Anantys-oss/koanWrote 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/anantys-oss/koan/brain)<a href="https://agentmods.dev/skills/anantys-oss/koan/brain"><img src="https://agentmods.dev/badge/skills/anantys-oss/koan/brain/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/anantys-oss/koan/brain"><img src="https://agentmods.dev/badge/skills/anantys-oss/koan/brain.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 | $0.00232 | $0.02395 |
| Opus 5.5 | $0.00093 | $0.00958 |
| Sonnet 5.5 | $0.00046 | $0.00479 |
| Haiku 4.5 | $0.00023 | $0.00239 |
Grade A, and why
brain 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 1mo 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.
The source is not reproduced here
Licensed GPL-3.0
The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 1mo ago First seen · 158 lines · 232 tokens per session scan A a8ed638bc63e
brain is a skill published in the GitHub repository Anantys-oss/koan (47 stars, last pushed 8d ago), licensed GPL-3.0. It adds 232 tokens to every session and 2,395 once invoked, about $0.0009 per session on Opus 5.5. 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.
Other skills, from other repositories
octo-summary
Read, create, find, and cite Octo summaries through octo-cli. Use when an agent needs to create an owner-only summary from explicit channels, discover summaries visible to its bot owner, inspect one summary, retrieve its current body, or ground an answer in returned citation metadata. Load after octo-shared.
but-agentlog
Use for prompts like "get context for branch", "catch up on this branch", "recover branch context", or "what prior agent work happened here". Skim prior agent work from but agentlog captures for a GitButler branch, review / pull request / merge request, or change. Prefer this over generic git branch/diff inspection…
issue-triage
Triage GitHub issues through the canonical state machine — classify, label, deduplicate, request missing info, write agent briefs, and manage stale issues. Use on demand or on a triage cron.
auto-git-commiter
Use when automatically commit and push OpenClaw changes to GitHub. Enable continuous improvement with automatic versioning, changelogs, and deployment-ready commits. Use when working with auto git commiter.
issue-answer
Answer a question directly — a sourced, neutral reply to an information/explanation/comparison request, from a GitHub issue or a Slack thread. Research repo docs and the web, output the answer, label question (GitHub only), leave open. Never write an agent brief, mark ready-for-agent, or change code.
issue-comment
Handle a non-build maintainer comment on an issue or PR — close, reopen, label, dedupe, answer a brief question, or triage. Action-only; redirect anything that needs code changes to /build.