Zen is a self-hosted notes application that stores Markdown notes inside SQLite and provides full-text search in a single Go binary. It is for people who want a lightweight notes system with low resource use. The catalogue includes agents and an instruction for working with it.
Borrowing it
Nothing to install: this file belongs to sheshbabu/zen. 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/sheshbabu/zen/master/CLAUDE.mdgit clone --depth 1 https://github.com/sheshbabu/zenWrote 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/sheshbabu/zen/claude-md)<a href="https://agentmods.dev/instructions/sheshbabu/zen/claude-md"><img src="https://agentmods.dev/badge/instructions/sheshbabu/zen/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/sheshbabu/zen/claude-md"><img src="https://agentmods.dev/badge/instructions/sheshbabu/zen/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 | $0.00468 | $0.00468 |
| Opus 5.5 | $0.00187 | $0.00187 |
| Sonnet 5.5 | $0.00094 | $0.00094 |
| Haiku 4.5 | $0.00047 | $0.00047 |
Grade A, and why
zen 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 26d 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 AGPL-3.0
The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.
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.
- 26d ago Changed · +1 lines · +26 tokens per session b6909f72f0da
- 1mo ago Changed · -181 lines · -2,243 tokens per session 9c09e6986f2e
- 2mo ago First seen · 225 lines · 2,685 tokens per session scan A 725408e51717
zen CLAUDE.md is an instructions file published in the GitHub repository sheshbabu/zen (1,194 stars, last pushed 4d ago), licensed AGPL-3.0. It adds 468 tokens to every session, about $0.0019 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.
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