Borrowing it
Nothing to install: this file belongs to ericovis/cervo. 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/ericovis/cervo/main/CLAUDE.mdgit clone --depth 1 https://github.com/ericovis/cervoWrote 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/ericovis/cervo/claude-md)<a href="https://agentmods.dev/instructions/ericovis/cervo/claude-md"><img src="https://agentmods.dev/badge/instructions/ericovis/cervo/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/ericovis/cervo/claude-md"><img src="https://agentmods.dev/badge/instructions/ericovis/cervo/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 | $0.07616 | $0.07616 |
| Opus 5.5 | $0.03046 | $0.03046 |
| Sonnet 5.5 | $0.01523 | $0.01523 |
| Haiku 4.5 | $0.00762 | $0.00762 |
Grade B, and why
cervo CLAUDE.md scanned grade B with 1 finding 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.
Asks for rootmediumPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
handed over with `:U`). Host-side, the runtimes still run as root. If a How it starts
The opening of the file, as written. The whole thing — 458 lines — stays where its author put it; the contents beside it link to each section on GitHub.
cervo
A demo app for managing static website hosting on a shared VPS, built as an MCP server with FastMCP. Claude Code is the AI/chat interface used to exercise and test the server's tools during development. The whole environment — dev and production alike — runs from docker-compose: caddy is the front door, a worker process runs deployments, and mailcatcher stands in for SMTP in development.
Running
Prerequisite: Docker (with Compose). uv is used for lint/format and can run the test suite directly.
bin/dev # docker compose up -d — the whole environment
The stack is four services, all sharing the .data volume at /mnt/data:
app— the MCP server and the public website, one service: uvicorn withWEB_CONCURRENCYworker processes (default 1) importingcervo.asgi— MCP runs stateless, so any worker serves any request. Publishes no port; caddy reverse-proxies it athttp://localhost— the homepage (with docs at/docs) — and the MCP endpoint stayshttp://localhost/mcp.worker— the job worker (cervo-worker): one container runningWORKER_CONCURRENCYpolling threads (default 1) — claiming is atomic in the database, so more threads never double-run a job. Boots first, creates the database tables, and queues the reconciliation of caddy's config (once, before any thread polls).caddy— the front door on ports 80/443. There is no config file anywhere: it runscaddy run --resumewithCADDY_ADMIN=0.0.0.0:2019, so it boots holding whatever it last saved ($XDG_CONFIG_HOME/caddy/autosave.json—/tmp/caddyin dev, thecaddy-configvolume in production) and everything it serves — cervo's own reverse proxy and every hosted site, athttp://{slug}.localhost— is written into its running config by the worker over its unauthenticated admin API (caddy:2019, reachable only on the compose network). On a fresh checkout that means a few seconds serving nothing, between a caddy with no autosave and the worker's first sync; that is accepted, not a bug. Caddy is handed none of cervo's settings — it is told what to serve.mail— mailcatcher (SMTP on 1025, web UI at http://localhost:1080). Development mail — the sign-in codes — goes here, not to real SMTP.
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 Changed · +94 lines · +1,785 tokens per session 51bc10941ae3
- 2mo ago Changed · +32 lines · +590 tokens per session 4cff590944dd
- 2mo ago First seen · 332 lines · 5,241 tokens per session scan B fb5d23514dab
cervo CLAUDE.md is an instructions file published in the GitHub repository ericovis/cervo (0 stars, last pushed 1mo ago), licensed MIT. It adds 7,616 tokens to every session, about $0.0305 per session on Opus 5.5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
cervo CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| cervo CLAUDE.mdericovis/cervo | Instructions file | 0 | 1mo ago | MIT | B | 7,616 | Claude Code |
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