What is cursor-rulebook CLAUDE.md?

Instructions for Claude Code projects that document the project, common commands, and how to validate its rules. Strict validation treats warnings as errors.

Explaining a project, recording routine commands, and checking rule files with normal or strict validation.

They give the agent consistent project guidance and catch rule problems before the rules are used.

How rrudol/cursor-rulebook configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to rrudol/cursor-rulebook. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/rrudol/cursor-rulebook/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/rrudol/cursor-rulebook

Made for: Claude Code.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/rrudol/cursor-rulebook/claude-md/github.svg)](https://agentmods.dev/instructions/rrudol/cursor-rulebook/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/rrudol/cursor-rulebook/claude-md"><img src="https://agentmods.dev/badge/instructions/rrudol/cursor-rulebook/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/rrudol/cursor-rulebook/claude-md"><img src="https://agentmods.dev/badge/instructions/rrudol/cursor-rulebook/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 827 This file is loaded in full into every session.

When invoked 827 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin unknown No closer match found in the catalogue.

Token cost

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	$0.00827	$0.00827
Opus 5.5	$0.00331	$0.00331
Sonnet 5.5	$0.00165	$0.00165
Haiku 4.5	$0.00083	$0.00083

Measured 2mo ago against content hash 4333efe1ff14, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

cursor-rulebook 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 2mo 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.

CLAUDE.md · 101 lines

The source is not reproduced here

No licence file

Read it on GitHub

Changes

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.

2mo ago First seen · 101 lines · 827 tokens per session scan A 4333efe1ff14

Subscribe to this mod's changes

cursor-rulebook CLAUDE.md is an instructions file published in the GitHub repository rrudol/cursor-rulebook (3 stars, last pushed 1y ago), with no licence file. It adds 827 tokens to every session, about $0.0033 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 2026-08-31.

ai-tools coding-standards cursor developer-productivity

cursor-rulebook CLAUDE.md next to 6 instructions from other repositories
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cursor-rulebook: Instructions file for Claude Code