ruchy-book: Instructions file for Claude Code

CLAUDE.md

ruchy-book CLAUDE.md is an instructions file for Claude Code from paiml/ruchy-book. It costs 10,214 tokens per session, scanned C, original, MIT.

Implementation instructions for the Ruchy programming-language book. They require test-driven documentation (TDD), meaning examples are tested before they are written into the documentation, plus automated quality checks and full coverage.

In plain words
What is it for?
Use them when adding chapters or examples, running the Ruchy test workflow, checking quality with PMAT, or preparing commits.
Why use it?
They prevent the book from promising code that does not work and define the checks required before changes can be committed.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions CLAUDE.md; mentions Claude Code.

This is paiml/ruchy-book's own configuration. It tells Claude Code how to work on ruchy-book itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything ruchy-book configures →

Not installable: its command points at a path on the author’s own machine, so it runs nowhere else. The line is /home/noah/src/ruchy.

Reuse

Borrowing it

Nothing to install: this file belongs to paiml/ruchy-book. 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/paiml/ruchy-book/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/paiml/ruchy-book

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.

agentmods badge for ruchy-book CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/paiml/ruchy-book/claude-md.svg)](https://agentmods.dev/instructions/paiml/ruchy-book/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/paiml/ruchy-book/claude-md"><img src="https://agentmods.dev/badge/instructions/paiml/ruchy-book/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 10,214 This file is loaded in full into every session.
When invoked 10,214 The same file — it is already loaded in full.
Security scan C 1 finding. Scan, not verified.
Origin original 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.10214 $0.10214
Opus 5 $0.05107 $0.05107
Sonnet 5 $0.02043 $0.02043
Haiku 4.5 $0.01021 $0.01021

Measured 6d ago against content hash bfdd9e8f6b89, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade C, and why

ruchy-book CLAUDE.md scanned grade C 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 6d 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.

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

rm -rf book/
CLAUDE.md · 1,269 lines

How it starts

The opening of the file, as written. The whole thing — 1,269 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md - Ruchy Book Implementation Protocol

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Prime Directive

Generate correct documentation where every example compiles on first attempt. Quality is built-in, not bolted-on.

Core Principles (Toyota Way)

  • Kaizen (改善): Continuous incremental improvement - one chapter at a time
  • Genchi Genbutsu (現地現物): Go and see - test every example in real REPL before documenting
  • Jidoka (自働化): Quality at the source - automated validation prevents broken examples

MANDATORY Development Approach (BLOCKING - Not Optional)

A. Test-Driven Documentation (TDD)

  • ALL work must be TDD: Every example written test-first, then documentation
  • NO exceptions: Documentation follows working code, never precedes it
  • Immediate feedback: Tests run continuously during development

B. Professional Quality Gates with PMAT

  • ALL work must pass PMAT TDG: Use pmat analyze for quality verification
  • Quality score requirement: Minimum A+ grade on all code examples
  • BLOCKING gate: No commits allowed without PMAT approval

C. 100% Coverage Approach Only

  • Complete coverage mandatory: Every code path tested and documented
  • Use ruchy coverage tool: ruchy coverage [file] validates 100% coverage
  • No partial examples: All examples must be complete, working programs

D. 19-Tool Comprehensive Testing (MANDATORY) - TICKET-018 + TICKET-020

  • Use ALL 19 ruchy tools: MANDATORY for every example
  • Core execution (3): run, compile, wasm
  • Quality analysis (15): check, test, fmt, lint, provability, runtime, score, quality-gate, optimize, prove, doc, bench, ast, coverage, mcp
  • Debugging (1) 🆕: ruchydbg validate, ruchy --trace, ruchy dataflow:debug
  • Tool-driven workflow: Let tools guide development and validation
  • Quality verification: Pre-commit hook enforces comprehensive testing (8 gates including debugging)

Read the full file on GitHub · 1,269 lines

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.

  1. 6d ago First seen · 1,269 lines · 10,214 tokens per session scan C bfdd9e8f6b89

Subscribe to this mod's changes

ruchy-book CLAUDE.md is an instructions file published in the GitHub repository paiml/ruchy-book (11 stars, last pushed today), licensed MIT. It adds 10,214 tokens to every session, about $0.0511 per session on Opus 5. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other instructions, from other repositories

next.js AGENTS.md

AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.

vercel/next.js · 7,296 tokens

codex AGENTS.md

AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.

openai/codex · 5,182 tokens

vscode buildNext.instructions.md

Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).

microsoft/vscode · 6,785 tokens

vscode oss-third-party-notices.instructions.md

Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).

microsoft/vscode · 5,001 tokens

langchain AGENTS.md

AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.

langchain-ai/langchain · 4,469 tokens

spec-kit AGENTS.md

AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.

github/spec-kit · 7,104 tokens