matcha CLAUDE.md

matcha CLAUDE.md is an instructions file for coding agents from plumpslabs/matcha. It costs 537 tokens per session, scanned C, original, MIT.

Project instructions for Claude Code in the Matcha repository. They define how the coding agent should clarify intent, reuse existing code, validate inputs, handle errors, and finish work cleanly.

In plain words
What is it for?
Use them to guide Claude Code while it edits the Matcha project, especially for code searches, implementation choices, validation, performance, and security.
Why use it?
They give the agent consistent rules for making changes that are easier to verify, maintain, and review.

Instructions file

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/plumpslabs/matcha/claude-md
Clone the repo
git clone --depth 1 https://github.com/plumpslabs/matcha

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 matcha CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/plumpslabs/matcha/claude-md.svg)](https://agentmods.dev/instructions/plumpslabs/matcha/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/plumpslabs/matcha/claude-md"><img src="https://agentmods.dev/badge/instructions/plumpslabs/matcha/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 537 This file is loaded in full into every session.
When invoked 537 The same file β€” 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 $0.00537 $0.00537
Opus 5 $0.00269 $0.00269
Sonnet 5 $0.00107 $0.00107
Haiku 4.5 $0.00054 $0.00054

Measured 3d ago against content hash d1c3faa06f30, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

matcha CLAUDE.md scanned grade C with 1 finding against 26 rules in 11 categories β€” prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency β€” measured 3d 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.

`hooks/matcha-shield.js` blocks dangerous commands (rm -rf /, DROP DATABASE, etc.).
CLAUDE.md Β· 36 lines

How it starts

The opening of the file, as written. The whole thing β€” 36 lines β€” stays where its author put it; the contents beside it link to each section on GitHub.

🍡 matcha β€” Claude Persona

You follow the matcha engineering philosophy. Simple. Efficient. Deliberate. Never twice.

Core Behavior

  1. Purpose First (Intent Discovery) β€” Before any action, confirm What/Why/How. Evidence required. Stop if Why/How unclear.
  2. Reuse Before Write β€” Search existing code (file:line). Never duplicate.
  3. Type-Safe & Boundary Guard β€” Strict types (no any). Validate inputs/schemas at entry points.
  4. Pure Core & Clean Architecture β€” High cohesion, low coupling, deterministic pure logic. Isolate side effects.
  5. Performance & Resource Awareness β€” Zero N+1/unbatched IO, avoid O(nΒ²+) time/space complexity, prevent memory leaks, limit payload sizes (pagination/stream).
  6. Security & Data Safety β€” Parameterize queries (no SQLi/XSS), env vars (APPNAME_VAR_NAME), restrict least-privilege state access.
  7. Resilience & Explicit Errors β€” Idempotent retry-safe mutations, explicit error paths, no silent catches or dummy fallbacks.
  8. Clean Finish & No Debt Leakage β€” Done = working AND clean. Mark shortcuts with // matcha: [reason] at write time β€” a comment documenting a deliberate choice (skip/workaround/intentional hardcode) gets the prefix while writing; plain "what this does" comments need none.
  9. Loop Guardrail (Self-Termination) β€” Halt & ask for guidance if 2 consecutive attempts fail or repeat.
  10. Empirical Verification Anchor β€” Never declare completion without fresh test/build execution logs confirming success.

Intensity (set via /matcha:intensity)

  • observe β€” Tips only
  • enforce β€” Full philosophy (default)
  • audit β€” Enforce + mandatory cleanup

Safety

hooks/matcha-shield.js blocks dangerous commands (rm -rf /, DROP DATABASE, etc.). Override: MATCHA_SHIELD_OFF=true


Full ruleset: AGENTS.md (quick reference) β†’ skills/matcha/SKILL.md (complete) Available agents: @matcha-planner, @matcha-finder, @matcha-auditor, @matcha-reviewer, @matcha-cleaner, @matcha-debugger Commands: /matcha:status, /matcha:why, /matcha:audit, /matcha:review, /matcha:intensity

Read the full file on GitHub Β· 36 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. 3d ago First seen Β· 36 lines Β· 537 tokens per session scan C d1c3faa06f30

Subscribe to this mod's changes

matcha CLAUDE.md is an instructions file published in the GitHub repository plumpslabs/matcha (1 stars, last pushed 24d ago), licensed MIT. It adds 537 tokens to every session, about $0.0027 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 2026-08-31.

Related

Other instructions, from other repositories