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.
npx agentmods add instructions/thedecipherist/claude-code-mastery/claude-mdgit clone --depth 1 https://github.com/TheDecipherist/claude-code-masteryWrote 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/thedecipherist/claude-code-mastery/claude-md)<a href="https://agentmods.dev/instructions/thedecipherist/claude-code-mastery/claude-md"><img src="https://agentmods.dev/badge/instructions/thedecipherist/claude-code-mastery/claude-md.svg" alt="Measured on agentmods" 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 | $0.00676 | $0.00676 |
| Opus 5 | $0.00338 | $0.00338 |
| Sonnet 5 | $0.00135 | $0.00135 |
| Haiku 4.5 | $0.00068 | $0.00068 |
Grade C, and why
claude-code-mastery 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 4d 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.
│ ├── block-dangerous-commands.sh # PreToolUse: blocks rm -rf, etc. How it starts
The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
Overview
This is a documentation and template repository for Claude Code best practices. It contains:
- Educational guide (GUIDE.md) explaining Claude Code configuration
- Ready-to-use templates for CLAUDE.md files, settings.json, and .gitignore
- Example hooks (Python/Bash) for deterministic security enforcement
- Example skills for reusable AI expertise
This is NOT a code project — there is no build system, no tests, no runtime application.
Repository Structure
├── GUIDE.md # Main educational content (~900 lines)
├── templates/ # Copy-and-use templates
│ ├── global-claude.md # Template for ~/.claude/CLAUDE.md
│ ├── project-claude.md # Template for ./CLAUDE.md in any project
│ ├── settings.json # Hook configuration template
│ └── .gitignore # Recommended ignore patterns
├── hooks/ # Security enforcement scripts
│ ├── block-secrets.py # PreToolUse: blocks .env/credentials access
│ ├── block-dangerous-commands.sh # PreToolUse: blocks rm -rf, etc.
│ ├── after-edit.sh # PostToolUse: run formatters
│ ├── end-of-turn.sh # Stop: quality gates
│ └── notify.sh # Desktop notifications
└── skills/ # Packaged AI expertise
├── commit-messages/ # Conventional commit generation
└── security-audit/ # Vulnerability scanning checklist
Key Concepts
Hooks vs CLAUDE.md
CLAUDE.md rules are suggestions that Claude can override under context pressure. Hooks are deterministic enforcement — they always execute.
block-secrets.py: Exit code 2 blocks Read/Edit/Write operations on sensitive filesblock-dangerous-commands.sh: Exit code 2 blocks dangerous Bash patterns
Hook Exit Codes
| Code | Behavior |
|---|---|
| 0 | Allow operation |
| 1 | Error (shown to user only) |
| 2 | Block operation, stderr fed back to Claude |
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.
- 4d ago First seen · 65 lines · 676 tokens per session scan C 56d40b52df13
claude-code-mastery CLAUDE.md is an instructions file published in the GitHub repository TheDecipherist/claude-code-mastery (545 stars, last pushed 3mo ago), licensed MIT. It adds 676 tokens to every session, about $0.0034 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.
Other instructions, from other repositories
agent-starter-kit AGENTS.md
Instructions for ntorga/agent-starter-kit, covering agents.md, honesty and ambiguity, code shape, function extraction and duplication.
codevira CLAUDE.md
Instructions for sachinshelke/codevira, covering codevira — persistent project memory, when to call which codevira tool, at the start of every session, before modifying any file and before adopting a pattern, library, or naming convention.
gemini-kit GEMINI.md
Instructions for nth5693/gemini-kit, covering gemini-kit: super engineer team, role & responsibilities, workflows, team members and workflow.
hermes-model-auto-switch AGENTS.md
Instructions for rhishi99/hermes-model-auto-switch, covering install, verify, uninstall, guardrails and conventions.
agentic-coding-workflow AGENTS.md
Instructions for abhilash-m96/agentic-coding-workflow, covering agentic coding workflow, rules, step 1 — understand the full scope, step 2 — propose the chunk plan and step 3 — write the finalised plan.
harness-engineering CLAUDE.md
Instructions for jrenaldi79/harness-engineering, covering claude.md, project overview, core features, essential commands and testing.