Borrowing it
Nothing to install: this file belongs to jasonkneen/agent-skills. 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/jasonkneen/agent-skills/main/CLAUDE.mdgit clone --depth 1 https://github.com/jasonkneen/agent-skillsWrote 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/jasonkneen/agent-skills/claude-md)<a href="https://agentmods.dev/instructions/jasonkneen/agent-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/jasonkneen/agent-skills/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/jasonkneen/agent-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/jasonkneen/agent-skills/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 | $0.02764 | $0.02764 |
| Opus 5 | $0.01382 | $0.01382 |
| Sonnet 5 | $0.00553 | $0.00553 |
| Haiku 4.5 | $0.00276 | $0.00276 |
Grade B, and why
agent-skills 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 9d 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.
Reads agent configuration directoriesmediumAgent snooping
.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.
7. Test by adding to `~/.claude/settings.json` mcpServers config How it starts
The opening of the file, as written. The whole thing — 319 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.
Build Commands
- Build all packages:
pnpm build - Build specific package:
cd packages/<name> && pnpm build - Dev mode (watch):
pnpm devorcd packages/<name> && pnpm dev - Type check:
pnpm typecheck - Lint:
pnpm lint - Test:
pnpm test - Clean:
pnpm clean
Project Structure
This is a pnpm monorepo containing Claude Code extensions:
claude-skills/
├── packages/ # MCP servers (TypeScript, builds to dist/)
│ ├── mcp-github-issues/
│ └── mcp-debug-cycle/
├── skills/ # Agent Skills (SKILL.md format)
│ └── code-review/
└── hooks/ # Claude Code hooks (Node.js scripts)
├── cost-monitor/
├── notify-complete/
└── tdd-enforcement/
Architecture
MCP Servers (packages/)
TypeScript packages following MCP SDK patterns:
- Entry:
src/index.tsexportsServerfrom@modelcontextprotocol/sdk/server/index.js - Tools:
src/tools/*.tsexportTooldefinitions and implementation functions - Utils:
src/utils/*.tsfor shared logic (e.g.,gh-cli.tswraps GitHub CLI) - Build: TypeScript compiles
src/→dist/, usingtsconfig.base.json+ package-leveltsconfig.json - Execution:
dist/index.jsis the MCP server entry point (runs vianode)
Tool implementations follow this pattern:
export const toolName: Tool = {
name: "mcp_tool_name",
description: "...",
inputSchema: { /* Zod or JSON Schema */ }
}
export async function toolName(args: ArgsType): Promise<ToolResponse> {
// Implementation
}
Agent Skills (skills/)
Agent Skills Specification (agentskills.io) compliant format:
- Structure: Each skill is a directory with
SKILL.mdas the manifest - Frontmatter: YAML with required fields
name(lowercase-hyphen only) anddescription - Content: Markdown body with skill instructions, using XML-style tags for structure:
<essential_principles>- Core philosophy and rules<intake>- User-facing prompt for skill invocation<routing>- Pattern matching to workflow files<reference_index>- Links to reference docs<workflows_index>- Available workflow files
- Supporting files:
references/- On-demand docs (e.g., checklists, common issues)workflows/- Step-by-step procedures (e.g., review-diff.md)scripts/- Executable code (if needed)assets/- Templates, data files
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.
- 9d ago First seen · 319 lines · 2,764 tokens per session scan B b577ede04583
agent-skills CLAUDE.md is an instructions file published in the GitHub repository jasonkneen/agent-skills (20 stars, last pushed 8mo ago), licensed MIT. It adds 2,764 tokens to every session, about $0.0138 per session on Opus 5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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.
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.
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).
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).
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.
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.