Borrowing it
Nothing to install: this file belongs to end1989/repos-expert. 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/end1989/repos-expert/main/CLAUDE.mdgit clone --depth 1 https://github.com/end1989/repos-expertWrote 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/end1989/repos-expert/claude-md)<a href="https://agentmods.dev/instructions/end1989/repos-expert/claude-md"><img src="https://agentmods.dev/badge/instructions/end1989/repos-expert/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 5.1 | $0.00964 | $0.00964 |
| Opus 5 | $0.00482 | $0.00482 |
| Sonnet 5 | $0.00193 | $0.00193 |
| Haiku 4.5 | $0.00096 | $0.00096 |
Grade A, and why
repos-expert CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 78 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Working on repos-expert
This tool turns a folder of code repositories into a knowledge base an AI assistant can answer from. ARCHITECTURE.md explains the design; this file is about changing it safely.
Ground rules
TDD. Write the failing test first, watch it fail for the right reason, then implement. Tests build real git repositories in temp directories and inject fake agent runners — no network, no model calls, no mocking of git.
Never write to stdout in the MCP path. stdout is the protocol. A stray console.log
in anything reachable from expert mcp corrupts the stream and breaks the client, usually
with a confusing error. Diagnostics go to stderr.
Every subprocess call uses execFile with an argument array. No shell strings, ever.
Repo names are validated against /^[A-Za-z0-9._-]+$/ before they reach a path or a
command line — that check is what stops ../ from becoming a file read outside the folder.
URLs in repos.txt go through a transport allowlist (https, http, ssh, git, file,
and the user@host:path form). It is an allowlist rather than a denylist because git's
ext:: transport runs a shell command — a URL pasted from a chat window must not reach
it. The derived folder name goes through the same name check as everything else.
Caps are load-bearing. 100 search matches, 2,000 lines / 200 KB per file read. They exist because results land in someone's context window, not for speed. Don't relax them without a reason that accounts for that.
Failure is per-repo. One repo failing to curate is collected and reported; the batch continues. A failed GitHub sync does not stop curation of what is already on disk. An empty folder produces instructions, not an error. Preserve this — it is the difference between a tool that works in a degraded environment and one that doesn't.
The curator is a model, and models are wrong sometimes
The knowledge docs are written by an agent. Two consequences the code must keep honoring:
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.
- 7d ago First seen · 78 lines · 964 tokens per session scan A c1373f809677
repos-expert CLAUDE.md is an instructions file published in the GitHub repository end1989/repos-expert (0 stars, last pushed 4d ago), licensed MIT. It adds 964 tokens to every session, about $0.0048 per session on Opus 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.
Other instructions, from other repositories
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).
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.
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.
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).
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.