RepoBrain is a repository knowledge engine that lets coding agents ask grounded questions about a codebase and receive answers linked to source files and lines. It is for developers using Claude Code, Cursor, Codex, Windsurf, and other AI coding tools. Catalogue add-ons extend its commands, instructions, skills, rules, plugin, and hook workflows.
Borrowing it
Nothing to install: this file belongs to study8677/repobrain. 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/study8677/repobrain/main/CLAUDE.mdgit clone --depth 1 https://github.com/study8677/repobrainWrote 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/study8677/repobrain/claude-md)<a href="https://agentmods.dev/instructions/study8677/repobrain/claude-md"><img src="https://agentmods.dev/badge/instructions/study8677/repobrain/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/study8677/repobrain/claude-md"><img src="https://agentmods.dev/badge/instructions/study8677/repobrain/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 | $0.00218 | $0.00218 |
| Opus 5.5 | $0.00087 | $0.00087 |
| Sonnet 5.5 | $0.00044 | $0.00044 |
| Haiku 4.5 | $0.00022 | $0.00022 |
Grade A, and why
repobrain 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 1mo 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.
This is a copy
89% identical to 1code AGENTS.md — 12 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
What it actually says
CLAUDE.md
Claude Code bootstrap file.
Primary behavior rules live in AGENTS.md.
OpenSpec Instructions
These instructions are for AI assistants working in this project.
Always open @/openspec/AGENTS.md when the request:
- Mentions planning or proposals (words like proposal, spec, change, plan)
- Introduces new capabilities, breaking changes, architecture shifts, or big performance/security work
- Sounds ambiguous and you need the authoritative spec before coding
Use @/openspec/AGENTS.md to learn:
- How to create and apply change proposals
- Spec format and conventions
- Project structure and guidelines
Keep this managed block so 'openspec update' can refresh the instructions.
Before acting:
- Read
AGENTS.md. - For spec or proposal work, follow
openspec/AGENTS.md. - Load project context from
CONTEXT.md,.repobrain/, andmission.mdonly as needed.
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.
- 1mo ago First seen · 30 lines · 218 tokens per session scan A e1e5a13b72a2
repobrain CLAUDE.md is an instructions file published in the GitHub repository study8677/repobrain (1,345 stars, last pushed 2d ago), licensed MIT. It adds 218 tokens to every session, about $0.0009 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 89% identical to 1code AGENTS.md, differing in 12 lines, and is treated as a copy.
Other instructions, from other repositories
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.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
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.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).