Borrowing it
Nothing to install: this file belongs to existential-birds/beagle. 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/existential-birds/beagle/main/CLAUDE.mdgit clone --depth 1 https://github.com/existential-birds/beagleWrote 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/existential-birds/beagle/claude-md)<a href="https://agentmods.dev/instructions/existential-birds/beagle/claude-md"><img src="https://agentmods.dev/badge/instructions/existential-birds/beagle/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/existential-birds/beagle/claude-md"><img src="https://agentmods.dev/badge/instructions/existential-birds/beagle/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 | $0.02129 | $0.02129 |
| Opus 5.5 | $0.00852 | $0.00852 |
| Sonnet 5.5 | $0.00426 | $0.00426 |
| Haiku 4.5 | $0.00213 | $0.00213 |
Grade B, and why
beagle 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 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.
Reads agent configuration directoriesmediumAgent snooping
.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.
# In Claude Code settings (~/.claude/settings.json) This is a copy
88% identical to beagle AGENTS.md — 28 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.
How it starts
The opening of the file, as written. The whole thing — 130 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.
What This Is
Beagle is a Claude Code plugin marketplace providing framework-aware code review skills and verification workflows for pre-push reviews and GitHub bot feedback handling. It contains 10 focused plugins with 132 skills.
Marketplace Architecture
beagle/
├── .claude-plugin/
│ └── marketplace.json # Marketplace manifest (10 plugins)
└── plugins/
├── beagle-core/ # Shared workflows, verification, git workflows, skill tooling (19 skills)
├── beagle-python/ # Python, FastAPI, SQLAlchemy, PostgreSQL, pytest (7 skills)
├── beagle-go/ # Go, BubbleTea, Wish SSH, Prometheus (13 skills)
├── beagle-elixir/ # Elixir, Phoenix, LiveView, ExUnit, ExDoc (11 skills)
├── beagle-ios/ # Swift, SwiftUI, SwiftData, iOS frameworks (16 skills)
├── beagle-react/ # React, React Flow, shadcn/ui, Tailwind, Vitest, Remix v2 (28 skills)
├── beagle-rust/ # Rust, tokio, axum, sqlx, serde (12 skills)
├── beagle-ai/ # Pydantic AI, LangGraph, DeepAgents, Vercel AI SDK (deprecated)
├── beagle-docs/ # Documentation quality, AI writing detection (10 skills)
├── beagle-analysis/ # Brainstorming, ADRs, strategy, LLM-as-judge, spec resolution, PRFAQ filter, TDD plan writing (14 skills)
└── beagle-testing/ # Test plan generation and execution (2 skills)
Each active plugin is a directory under plugins/ with its own README.md and skills/ directory. The marketplace manifest at .claude-plugin/marketplace.json is the only plugin manifest; individual plugin directories do not have plugin.json files.
Local Development
Test the marketplace during development:
# In Claude Code settings (~/.claude/settings.json)
{
"plugins": ["/path/to/your/beagle"]
}
Restart Claude Code after changes to reload. Skills are discovered from plugin skills/ directories and trigger keywords in skill frontmatter. Codex support files are in .codex/INSTALL.md and docs/README.codex.md.
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 · 130 lines · 2,129 tokens per session scan B 039d34845a20
beagle CLAUDE.md is an instructions file published in the GitHub repository existential-birds/beagle (85 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 2,129 tokens to every session, about $0.0085 per session on Opus 5.5. A static security scan graded it B with 1 finding (reads agent configuration directories). It is 88% identical to beagle AGENTS.md, differing in 28 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.
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).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.