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/leanprover/lean-beam/agents-mdgit clone --depth 1 https://github.com/leanprover/lean-beamWhat 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 | $0.01599 | $0.01599 |
| Opus 5 | $0.00800 | $0.00800 |
| Sonnet 5 | $0.00320 | $0.00320 |
| Haiku 4.5 | $0.00160 | $0.00160 |
Grade C, and why
lean-beam AGENTS.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 2d 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.
`rm -rf` against repo-local `.beam`, install caches, or user homes as part of normal workflows How it starts
The opening of the file, as written. The whole thing — 160 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md
Purpose
This repository hosts the pre-stable Beam Lean plugin, wrapper, and local broker tooling.
Treat the repo as public but still experimental: prefer conservative, well-tested changes over feature sprawl.
Current public status and limitations live in docs/STATUS.md. Compatibility policy lives in docs/COMPATIBILITY.md. User setup lives in docs/SETUP.md. Exact MCP behavior lives in docs/MCP.md, and exact sync/save/diagnostic behavior lives in docs/SYNC_AND_DIAGNOSTICS.md.
Product Priorities
In order:
- dead-simple public API
- rock-solid stability
- type-safe boundaries
- isolation of each request
- performance
Performance matters, but not at the cost of correctness or stability.
Public API Guardrails
The core public request should remain conceptually:
runAt(pos, "lean text")
Rules:
- no required public mode flag for command vs tactic execution
- backend selection is internal
- keep request and response structures small and typed
- use transport errors for invalid params, stale state, cancellation, and internal faults
- avoid exposing internal execution details unless a concrete client need forces it
Follow-up handle APIs exist, but they are pre-stable extensions around the basic request, not the main story of the project.
Execution Model
Each request should behave like an isolated sandbox:
- never mutate the document's real elaboration state
- never depend on side effects from a previous request
- never leak internal mutable state through the base API
- discard derived execution state unless the request explicitly stores a follow-up handle
Testing Priorities
Tests matter more than cleverness.
Focus on:
- position selection and boundary behavior
- whitespace and comment positions
- proof-vs-command basis selection
- stale snapshot and file-changed behavior
- nested tactic cases
- no state leakage across requests
- cancellation behavior
- handle invalidation when handle behavior is touched
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.
- 2d ago First seen · 160 lines · 1,599 tokens per session scan C f0ef696ea68f
lean-beam AGENTS.md is an instructions file published in the GitHub repository leanprover/lean-beam (24 stars, last pushed 2d ago), licensed Apache-2.0. It adds 1,599 tokens to every session, about $0.0080 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
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
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, 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.
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.