What is lean-md AGENTS.md?

Repository instructions for developing lean-md, a Rust tool that renders extended Markdown and sends code-intelligence requests through command-line or MCP connections. MCP is a protocol for connecting an agent to external tools, while code intelligence means searching and navigating source code using its structure.

Use these instructions when modifying lean-md, especially for cached code searches, anchored file patches, symbol navigation, refactoring, and shell commands through lean-ctx.

They define how to read, search, run commands, and edit this repository while conserving context and keeping tool usage consistent. They also describe how lean-md connects to lean-ctx without directly depending on it.

How dasTholo/lean-md configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to dasTholo/lean-md. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/dasTholo/lean-md/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/dasTholo/lean-md

Made for: Codex, OpenCode.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/dastholo/lean-md/agents-md/github.svg)](https://agentmods.dev/instructions/dastholo/lean-md/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/dastholo/lean-md/agents-md"><img src="https://agentmods.dev/badge/instructions/dastholo/lean-md/agents-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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/dastholo/lean-md/agents-md"><img src="https://agentmods.dev/badge/instructions/dastholo/lean-md/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,503 This file is loaded in full into every session.

When invoked 1,503 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

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	$0.01503	$0.01503
Opus 5.5	$0.00601	$0.00601
Sonnet 5.5	$0.00301	$0.00301
Haiku 4.5	$0.00150	$0.00150

Measured 2mo ago against content hash c2adf4cd2642, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

lean-md AGENTS.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 2mo 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.

AGENTS.md · 119 lines

How it starts

The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.

lean-md — Macro/Directive Markdown Renderer

lean-md is a standalone crate (lib lean_md + bin lean-md) distributed as a lean-ctx addon. Its render core (rushdown + evalexpr) runs in-process and needs zero lean-ctx. Every code-intel directive is outbound over the MCP/CLI wire via backend::CodeIntelBackend (CLI default, MCP opt-in) — lean-md holds no lean_ctx crate dependency (only lean-ctx-client, behind the mcp feature).

Integration Mode: Hybrid (for developing THIS repo)

When working on lean-md itself, prefer lean-ctx tooling for token savings:

Reads/Search → MCP tools (ctx_read, ctx_search) for caching + compression
Shell commands → lean-ctx -c "…" via CLI (preferred) or ctx_shell via MCP
File editing → anchored loop ctx_read(mode=anchored) → ctx_patch (default, patch by LINE:HASH anchor); ctx_edit only tiny-span/replace-all; symbol nav/refactor/reformat via ctx_refactor; symbol body by name via ctx_search action=symbol

MCP tools

Tool	Purpose
`ctx_read(path, mode)`	Cached, compressed file reads (10 modes)
`ctx_search(pattern, path)`	Token-efficient code search
`ctx_shell(command)`	Compressed shell output (alternative to CLI)
`ctx_patch(path, anchor)`	Anchored edit (default): patch by LINE:HASH from `ctx_read(mode=anchored)`
`ctx_edit(path, old, new)`	str_replace fallback — tiny-span / replace-all
`ctx_refactor`	LSP/PSI symbol nav, refactor engine, `action=reformat` (pre-commit)

CLI commands (optimized shell, lower overhead)

lean-ctx -c "git status"     # compressed shell output
lean-ctx -c "cargo nextest run"  # compressed test output
lean-ctx ls src/              # directory map

Read the full file on GitHub · 119 lines

Changes

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.

2mo ago First seen · 119 lines · 1,503 tokens per session scan A c2adf4cd2642

Subscribe to this mod's changes

lean-md AGENTS.md is an instructions file published in the GitHub repository dasTholo/lean-md (5 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 1,503 tokens to every session, about $0.0060 per session on Opus 5.5. 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.

Writing and docs

lean-md AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
lean-md AGENTS.mddasTholo/lean-md	Instructions file	5	1mo ago	Apache-2.0	A	1,503	Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	today	MIT	A	7,461	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	5,516	GitHub Copilot
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	today	MIT	A	4,680	Codex, OpenCode
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	275k	3d ago	MIT	A	4,313	Codex, OpenCode

lean-md: Instructions file for Codex