moon is a Rust-based build system and repository management tool for web projects, including monorepos, where multiple related packages live in one repository. It coordinates projects and tasks, standardizes language and package-manager versions, and reduces duplicated scripts. The catalogue skills and instructions support working with moon-managed repositories.
Borrowing it
Nothing to install: this file belongs to moonrepo/moon. 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/moonrepo/moon/master/AGENTS.mdgit clone --depth 1 https://github.com/moonrepo/moonWrote 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/moonrepo/moon/agents-md)<a href="https://agentmods.dev/instructions/moonrepo/moon/agents-md"><img src="https://agentmods.dev/badge/instructions/moonrepo/moon/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.
<a href="https://agentmods.dev/instructions/moonrepo/moon/agents-md"><img src="https://agentmods.dev/badge/instructions/moonrepo/moon/agents-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 | $0.01273 | $0.01273 |
| Opus 5.5 | $0.00509 | $0.00509 |
| Sonnet 5.5 | $0.00255 | $0.00255 |
| Haiku 4.5 | $0.00127 | $0.00127 |
Grade A, and why
moon 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 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.
How it starts
The opening of the file, as written. The whole thing — 104 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md
Guidance for AI coding agents working in the moon repository. moon is a repository management,
organization, orchestration, and notification tool for the web ecosystem. The core is written in
Rust and ships alongside a set of @moonrepo/* npm packages. moon is built with moon, so every
npm package is itself a moon project.
Repository layout
| Path | Contents |
|---|---|
.moon/ |
moon workspace config (workspace.yml, toolchains.yml, tasks/) |
crates/* |
Rust crates; crates/cli is the default binary |
packages/* |
TypeScript npm packages; @moonrepo/* scope |
wasm/* |
Test WASM plugins built for wasm32-wasip1 |
website/ |
Documentation site (also a moon project) |
Prerequisites
- Rust >= 1.97 (pinned in
rust-toolchain.toml, edition 2024) - Cargo — Rust toolchain
- Protocol Buffers compiler —
protoconPATH(or via thePROTOCenv var), required to buildcrates/daemon-proto - Node.js >= 22.18
- Yarn >= 4
- Just — Rust task runner
- Vite+ — JavaScript toolchain
- Git >= 2.28
First-time setup:
just init # installs cargo-nextest, cargo-insta, cargo-llvm-cov, etc.
just build # builds the `moon` binary (required for the JS workflow)
vp install # installs node modules
Rust workflow
Use just for all Rust tasks. Always run format, lint, and test before finishing a change.
just build- Builds all Rust crates.just build-wasm- Builds test related WASM plugins (required for tests).just check- Checks all Rust crates without producing binaries.just format- Formats all Rust code withrustfmt.just lint- Lints all Rust code withclippy(treats warnings as errors).just test- Runs all Rust tests withcargo nextest.just test <filter>- Runs all Rust tests matching the filter.just test-package- Runs tests for a single package/crate by name.just cov- Runs Rust tests with LLVM coverage (slow).
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 Changed · +2 lines · +47 tokens per session 5ec2cd778b02
- 2mo ago First seen · 102 lines · 1,226 tokens per session scan A 8b4bba7a3f92
moon AGENTS.md is an instructions file published in the GitHub repository moonrepo/moon (4,171 stars, last pushed today), licensed MIT. It adds 1,273 tokens to every session, about $0.0051 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 2026-08-30.
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).
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.