cargo-usage-rules

A cargo subcommand that aggregates usage-rules.md files from your Rust project dependencies into a single file for AI agent consumption.

Inspired by the Elixir ash-project/usage_rules. They have some pretty compelling evidence of it's efficacy.

Installation

cargo install cargo-usage-rules

Or with binstall:

cargo binstall cargo-usage-rules

Or from source:

cargo install --git https://github.com/pallas-jp/cargo_usage_rules

Usage

Sync all dependencies

cargo usage-rules sync --all

List available packages with usage rules

cargo usage-rules list

Sync with custom output file

cargo usage-rules sync --all --output AI.md

Inline specific packages

cargo usage-rules sync --inline serde,tokio,clap

Exclude specific packages

cargo usage-rules sync --all --remove old-crate,deprecated-dep

Create separate files with links (folder mode)

# Markdown links (default)
cargo usage-rules sync --all --link-to-folder usage-rules

# Claude @ links
cargo usage-rules sync --all --link-to-folder usage-rules --link-style at

Usage Reccomendations

In my experience using the inspiring project, linked mode works great and doesn't pollute the context window, so syncing all with the default linked mode.

If you have few dependencies then inline might be more performant for you, but YMMV.

How It Works

cargo-usage-rules scans your Rust project dependencies (from crates.io, git, local paths, etc) for:

• usage-rules.md files (main usage guidance)

It then aggregates these files into a single output file (default: Agents.md) with clear package boundaries marked by HTML comments.

This project also has some general rust guidance (see the base file) inspired by various sources (see acknowledgements).

Creating Usage Rules for Your Crate

To make your crate discoverable by cargo-usage-rules, add a usage-rules.md file to your crate's root directory:

# My Awesome Crate

## Quick Start

[Your usage guidance for AI agents here]

## Common Patterns

[Examples and best practices]

## Common Mistakes

[What to avoid]