# Unity Beaver

> Lets AI coding agents compile-check C# in the running Unity Editor. After editing `.cs` files, the agent runs `unity-beaver check`; Unity recompiles and the agent gets back real compiler errors with `file:line:column`, so it can fix its own mistakes.

Source: https://github.com/ruizhengu/unity-beaver
Author: Ruizhen Gu

## Set up for the user

If you are an agent asked to set up Unity Beaver, do the steps below in order. Tell the user what each command does before you run it.

1. Install the CLI. It needs Node.js 18 or newer (`node --version`).
   `npm install -g unity-beaver`
2. Go to the Unity project folder (it has `Assets/` and `ProjectSettings/`). Preview, then apply:
   `unity-beaver init --dry-run`
   `unity-beaver init`
   This adds the Unity package to `Packages/manifest.json` and writes compile-check instructions to `AGENTS.md` (and `CLAUDE.md`).
3. Ask the user to switch to the Unity Editor so it imports the package. Then run:
   `unity-beaver doctor`
   Setup is done when it ends with "All set." Otherwise relay the `→` hints to the user.
4. Optional, for Claude Code, Codex, Cursor and other agents that support skills:
   `npx skills add ruizhengu/unity-beaver -g -y`
   Or in Claude Code: `/plugin marketplace add ruizhengu/unity-beaver`, then `/plugin install unity-beaver@unity-beaver`.

## Using it

After you create, edit, move, or delete `.cs` files, run `unity-beaver check` from the project folder:

- Exit `0`: Unity compiled the project. Warnings don't block.
- Exit `1`: fix each error at its `file:line:column`, then run the check again until it exits `0`.
- Exit `2`: Unity couldn't be reached. Run `unity-beaver doctor`, tell the user what it reports, and stop retrying.

`unity-beaver check --json` prints `errors` and `warnings` with `file`, `line`, `column`, `code`, and `message`.