# XY Labs - Architecture

> Auto-managed by `yarn xy claude-rules`. Do not edit manually.

- Yarn workspaces monorepo; all packages share a single version
- Each package emits declarations with `tsc` and ESM JavaScript with esbuild (output to `dist/`)
- Prefer composition over inheritance; depend on abstractions
- Vitest for testing; React + MUI for frontend; Express for backend
