CLAUDE.md

1# CLAUDE.md
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3## Project Structure
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5Excalidraw is a **monorepo** with a clear separation between the core library and the application:
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7- **`packages/excalidraw/`** - Main React component library published to npm as `@excalidraw/excalidraw`
8- **`excalidraw-app/`** - Full-featured web application (excalidraw.com) that uses the library
9- **`packages/`** - Core packages: `@excalidraw/common`, `@excalidraw/element`, `@excalidraw/math`, `@excalidraw/utils`
10- **`examples/`** - Integration examples (NextJS, browser script)
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12## Development Workflow
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141. **Package Development**: Work in `packages/*` for editor features
152. **App Development**: Work in `excalidraw-app/` for app-specific features
163. **Testing**: Always run `yarn test:update` before committing
174. **Type Safety**: Use `yarn test:typecheck` to verify TypeScript
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19## Development Commands
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21```bash
22yarn test:typecheck  # TypeScript type checking
23yarn test:update     # Run all tests (with snapshot updates)
24yarn fix             # Auto-fix formatting and linting issues
25```
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27## Architecture Notes
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29### Package System
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31- Uses Yarn workspaces for monorepo management
32- Internal packages use path aliases (see `vitest.config.mts`)
33- Build system uses esbuild for packages, Vite for the app
34- TypeScript throughout with strict configuration
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