# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
Detailed module docs are loaded automatically when working in subdirectories:

- **`packages/CLAUDE.md`** — Package overview (all packages at a glance)
- **`packages/pen-types/CLAUDE.md`** — Type definitions for PenDocument model
- **`packages/pen-core/CLAUDE.md`** — Document tree ops, layout engine, variables, boolean ops
- **`packages/pen-engine/CLAUDE.md`** — Headless design engine (document, selection, history, viewport)
- **`packages/pen-react/CLAUDE.md`** — React UI SDK (provider, hooks, panels, canvas)
- **`packages/pen-figma/CLAUDE.md`** — Figma .fig file parser and converter
- **`packages/pen-renderer/CLAUDE.md`** — Standalone CanvasKit/Skia renderer
- **`packages/pen-mcp/CLAUDE.md`** — MCP server (tools, routes, document manager)
- **`packages/pen-ai-skills/CLAUDE.md`** — AI prompt skill engine (phase-driven loading)
- **`packages/pen-sdk/CLAUDE.md`** — Umbrella SDK (re-exports all packages)
- **`packages/agent-native/CLAUDE.md`** — Zig agent runtime (NAPI addon)
- **`apps/web/CLAUDE.md`** — Web app (canvas engine, stores, components, AI services)
- **`apps/desktop/CLAUDE.md`** — Electron desktop app (IPC, file association, auto-updater)
- **`apps/cli/CLAUDE.md`** — CLI tool (`op` commands, input methods, connection)

## Commands

- **Dev server:** `bun --bun run dev` (runs on port 3000)
- **Build:** `bun --bun run build`
- **Preview production build:** `bun --bun run preview`
- **Run all tests:** `bun --bun run test` (Vitest)
- **Run a single test:** `bun --bun vitest run path/to/test.ts`
- **Type check:** `npx tsc --noEmit`
- **Lint:** `bun run lint` (oxlint)
- **Format:** `bun run format` (oxfmt)
- **Install dependencies:** `bun install`
- **Bump version:** `bun run bump <version>` (syncs all package.json files)
- **Electron dev:** `bun run electron:dev` (starts Vite + Electron together)
- **Electron compile:** `bun run electron:compile` (esbuild electron/ to out/desktop/)
- **Electron build:** `bun run electron:build` (full web build + compile + electron-builder package)
- **CLI compile:** `bun run cli:compile` (esbuild CLI to apps/cli/dist/)
- **CLI dev:** `bun run cli:dev` (run CLI from source via Bun)
- **MCP dev:** `bun run mcp:dev` (run MCP server from source)
- **Publish beta:** `bun run publish:beta [N]` (publish all npm packages with beta tag)

## Architecture

OpenPencil is an open-source vector design tool (alternative to Pencil.dev) with a Design-as-Code philosophy. Organized as a **Bun monorepo** with workspaces:

```text
openpencil/
├── apps/
│   ├── web/           TanStack Start full-stack React app (Vite + Nitro)
│   ├── desktop/       Electron desktop app (macOS, Windows, Linux)
│   └── cli/           CLI tool — control the design tool from the terminal
├── packages/
│   ├── pen-types/     Type definitions for PenDocument model
│   ├── pen-core/      Document tree ops, layout engine, variables, boolean ops, clone utilities
│   ├── pen-engine/    Headless design engine — framework-free document, selection, history, viewport
│   ├── pen-react/     React UI SDK — DesignProvider, DesignCanvas, hooks, panels, toolbar
│   ├── pen-codegen/   Multi-platform code generators
│   ├── pen-figma/     Figma .fig file parser and converter
│   ├── pen-renderer/  Standalone CanvasKit/Skia renderer
│   ├── pen-mcp/       MCP server — tools, routes, document manager for external CLI integration
│   ├── pen-sdk/       Umbrella SDK (re-exports all packages)
│   ├── pen-ai-skills/ AI prompt skill engine (phase-driven prompt loading + design memory)
│   └── agent-native/  Native AI agent runtime (Zig NAPI, multi-provider, agent teams)
├── scripts/           Build and publish scripts
└── .githooks/         Pre-commit version sync from branch name
```

**Key technologies:** React 19, CanvasKit/Skia WASM (canvas engine), Paper.js (boolean path operations), Zustand v5 (state management), TanStack Router (file-based routing), Tailwind CSS v4, shadcn/ui (UI primitives), Vite 7, Nitro (server), Electron 35 (desktop), Vercel AI SDK v6 (agent framework), i18next (15 locales), TypeScript (strict mode), oxlint/oxfmt (linting & formatting).

### Data Flow

```text
React Components (Toolbar, LayerPanel, PropertyPanel)
        │ Zustand hooks
        ▼
┌─────────────────┐    ┌───────────────────┐
│  canvas-store   │    │  document-store   │ ← single source of truth
│  (UI state:     │    │  (PenDocument)    │
│   tool/selection │    │  CRUD / tree ops  │
│   /viewport)    │    │                   │
└────────┬────────┘    └────────┬──────────┘
         │                      │
         ▼                      ▼
   CanvasKit/Skia        canvas-sync-lock
   (GPU-accelerated      (prevents circular sync)
    WASM renderer)
```

- **document-store** is the single source of truth. CanvasKit only renders.
- User edits on canvas → SkiaEngine events → update document-store
- User edits in panels → update document-store → SkiaEngine `syncFromDocument()` re-renders
- `canvas-sync-lock.ts` prevents circular updates when canvas events write to the store

### Multi-Page Architecture

```text
PenDocument
  ├── pages?: PenPage[]   (id, name, children)
  └── children: PenNode[] (default/single-page fallback)
```

### Design Variables Architecture

- **`$variable` references are preserved** in the document store (e.g. `$color-1` in fill color)
- `resolveNodeForCanvas()` resolves `$refs` on-the-fly before CanvasKit rendering
- Code generators output `var(--name)` for `$ref` values
- Multiple theme axes supported (e.g. Theme-1 with Light/Dark, Theme-2 with Compact/Comfortable)

### MCP Layered Design Workflow

External LLMs (Claude Code, Codex, Gemini CLI, etc.) can generate designs via MCP:

- **Single-shot**: `batch_design` or `insert_node` — one call
- **Layered**: `design_skeleton` → `design_content` × N → `design_refine` — phased generation with focused context
- **Segmented prompts**: `get_design_prompt(section=...)` loads focused subsets (schema, layout, roles, icons, etc.)

### Path Aliases

`@/*` maps to `./src/*` (configured in `apps/web/tsconfig.json` and `apps/web/vite.config.ts`).

### Styling

Tailwind CSS v4 imported via `apps/web/src/styles.css`. UI primitives from shadcn/ui. Icons from `lucide-react`.

### CLI (`apps/cli/`)

The `op` command-line tool controls the desktop app or web server from the terminal. Arguments that accept JSON or DSL support three input methods: inline string, `@filepath` (read from file), or `-` (read from stdin).

- **App control:** `op start [--desktop|--web]`, `op stop`, `op status`
- **Design:** `op design <dsl|@file|->` — batch design DSL operations
- **Document:** `op open`, `op save`, `op get`, `op selection`
- **Nodes:** `op insert`, `op update`, `op delete`, `op move`, `op copy`, `op replace`
- **Export:** `op export <react|html|vue|svelte|flutter|swiftui|compose|rn|css>`
- **Cross-platform:** macOS, Windows (NSIS/portable), Linux (AppImage/deb/snap/flatpak)

### CI / CD

- **`.github/workflows/ci.yml`** — Push/PR on `main` and `v*` branches: type check, tests, web build
- **`.github/workflows/build-electron.yml`** — Tag push (`v*`) or manual: builds Electron for all platforms, creates draft GitHub Release
- **`.github/workflows/publish-cli.yml`** — Tag push (`v*`) or manual: publishes all `@zseven-w/*` npm packages in topological order
- **`.github/workflows/docker.yml`** — Docker image build and push

### Version Sync

- **Pre-commit hook** (`.githooks/pre-commit`): extracts version from branch name (e.g. `v0.5.0` → `0.5.0`) and syncs to all `package.json` files
- **Manual bump:** `bun run bump <version>` to set a specific version across all workspaces
- Requires `git config core.hooksPath .githooks` (one-time setup per clone)

## Code Style

- Single files must not exceed 800 lines. Split into smaller modules when they grow beyond this limit.
- One component per file, each with a single responsibility.
- `.ts` and `.tsx` files use kebab-case naming, e.g. `canvas-store.ts`, `use-keyboard-shortcuts.ts`.
- UI components must use shadcn/ui design tokens (`bg-card`, `text-foreground`, `border-border`, etc.). No hardcoded Tailwind colors like `gray-*`, `blue-*`.
- Toolbar button active state uses `isActive` conditional className (`bg-primary text-primary-foreground`), not Radix Toggle's `data-[state=on]:` selector (has twMerge conflicts).

## Git Commit Convention

Use [Conventional Commits](https://www.conventionalcommits.org/) format: `<type>(<scope>): <subject>`

**Types:** `feat`, `fix`, `refactor`, `perf`, `style`, `docs`, `test`, `chore`

**Scopes:** `editor`, `canvas`, `panels`, `history`, `ai`, `codegen`, `store`, `types`, `variables`, `figma`, `mcp`, `electron`, `renderer`, `sdk`, `cli`, `agent`, `i18n`

**Rules:** Subject in English, lowercase start, no period, imperative mood. Body is optional; explain **why** not what. One commit per change.

## License

MIT License. See [LICENSE](./LICENSE) for details.
