The world's first open-source AI-native vector design tool and the first to feature concurrent Agent Teams. Design-as-Code. Turn prompts into UI directly on the live canvas. A modern alternative to Pencil.
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Kayshen Xu 3caaa495bb
V0.5.2 (#82)
* feat(ai): scaffold pen-ai-skills package

* feat(ai): add pen-ai-skills core types

* feat(ai): add Vite plugin for skill file compilation

* feat(ai): add budget module with token estimation and category-priority trimming

* feat(ai): add skill loader with phase filtering and test injection

* feat(ai): add skill resolver with phase filter, intent match, and dynamic injection

* feat(ai): migrate all prompt content to skill files

Extract prompt content from 7 TypeScript source files into 27 Markdown
skill files with proper frontmatter. Each file contains phase, trigger,
priority, budget, and category metadata for the skill resolution engine.

Planning: decomposition, design-type
Generation: jsonl-format, jsonl-format-simplified, schema, layout,
  text-rules, overflow, style-defaults, variables, design-system,
  design-code, design-md
Validation: vision-feedback
Maintenance: local-edit, incremental-add, style-consistency
Domains: landing-page, dashboard, mobile-app, form-ui, cjk-typography
Knowledge: role-definitions, design-principles, icon-catalog,
  copywriting, examples

* feat(ai): add document context memory module

* feat(ai): add generation history memory module

* feat(ai): wire memory loading into skill resolver

Add memory field to ResolveOptions and load documentContext/generationHistory
into AgentContext with per-phase limits (planning:5, maintenance:3, others:0).
Export memory utility functions from package index.

* refactor(ai): use resolveSkills('planning') in orchestrator

Replace ORCHESTRATOR_PROMPT import with resolveSkills() from pen-ai-skills.
The planning phase system prompt is now resolved dynamically from skill
files instead of a static constant.

* refactor(ai): use resolveSkills('generation') in sub-agent

Replace SUB_AGENT_PROMPT + designPrinciples concatenation with
resolveSkills() from pen-ai-skills. The generation phase system prompt
is now resolved dynamically with flag-based skill filtering for
variables and design.md context.

* refactor(ai): use resolveSkills('validation') in design validation

Replace the 70-line inline VALIDATION_SYSTEM_PROMPT constant with a
lazy resolver function that loads the validation prompt from pen-ai-skills
skill files at call time.

* refactor(mcp): use skill registry for design prompt sections

* refactor(ai): remove old prompt files replaced by pen-ai-skills

Delete prompt files whose content has been migrated to the
pen-ai-skills package:
- ai-prompt-sections.ts (section registry, triggers, builders)
- orchestrator-prompts.ts (orchestrator + sub-agent prompts)
- design-system-prompts.ts (design token generation prompt)
- design-code-prompts.ts (HTML/CSS code-gen prompt)
- design-principles/ directory (5 principle files + index)

Consolidate role-definitions/ 8 sub-files into index.ts
(registerRole calls are runtime behavior, must be preserved).

Move buildDesignMdStylePolicy into ai-prompts.ts. Strip migrated
constants (PEN_NODE_SCHEMA, DESIGN_EXAMPLES, ADAPTIVE_STYLE_POLICY,
CHAT_SYSTEM_PROMPT, DESIGN_GENERATOR_PROMPT, etc.) from ai-prompts.ts.

Add pen-ai-skills alias to mcp:compile esbuild script.

* docs: add pen-ai-skills to architecture documentation

* fix(mcp): use h3 v2 createEventStream API for SSE endpoint

event.node.res was removed in h3 v2. Migrate to createEventStream
which handles SSE headers, streaming, and cleanup automatically.

* chore: update package versions and add pen-ai-skills to Dockerfile

- Bump version for multiple packages to 0.5.2, including pen-ai-skills, pen-codegen, pen-core, pen-figma, pen-renderer, pen-sdk, and pen-types.
- Add pen-ai-skills package to Dockerfile for inclusion in the build process.
- Update TypeScript configuration to ensure proper file inclusion.
- Modify GitHub Actions workflow to trigger on version tags.
- Enhance AI-related functionality by integrating resolveAgentModel for dynamic model resolution in chat and generation APIs.

* refactor: clean up unused imports and improve dynamic content handling

- Removed unused imports from various files, including SkillMeta and ResolvedSkill from types.test.ts, and estimateTokens from resolve-skills.ts.
- Updated the dynamic content injection function to use a more concise parameter in the regex replacement callback.

* chore: enhance build and CI workflows with skill generation

- Added a new script to generate the skill registry during post-installation in package.json.
- Updated the GitHub Actions workflows to include steps for compiling the CLI and generating the skill registry, ensuring all necessary components are built and ready for deployment.

---------

Co-authored-by: Fini <fini.yang@gmail.com>
2026-03-24 21:16:28 +08:00
.githooks V0.5.0 (#67) 2026-03-22 09:44:04 +08:00
.github V0.5.2 (#82) 2026-03-24 21:16:28 +08:00
.vscode V0.2.1 (#23) 2026-03-06 21:00:42 +08:00
apps V0.5.2 (#82) 2026-03-24 21:16:28 +08:00
packages V0.5.2 (#82) 2026-03-24 21:16:28 +08:00
screenshot V0.3.0 (#24) 2026-03-08 11:55:35 +08:00
scripts V0.5.2 (#82) 2026-03-24 21:16:28 +08:00
.cta.json Initialize OpenPencil project with essential files and configurations 2026-02-17 21:14:16 +08:00
.dockerignore V0.5.0 (#71) 2026-03-22 10:09:26 +08:00
.gitignore V0.5.0 (#71) 2026-03-22 10:09:26 +08:00
bun.lock V0.5.2 (#82) 2026-03-24 21:16:28 +08:00
CLAUDE.md V0.5.2 (#82) 2026-03-24 21:16:28 +08:00
Dockerfile V0.5.2 (#82) 2026-03-24 21:16:28 +08:00
LICENSE chore: update documentation and add MIT License 2026-02-18 22:35:17 +08:00
package.json V0.5.2 (#82) 2026-03-24 21:16:28 +08:00
README.de.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.es.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.fr.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.hi.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.id.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.ja.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.ko.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.pt.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.ru.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.th.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.tr.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.vi.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.zh-TW.md V0.5.1 (#77) 2026-03-23 21:20:59 +08:00
README.zh.md V0.5.1 (#78) 2026-03-23 22:31:06 +08:00
tsconfig.base.json V0.5.0 (#67) 2026-03-22 09:44:04 +08:00
tsconfig.json V0.5.2 (#82) 2026-03-24 21:16:28 +08:00

OpenPencil

OpenPencil

The world's first open-source AI-native vector design tool.
Concurrent Agent Teams • Design-as-Code • Built-in MCP Server • Multi-model Intelligence

English · 简体中文 · 繁體中文 · 日本語 · 한국어 · Français · Español · Deutsch · Português · Русский · हिन्दी · Türkçe · ไทย · Tiếng Việt · Bahasa Indonesia

Stars License CI Discord


OpenPencil — click to watch demo

Click the image to watch the demo video


Why OpenPencil

🎨 Prompt → Canvas

Describe any UI in natural language. Watch it appear on the infinite canvas in real-time with streaming animation. Modify existing designs by selecting elements and chatting.

🤖 Concurrent Agent Teams

The orchestrator decomposes complex pages into spatial sub-tasks. Multiple AI agents work on different sections simultaneously — hero, features, footer — all streaming in parallel.

🧠 Multi-Model Intelligence

Automatically adapts to each model's capabilities. Claude gets full prompts with thinking; GPT-4o/Gemini disable thinking; smaller models (MiniMax, Qwen, Llama) get simplified prompts for reliable output.

🔌 MCP Server

One-click install into Claude Code, Codex, Gemini, OpenCode, Kiro, or Copilot CLIs. Design from your terminal — read, create, and modify .op files through any MCP-compatible agent.

📦 Design-as-Code

.op files are JSON — human-readable, Git-friendly, diffable. Design variables generate CSS custom properties. Code export to React + Tailwind or HTML + CSS.

🖥️ Runs Everywhere

Web app + native desktop on macOS, Windows, and Linux via Electron. Auto-updates from GitHub Releases. .op file association — double-click to open.

⌨️ CLI — op

Control the design tool from your terminal. op design, op insert, op export — batch design DSL, node manipulation, code export. Pipe in from files or stdin. Works with desktop app or web server.

🎯 Multi-Platform Code Export

Export to React + Tailwind, HTML + CSS, Vue, Svelte, Flutter, SwiftUI, Jetpack Compose, React Native — all from one .op file. Design variables become CSS custom properties.

Quick Start

# Install dependencies
bun install

# Start dev server at http://localhost:3000
bun --bun run dev

Or run as a desktop app:

bun run electron:dev

Prerequisites: Bun >= 1.0 and Node.js >= 18

Docker

Multiple image variants are available — pick the one that fits your needs:

Image Size Includes
openpencil:latest ~226 MB Web app only
openpencil-claude:latest + Claude Code CLI
openpencil-codex:latest + Codex CLI
openpencil-opencode:latest + OpenCode CLI
openpencil-copilot:latest + GitHub Copilot CLI
openpencil-gemini:latest + Gemini CLI
openpencil-full:latest ~1 GB All CLI tools

Run (web only):

docker run -d -p 3000:3000 ghcr.io/zseven-w/openpencil:latest

Run with AI CLI (e.g. Claude Code):

The AI chat relies on Claude CLI OAuth login. Use a Docker volume to persist the login session:

# Step 1 — Login (one-time)
docker volume create openpencil-claude-auth
docker run -it --rm \
  -v openpencil-claude-auth:/root/.claude \
  ghcr.io/zseven-w/openpencil-claude:latest claude login

# Step 2 — Start
docker run -d -p 3000:3000 \
  -v openpencil-claude-auth:/root/.claude \
  ghcr.io/zseven-w/openpencil-claude:latest

Build locally:

# Base (web only)
docker build --target base -t openpencil .

# With a specific CLI
docker build --target with-claude -t openpencil-claude .

# Full (all CLIs)
docker build --target full -t openpencil-full .

AI-Native Design

Prompt to UI

  • Text-to-design — describe a page, get it generated on canvas in real-time with streaming animation
  • Orchestrator — decomposes complex pages into spatial sub-tasks for parallel generation
  • Design modification — select elements, then describe changes in natural language
  • Vision input — attach screenshots or mockups for reference-based design

Multi-Agent Support

Agent Setup
Claude Code No config — uses Claude Agent SDK with local OAuth
Codex CLI Connect in Agent Settings (Cmd+,)
OpenCode Connect in Agent Settings (Cmd+,)
GitHub Copilot copilot login then connect in Agent Settings (Cmd+,)
Gemini CLI Connect in Agent Settings (Cmd+,)

Model Capability Profiles — automatically adapts prompts, thinking mode, and timeouts per model tier. Full-tier models (Claude) get complete prompts; standard-tier (GPT-4o, Gemini, DeepSeek) disable thinking; basic-tier (MiniMax, Qwen, Llama, Mistral) get simplified nested-JSON prompts for maximum reliability.

MCP Server

  • Built-in MCP server — one-click install into Claude Code / Codex / Gemini / OpenCode / Kiro / Copilot CLIs
  • Auto-detects Node.js — if not installed, falls back to HTTP transport and auto-starts the MCP HTTP server
  • Design automation from terminal: read, create, and modify .op files via any MCP-compatible agent
  • Layered design workflowdesign_skeletondesign_contentdesign_refine for higher-fidelity multi-section designs
  • Segmented prompt retrieval — load only the design knowledge you need (schema, layout, roles, icons, planning, etc.)
  • Multi-page support — create, rename, reorder, and duplicate pages via MCP tools

Code Generation

  • React + Tailwind CSS, HTML + CSS, CSS Variables
  • Vue, Svelte, Flutter, SwiftUI, Jetpack Compose, React Native

CLI — op

Install globally and control the design tool from your terminal:

npm install -g @zseven-w/openpencil
op start                     # Launch desktop app
op design @landing.txt       # Batch design from file
op insert '{"type":"RECT"}'  # Insert a node
op export react --out .      # Export to React + Tailwind
op import:figma design.fig   # Import Figma file
cat design.dsl | op design - # Pipe from stdin

Supports three input methods: inline string, @filepath (read from file), or - (read from stdin). Works with desktop app or web dev server. See CLI README for full command reference.

Features

Canvas & Drawing

  • Infinite canvas with pan, zoom, smart alignment guides, and snapping
  • Rectangle, Ellipse, Line, Polygon, Pen (Bezier), Frame, Text
  • Boolean operations — union, subtract, intersect with contextual toolbar
  • Icon picker (Iconify) and image import (PNG/JPEG/SVG/WebP/GIF)
  • Auto-layout — vertical/horizontal with gap, padding, justify, align
  • Multi-page documents with tab navigation

Design System

  • Design variables — color, number, string tokens with $variable references
  • Multi-theme support — multiple axes, each with variants (Light/Dark, Compact/Comfortable)
  • Component system — reusable components with instances and overrides
  • CSS sync — auto-generated custom properties, var(--name) in code output

Figma Import

  • Import .fig files with layout, fills, strokes, effects, text, images, and vectors preserved

Desktop App

  • Native macOS, Windows, and Linux via Electron
  • .op file association — double-click to open, single-instance lock
  • Auto-update from GitHub Releases
  • Native application menu and file dialogs

Tech Stack

Frontend React 19 · TanStack Start · Tailwind CSS v4 · shadcn/ui
Canvas CanvasKit/Skia (WASM, GPU-accelerated)
State Zustand v5
Server Nitro
Desktop Electron 35
CLI op — terminal control, batch design DSL, code export
AI Anthropic SDK · Claude Agent SDK · OpenCode SDK · Copilot SDK
Runtime Bun · Vite 7
File format .op — JSON-based, human-readable, Git-friendly

Project Structure

openpencil/
├── apps/
│   ├── web/                 TanStack Start web app
│   │   ├── src/
│   │   │   ├── canvas/      CanvasKit/Skia engine — drawing, sync, layout
│   │   │   ├── components/  React UI — editor, panels, shared dialogs, icons
│   │   │   ├── services/ai/ AI chat, orchestrator, design generation, streaming
│   │   │   ├── stores/      Zustand — canvas, document, pages, history, AI
│   │   │   ├── mcp/         MCP server tools for external CLI integration
│   │   │   ├── hooks/       Keyboard shortcuts, file drop, Figma paste
│   │   │   └── uikit/       Reusable component kit system
│   │   └── server/
│   │       ├── api/ai/      Nitro API — streaming chat, generation, validation
│   │       └── utils/       Claude CLI, OpenCode, Codex, Copilot wrappers
│   ├── desktop/             Electron desktop app
│   │   ├── main.ts          Window, Nitro fork, native menu, auto-updater
│   │   ├── ipc-handlers.ts  Native file dialogs, theme sync, prefs IPC
│   │   └── preload.ts       IPC bridge
│   └── cli/                 CLI tool — `op` command
│       ├── src/commands/    Design, document, export, import, node, page, variable commands
│       ├── connection.ts    WebSocket connection to running app
│       └── launcher.ts      Auto-detect and launch desktop app or web server
├── packages/
│   ├── pen-types/           Type definitions for PenDocument model
│   ├── pen-core/            Document tree ops, layout engine, variables
│   ├── pen-codegen/         Code generators (React, HTML, Vue, Flutter, ...)
│   ├── pen-figma/           Figma .fig file parser and converter
│   ├── pen-renderer/        Standalone CanvasKit/Skia renderer
│   └── pen-sdk/             Umbrella SDK (re-exports all packages)
└── .githooks/               Pre-commit version sync from branch name

Keyboard Shortcuts

Key Action Key Action
V Select Cmd+S Save
R Rectangle Cmd+Z Undo
O Ellipse Cmd+Shift+Z Redo
L Line Cmd+C/X/V/D Copy/Cut/Paste/Duplicate
T Text Cmd+G Group
F Frame Cmd+Shift+G Ungroup
P Pen tool Cmd+Shift+E Export
H Hand (pan) Cmd+Shift+C Code panel
Del Delete Cmd+Shift+V Variables panel
[ / ] Reorder Cmd+J AI chat
Arrows Nudge 1px Cmd+, Agent settings
Cmd+Alt+U Boolean union Cmd+Alt+S Boolean subtract
Cmd+Alt+I Boolean intersect

Scripts

bun --bun run dev          # Dev server (port 3000)
bun --bun run build        # Production build
bun --bun run test         # Run tests (Vitest)
npx tsc --noEmit           # Type check
bun run bump <version>     # Sync version across all package.json
bun run electron:dev       # Electron dev
bun run electron:build     # Electron package
bun run cli:dev            # Run CLI from source
bun run cli:compile        # Compile CLI to dist

Contributing

Contributions are welcome! See CLAUDE.md for architecture details and code style.

  1. Fork and clone
  2. Set up version sync: git config core.hooksPath .githooks
  3. Create a branch: git checkout -b feat/my-feature
  4. Run checks: npx tsc --noEmit && bun --bun run test
  5. Commit with Conventional Commits: feat(canvas): add rotation snapping
  6. Open a PR against main

Roadmap

  • Design variables & tokens with CSS sync
  • Component system (instances & overrides)
  • AI design generation with orchestrator
  • MCP server integration with layered design workflow
  • Multi-page support
  • Figma .fig import
  • Boolean operations (union, subtract, intersect)
  • Multi-model capability profiles
  • Monorepo restructure with reusable packages
  • CLI tool (op) for terminal control
  • Collaborative editing
  • Plugin system

Contributors

Contributors

Community

Discord Join our Discord — Ask questions, share designs, suggest features.

Star History

Star History Chart

License

MIT — Copyright (c) 2026 ZSeven-W