# OpenPencil Skill

An LLM skill that teaches an AI coding agent how to design with OpenPencil, covering its command-line tool, a batch design DSL, MCP design tools and general design conventions.

The skill follows the agentskills.io specification and installs into Claude Code, Cursor, Codex, OpenCode or Gemini CLI, after the separate op command-line tool has been installed and connected to a running OpenPencil desktop app or web server. Once installed, asking an agent to design something with OpenPencil causes it to generate PenNode design documents through the op CLI or MCP tools automatically.

Included material covers the full op CLI reference for app control, document operations, nodes, import, export, templates, layout, pages, variables and code generation, a batch design DSL with a sandboxed JavaScript mode, the PenNode schema for the current OpenPencil version, more than 40 semantic component roles with sensible defaults, general design principles for typography, color and spacing, layout and sizing rules, a layered MCP workflow that goes from a skeleton to content to refinement, and support for importing SVG, HTML pages and captured web snapshots.

Website: https://github.com/ZSeven-W/openpencil-skill