Pencil is a Figma-like design canvas that lives inside your IDE (Cursor, VS Code) and feeds pixel-exact vector coordinates and design tokens to AI agents via MCP — so instead of guessing from a screenshot, Claude Code or Cursor agents get exact values and write code that matches the design 1:1. It supports bidirectional sync (visual edits update the codebase), Figma import, parallel multi-screen generation, and Git-versioned design files. Requires Claude Code; currently free during early access.