Pencil is an AI-assisted interface design application that connects visual design directly with software development. Its infinite canvas provides a workspace for creating application screens, website layouts, and reusable interface components. AI agents can generate design variations, build complete flows, and modify existing elements through natural language instructions. The editor supports manual design refinement alongside automated generation. MCP integration connects the canvas with development environments and external AI coding assistants. Designs use an open .pen file format that can be stored in source code repositories and tracked through Git. Figma content can be imported to accelerate existing design workflows. Export functionality converts designs into web code and visual assets. Pencil was subsequently renamed Pen, with this repository retaining its earlier desktop releases.
Features
- Infinite visual design canvas for websites, application screens, and interface prototypes
- AI-powered layout generation and component editing through natural language prompts
- Parallel design exploration using connected AI coding agents and MCP tools
- Reusable design components and integration with existing interface design systems
- Git-compatible .pen files with Figma importing and editable vector elements
- HTML and CSS code generation with visual asset exporting for development workflows