Pencil

As an AI design tool for developers, Pencil differs from most in one way: the canvas lives inside your IDE rather than in a separate app.

Pencil gives you an infinite design canvas in editors such as VSCode and Cursor, driven by agents, so screens and code stay aligned.

Its slogan is "Design right where you code," and the product follows it fairly literally.

Designs are saved in an open format that sits in your codebase.

They are versioned with Git like any other file, so you do not have to sync with an outside design service.

Pencil describes itself as an MCP canvas, which is how it connects agents to the design surface.

The canvas supports AI multiplayer, where several agents generate screens in parallel.

Precision tools give you more control than a single prompt box.

A vector-to-code workflow then turns the designs into production-ready, pixel-perfect applications.

Pencil suits engineers who want to prototype interfaces without leaving their editor, and teams that want design changes to appear in commit history.