Write HTML. Watch it land on the canvas.

Paper is a design file your agent can actually read and write. Same nodes, same CSS, no translation layer.

welcome.paper

New node

Settings

Display, notifications, and billing — written as HTML, sitting on the canvas.

Save changes

What it does

01

A real canvas, not a preview

Artboards, nodes, and CSS live in the file. You can grab a layer and keep editing after the agent is done.
02

Agents read and write the same nodes

MCP exposes the open file. Inspect selection, write HTML, update styles, export. The file is the API.
03

Export is the design, not a guess

JSX, computed CSS, and image fills come off the node tree. What you see is what ships.

How it works

Desktop starts a local MCP server on the open document. Web files and the dashboard do not.

HTTP to 127.0.0.1:29979/mcp. Grok, Cursor, Claude Code, Codex — same server.

The agent writes nodes. You grab a layer. Nobody waits on a handoff.

The MCP server only runs when a design file is open in Paper Desktop.