Connect an agent

Design Editor runs an MCP server on your computer. Any agent that speaks MCP can read and edit the canvas you have open.

1Start the MCP server

The server listens on http://127.0.0.1:3100/mcp. It starts with the app once you have turned on an agent integration. Otherwise start it from Settings, MCP, from the Start server button on Home, or with de start.

The server only answers your own computer. It binds to 127.0.0.1 and refuses requests from web pages on other origins.

2Set it up in one click

Open Settings, MCP (or Connect an agent on Home) and turn on the agents you use. The app writes the entry into each agent's own config file. Restart the agent's terminal afterwards, and turn the switch on again after upgrading an agent.

3Or add it by hand

For Claude Code:

Terminal

claude mcp add --scope user --transport http design-editor http://127.0.0.1:3100/mcp

Other agents take the same URL in their MCP settings. Other agents lists the file each one reads.

4Check the connection

Ask the agent to call get_editor_state. It answers with the open document, the current page and the selection. From there, ask for a screen in plain words and watch it appear on the canvas.