Unicorn Studio MCP
Your AI agent can now design with Unicorn Studio. Connect Cursor, Claude, or Codex over MCP, describe what you want, and watch it build in your open editor: custom shaders written and checked against the same rules as Unicorn Agent, tuned effects from the library, text and images laid out in the scene, timeline animations, scroll, and hover events. The agent renders every shader change and looks at the result before it touches your design, so it can catch and fix its own mistakes. Everything it commits is a normal edit, one undo step at a time, and you can keep tweaking it by hand. When the scene is ready, the agent can publish it and drop the embed into the codebase it's already working in, so you can go from idea to a live effect on your site in a single conversation.
MCP is in early access for Legend subscribers.
Getting started
1. Connect your agent
Open a project and click Connect your agent in the top bar, next to Unicorn Agent. Pick your agent and follow the steps. You can also open the same dialog from the Agents section of your account page.
The first time your agent uses Unicorn Studio, it opens your browser to sign in and approve the connection.
2. Allow agents
In the editor, open the dialog again (once your agent is signed in, the button reads Connected) and turn on Allow agents in this browser at the bottom. This lets connected agents read and edit the projects you have open. It stays on for every editor tab in this browser until you turn it off.
A green dot next to Connected means this tab is ready for your agent. Yellow means it's still connecting, which takes a moment when the editor loads or after your network drops.
3. Run your first prompt
Keep the project open and ask your agent:
A few more to try:
Supported agents
Unicorn Studio works with any MCP client that supports remote servers over HTTP with OAuth sign-in. The server URL is:
Cursor: click Add to Cursor in the Connect your agent dialog, or add this to ~/.cursor/mcp.json:
Claude Code: run this in your terminal, then run /mcp in Claude Code, choose unicorn-studio, and approve the connection in your browser.
Claude.ai (web and desktop): open Settings → Connectors, add a custom connector named Unicorn Studio with the server URL, then click Connect and approve.
Codex: run this in your terminal. Codex opens your browser to approve the connection. If it doesn't, run codex mcp login unicorn-studio.
ChatGPT: turn on Developer mode in Settings → Security and login. Then open ChatGPT Plugins, create a new MCP app named Unicorn Studio, and paste the server URL. Approve the connection, then add Unicorn Studio from the tools menu in a new chat. Developer mode availability depends on your account and workspace settings.
Other agents: add the server URL as a remote (HTTP) MCP server. Check your agent's docs for where its MCP config lives.
How it works
Which tab the agent works in
Allow agents is one setting for the whole browser, so every editor tab you open while it's on can take agent work. Tabs that were already open connect the next time they load.
When a chat starts, the agent picks the tab you used last. It stays in that tab for the rest of the chat, even if you switch to another one, so two chats can work in two tabs at the same time.
If no editor tab is open, the agent gets a link to your project or dashboard. Agents that can run commands open it for you; otherwise they'll ask you to.
While the agent is working
When the agent starts editing or creating an effect, the editor locks that scene so your edits and the agent's don't collide. The scene gets a purple border and a loader, and its label shows what the agent is doing in a few words. While the locked scene is open, the layers, properties, timeline, and most shortcuts are paused. Other scenes aren't locked: click one in the scenes panel or on the canvas to keep working there. The agent keeps track of its own scene, so when it makes its next change, the editor switches back to that scene rather than letting the change land in yours.
The scene unlocks when the agent commits its change, adds a library effect, or says it's done. It also unlocks after 5 minutes without agent activity. To stop the agent at any point, click Take control next to the scene's name. Any previews it hasn't committed are discarded.
Previews and undo
Shader edits and new effects are built as previews first. The agent validates the shader with the real WebGL compiler, renders it offscreen, and looks at the image, and nothing in your design changes until it commits. If you change the layer while the agent is previewing, its commit is rejected so it can't overwrite your change.
Every commit is one undo step and saves the design, so Cmd+Z works exactly as it does for your own edits. Changes to controls, animations, layers, and scenes skip the preview step and apply as single undo steps too.
Credits
MCP runs on your agent's own model, so tool calls don't use your AI credits.
Managing connections
Connected agents are listed in the Agents section of your account page, with when each one connected and was last used. Revoke access signs that agent out within about 30 seconds. It will need your approval again to reconnect. Your other agents stay connected.
If something's off
- The agent can't see Unicorn Studio's tools: restart your agent, or reload its MCP servers, so it picks up the new server.
- The agent says no editor tab is connected: make sure a project is open, Allow agents is on, and the dot next to Connected is green. Reload a tab that was open before you turned it on.
- The agent loses track of the tab after a reload: a reload gives the tab a new connection. Ask the agent to check the editor state again.
What is MCP?
MCP (Model Context Protocol) is an open standard that lets AI agents use tools from other apps. Unicorn Studio's MCP server gives your agent the same abilities you have in the editor, so the agent you already use for code can design, animate, and ship WebGL scenes too.