What MCP gives you in Unreal Engine
MCP, the Model Context Protocol, is how an AI agent calls tools. Point an MCP client at the Unreal Editor and the agent stops guessing node names from memory: it asks the engine, acts, and sees the result.
Epic added an experimental MCP server to Unreal Engine 5.8 (Epic documentation). The server in Ultimate Engine CoPilot is separate: it works on Unreal Engine 5.5 to 5.8 and exposes the plugin's tools for Blueprints, materials, Niagara, PCG, animation, UI, Sequencer, play tests, profiling and more.
MCP works both ways here. Out: external clients use the CoPilot's tools. In: other MCP servers, such as a documentation lookup or your studio's own tools, plug into the CoPilot so its AI can call them.
Connect a client in three steps
- Open the MCP screen in the plugin. The server starts with the editor, there is nothing to switch on.
- Pick your client's tab (Claude Desktop, Claude Code, Cursor or Other) and press Copy. The snippet already contains your URL and token.
- Paste it into the client. Ask it something like "list the actors in my level".
For Claude Code the command looks like this, with your own token:
claude mcp add --scope user --header "Authorization: Bearer <token>" --transport http uecp-myproject http://localhost:9876/uecp/MyProject/mcpCursor reads the same snippet from .cursor/mcp.json. Claude Desktop connects through a small extension that ships with the plugin. Codex, Gemini CLI, Cline, VS Code and JetBrains take an HTTP MCP server with a bearer header: use the URL and header from the Other tab.
What a connected agent can do
Everything the in-editor chat can do. The client sees a small set of discovery tools, searches the catalogue with them and calls any of the 1,655 tools.
- Build and edit Blueprint graphs, then compile them.
- Create materials, Niagara systems, PCG graphs, widgets, behavior trees and Sequencer cinematics.
- Place, move and delete actors, and read what is in your level and project.
- Write and compile C++, or convert a Blueprint to a C++ class.
- Play the level, run multiplayer tests and profile frame time.
Several editors, one port, one token
Each open editor gets its own server and they share one address, port 9876. The project name in the URL picks the editor, so a studio with two projects open needs one entry per project in the client, not a second token or port.
The token is created the first time the plugin starts and survives restarts. If you paste it somewhere public, press Rotate and the old token stops working at once. LAN access, for clients on other machines in your network, is a switch on the same screen.
An external client is not held back by the interaction modes and confirm prompts of the in-editor chat: it can do whatever its own settings allow. Connect only clients you trust, and use your client's own approval settings.
Frequently asked questions
Do I need Epic's experimental MCP server to use this?
No. Ultimate Engine CoPilot runs its own MCP server inside the editor and works on Unreal Engine 5.5 to 5.8.
Which MCP clients work?
Claude Desktop, Claude Code, Cursor, Codex, Gemini CLI, Cline, VS Code and JetBrains, plus any client that can talk to an HTTP MCP server with a bearer token.
Does the AI model run on my machine?
The MCP server runs on your PC and listens on localhost. The model belongs to your agent: it can be a cloud model, or a local one in a client that supports local models.
Can I connect more than one project?
Yes. Each open editor gets its own endpoint on the same port, picked by the project name in the URL.