UE 5.8 setup

How to set up Unreal Engine 5.8's built-in MCP server

No third-party plugin. UE 5.8 already has an Experimental MCP server. Enable it, then any client that speaks MCP over local HTTP can connect. Epic names Claude Code, Cursor, and the MCP Inspector.

Steps below are from Epic's Unreal MCP in Unreal Editor page in the Unreal Engine 5.8 documentation.

Open a project in Unreal Engine 5.8.
Enable Unreal MCP and All Toolsets.
Edit > Plugins. Search Unreal MCP and check Enabled. The engine id is ModelContextProtocol. Search All Toolsets and enable that too. Toolset Registry turns on with them. Restart when asked. All Toolsets loads the default tools. You can enable single toolsets instead.
Start the server.
Edit > Editor Preferences > General > Model Context Protocol. Turn on Auto Start Server. Epic says it then binds to http://127.0.0.1:8000/mcp. The same panel sets the port (default 8000) and the path (default /mcp). The server name is unreal-mcp. Auto Start is off by default. To start by hand, open the console with the backtick key and run:
Editor console
```
ModelContextProtocol.StartServer
```
An optional port is allowed: ModelContextProtocol.StartServer 8000. The editor flag -ModelContextProtocolStartServer starts it even when Auto Start is off.
Write the client file.
From that console. Supported names are ClaudeCode, Cursor, VSCode, Gemini, Codex, and All.
Claude Code
```
ModelContextProtocol.GenerateClientConfig ClaudeCode
```
Cursor
```
ModelContextProtocol.GenerateClientConfig Cursor
```
Epic prints this JSON for Claude Code and says the command writes .mcp.json in the project root:
.mcp.json (Claude Code, as Epic prints it)
```
{
  "mcpServers": {
    "unreal-mcp": {
      "type": "http",
      "url": "http://127.0.0.1:8000/mcp"
    }
  }
}
```
For Cursor, run ModelContextProtocol.GenerateClientConfig Cursor and use the file it writes. JSON configs for Claude Code, Cursor, VS Code, and Gemini are merged if one already exists. Codex uses TOML and will not overwrite an existing file.
Open the agent from the project root, after the editor is up.
Epic's test lines: "What actors do I have selected?" and "What are a few things you can do in Unreal?"

Security

Loopback only. It binds to localhost and rejects a non-loopback Origin.
No authentication. Epic says it is not safe to expose past your machine.
Tool calls run one at a time on the game thread.
HTTP and Server-Sent Events only. stdio and WebSocket are not supported.

If it fails

Check the Output Log. Auto-start logs the address, port, and path. A taken port or a missing plugin shows up there.
Launch the agent from the project root, where the config was written, and only after the editor is open. Reconnect if the agent started first.
An empty tool list means All Toolsets (or the toolsets you wanted) is off. Unreal MCP does not include the tools by itself.
Codex still shows an old file because its TOML config is write-once. Delete that file, then run the command again.

Source: Unreal MCP in Unreal Editor, Unreal Engine 5.8 Documentation, Epic Developer Community.