unreal-mcp-ue4

UE4.27.2-focused MCP server for Unreal Engine using Unreal Python Remote Execution

unreal-mcp-ue4 started from the core idea and early workflow shape of runreal/unreal-mcp, but it has since been heavily refactored for Unreal Engine 4.27.2 and expanded with many new tools, UE4-specific compatibility layers, documentation, and smoke coverage. At this point, the original inspiration remains, but the public surface and day-to-day behavior are substantially different and UE4-first.

This port and the follow-up tool, documentation, and smoke-test work were developed with assistance from OpenAI Codex.

This project is still under active development, so bugs, rough edges, and UE4.27-specific limitations may still surface.

Published package: unreal-mcp-ue4
Registry name: io.github.conaman/unreal-mcp-ue4

Overview

• No custom Unreal C++ plugin from this repository is required.
• The server talks to the editor through Unreal's built-in Python Remote Execution path.
• The tool surface is organized into granular tools and higher-level tool namespaces.
• UE5-only editor scripting features are not reintroduced; UE4.27-safe operations work normally, while unreliable graph or binding flows are either excluded from the MCP surface or return a clear message instead of silently failing.

Origin

• Original inspiration and starting point: runreal/unreal-mcp
• The current codebase has gone through extensive UE4.27-focused refactoring, architecture changes, and tool expansion.
• In practice, the shared idea is still visible, but the implementation, scope, and supported workflows now reflect a separate UE4-first project.
• Unreal Python API reference: Unreal Engine Python API 4.27

Safety

• This is not an official Epic Games project.
• Any connected MCP client can inspect and modify your open Unreal Editor session.
• Use a disposable test project first, especially when trying asset or world-generation tools.

Requirements

• Unreal Engine 4.27.2
• Node.js 18+
• npm
• An MCP client such as Codex, Claude Code, Claude Desktop, Cursor, or GitHub Copilot in a supported IDE

MCP Client Setup

This is the most important setup step: your MCP client must know how to launch unreal-mcp-ue4.

1. Install the server

Recommended global install:

npm install -g unreal-mcp-ue4

After the global install, use the published unreal-mcp-ue4 binary in your client configuration.

One-off invocation with npx:

npx unreal-mcp-ue4

Local source checkout:

git clone https://github.com/conaman/unreal-mcp-ue4.git
cd unreal-mcp-ue4
npm install
npm run build

Successful build output should create dist/bin.js, dist/index.js, and dist/editor/tools.js. Use the dist/bin.js path in the local source checkout examples below.

2. Register the server in your client

Use the global examples when you installed with npm install -g unreal-mcp-ue4. Use the local source checkout examples when you are developing from a cloned repository.

Claude

Global npm install:

claude mcp add --scope user unreal-mcp-ue4 -- unreal-mcp-ue4

Local source checkout:

claude mcp add --scope user unreal-mcp-ue4 -- node /absolute/path/to/unreal-mcp-ue4/dist/bin.js

Codex

Global npm install:

... [View full README on GitHub](https://github.com/conaman/unreal-mcp-ue4#readme)