UE5 Blueprint MCP Server

A Python-based MCP server that wraps Unreal Engine 5 (UE5) Blueprint APIs, enabling LLM-powered interactions with Blueprints. This allows AI agents to perform operations such as modifying Blueprints, editing visual scripting graphs, and managing variables, functions, and components.

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Features

The MCP server runs in streamable HTTP mode, built on FastMCP to call web APIs provided by a custom UE plugin. The plugin exposes a web API by wrapping UE Editor Utility C++ APIs, supporting:

Blueprint Management

• Create Blueprints
• Compile Blueprints
• Get Blueprint variables, functions, and graph details

Blueprint Functions

• Create, edit, and delete functions

Blueprint Visual Scripting

• Add function calls nodes
• Add custom or built-in events nodes
• Add variable getter/setter nodes
• Add generic, math, cast, and struct nodes
• Connect or break pin connections
• Set pin default values
• Get supported node types

Blueprint Variables

• Add, delete, rename, and set default values

Blueprint Components

• Get, add, rename, remove, or reparent components
• Get and set component properties

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Installation

1. Navigate to your project’s Plugins folder:

   cd <YourUEProject>/Plugins

2. Clone the repository:

   git clone https://github.com/cutehusky/ue5-mcp.git

3. Enable the plugin UE5_MCP in the UE5 Plugins tab.

4. (Optional) Create a Python environment.

5. Install Python dependencies for the MCP server:

   cd Python/MCP
   pip install mcp httpx python-dotenv

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Usage

Running the MCP Server

1. In the UE5 Editor, go to Windows > UE5_MCP to start the Blueprint API. Select the desired port.

2. Configure the .env file with your UE API endpoint:

   PORT=<your_port_to_run_mcp_server>
   UE5_REST_API_URL=http://localhost:<your_port>

3. Start the MCP server:

   python mcp_server.py

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Roadmap

• Support for more UE5 node types (e.g., animations, AI behaviors).
• Asset browser and asset management support.
• Tools to fetch UE documentation for LLMs.
• Enhanced error handling with detailed API failure messages.

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Contributing

You can contribute by:

• Adding more tools wrapping additional UE5 Blueprint APIs.
• Extending tooling to fetch UE documentation (built-in classes, graph nodes, methods).
• Improving tool docstrings with LLM-friendly guidance.
• Expanding graph manipulation to support additional node types.

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License

MIT License