UEBlueprintMCP

A Model Context Protocol (MCP) server for AI-assisted Unreal Engine 5.7+ Blueprint manipulation with persistent TCP connections and auto-save.

Features

• 60+ MCP Commands for Blueprints, Materials, Widgets, Enhanced Input, and Editor control
• Persistent TCP Connection - Socket stays open between commands (port 55558)
• Auto-Save - Dirty packages saved automatically after every successful operation
• Crash Protection - All operations flow through a validation/execution pipeline
• String-Based Resolution - Accept Blueprint names, asset paths, or engine class names

Supported Operations

Category	Commands
Blueprints	Create, compile, add components, set properties
Graph Nodes	Events, functions, variables, branches, casts, spawns
Event Dispatchers	Create, bind, and call multicast delegates
Enhanced Input	Create Input Actions, Mapping Contexts, key bindings
Materials	Create materials, add expressions, connect nodes, post-process
UMG Widgets	Create widgets, add text/buttons, bind events
Editor	Spawn actors, viewport control, save operations

Setup

1. Install the Unreal Plugin

Copy or symlink UnrealPlugin/UEBlueprintMCP/ to your project's Plugins/ folder, then rebuild.

2. Set Up the Python MCP Server

cd Python
python -m venv venv
venv\Scripts\activate  # Windows
pip install -r requirements.txt

3. Configure MCP Client

Add to your project's .mcp.json:

{
  "mcpServers": {
    "unreal-mcp": {
      "command": "path/to/UEBlueprintMCP/Python/venv/Scripts/python.exe",
      "args": ["-m", "ue_blueprint_mcp.server"]
    }
  }
}

4. Launch

1. Open your Unreal project (plugin starts TCP server on port 55558)
2. Connect your MCP client (e.g., Claude Code with /mcp)

Architecture

MCP Client (Claude Code, etc.)
    |
    v  MCP Protocol
Python Server (ue_blueprint_mcp)
    |
    v  TCP/JSON (port 55558, persistent)
C++ Plugin (MCPBridge)
    |
    v  Action dispatch
FEditorAction subclasses
    |
    v  Validate -> Execute -> Auto-Save
Unreal Editor

All editor operations flow through FEditorAction subclasses that provide:

• Pre-execution validation
• Graceful error handling with descriptive messages
• Automatic dirty package tracking and save

Documentation

• CLAUDE.md - Architecture details and contribution guidelines
• docs/SKILL.md - Full command reference for Claude Code

Requirements

• Unreal Engine 5.7+
• Python 3.10+
• Visual Studio 2022 (for plugin builds)

License

MIT