@iflow-mcp/natfii-ue5-mcp-server
v1.3.1
Published
MCP server for Unreal Engine 5 editor integration - works with Claude Code, Claude Desktop, and any MCP-compatible AI client
Readme
UnrealClaude
Claude Code CLI integration for Unreal Engine 5.7 - Get AI coding assistance with built-in UE5.7 documentation context directly in the editor.
Supported Platforms: Windows (Win64) and Linux. Mac support is not yet available.
Overview
UnrealClaude integrates the Claude Code CLI directly into the Unreal Engine 5.7 Editor. Instead of using the API directly, this plugin shells out to the claude command-line tool, leveraging your existing Claude Code authentication and capabilities.
Key Features:
- Native Editor Integration - Chat panel docked in your editor with live streaming responses, tool call grouping, and code block rendering
- MCP Server - 20+ Model Context Protocol tools for actor manipulation, Blueprint editing, level management, materials, input, and more
- Dynamic UE 5.7 Context System - The MCP bridge includes a dynamic context loader that provides accurate UE 5.7 API documentation on demand
- Blueprint Editing - Create and modify Blueprints, Animation Blueprints, state machines (Few bugs still, don't rely on fully)
- Level Management - Open, create, and manage levels and map templates programmatically
- Asset Management - Search assets, query dependencies and referencers
- Async Task Queue - Long-running operations won't timeout
- Script Execution - Claude can write, compile (via Live Coding), and execute scripts with your permission
- Session Persistence - Conversation history saved across editor sessions
- Project-Aware - Automatically gathers project context (modules, plugins, assets) and is able to see editor viewports
- Uses Claude Code Auth - No separate API key management needed
Prerequisites
1. Install Claude Code CLI
npm install -g @anthropic-ai/claude-code2. Authenticate Claude Code
claude auth loginThis will open a browser window to authenticate with your Anthropic account (Claude Pro/Max subscription) or set up API access.
3. Verify Installation
claude --version
claude -p "Hello, can you see me?"Installation
(Check the Editor catagory in the plugin browser. You might need to scroll down for it if search doesn't pick it up)
Option A: Copy to Project Plugins (Recommended)
Prebuilt binaries for UE 5.7 Win64 are included - no compilation required. Linux users will need to build from source (see below).
Important: This repo uses Git LFS for binary files (
.dll,.pdb). You must have Git LFS installed before cloning, or the binaries will be downloaded as small placeholder files and the plugin will fail to load.git lfs install # one-time setup
- Clone this repository (do not use "Download ZIP" — it won't include the binaries)
- Copy the
UnrealClaudefolder to your project'sPluginsdirectory:YourProject/ ├── Content/ ├── Source/ └── Plugins/ └── UnrealClaude/ ├── Binaries/ │ └── Win64/ # Prebuilt binaries (Windows) ├── Source/ ├── Resources/ ├── Config/ └── UnrealClaude.uplugin - Install MCP Bridge dependencies (required for Blueprint tools and editor integration):
cd YourProject/Plugins/UnrealClaude/Resources/mcp-bridge npm install - Launch the editor - the plugin will load automatically
Option B: Engine Plugin (All Projects)
Copy to your engine's plugins folder:
Windows:
C:\Program Files\Epic Games\UE_5.7\Engine\Plugins\Marketplace\UnrealClaude\Linux:
/path/to/UnrealEngine/Engine/Plugins/Marketplace/UnrealClaude/Then install the MCP bridge dependencies:
cd <EnginePluginsPath>/UnrealClaude/Resources/mcp-bridge
npm installBuilding from Source
If you need to rebuild (different UE version, modifications, etc.):
Windows:
Engine\Build\BatchFiles\RunUAT.bat BuildPlugin -Plugin="PATH\TO\UnrealClaude.uplugin" -Package="OUTPUT\PATH" -TargetPlatforms=Win64Linux:
Engine/Build/BatchFiles/RunUAT.sh BuildPlugin -Plugin="/path/to/UnrealClaude.uplugin" -Package="/output/path" -TargetPlatforms=LinuxUsage
Opening the Claude Panel
Menu → Tools → Claude Assistant
Example Prompts
How do I create a custom Actor Component in C++?
What's the best way to implement a health system using GAS?
Explain World Partition and how to set up streaming for an open world.
Write a BlueprintCallable function that spawns particles at a location.
How do I properly use TObjectPtr<> vs raw pointers in UE5.7?Input Shortcuts
| Shortcut | Action |
|----------|--------|
| Enter | Send message |
| Shift+Enter | New line in input |
| Escape | Cancel current request |
Features
Session Persistence
Conversations are automatically saved to your project's Saved/UnrealClaude/ directory and restored when you reopen the editor. The plugin maintains conversation context across sessions.
Project Context
UnrealClaude automatically gathers information about your project:
- Source modules and their dependencies
- Enabled plugins
- Project settings
- Recent assets
- Custom CLAUDE.md instructions
MCP Server
The plugin includes a Model Context Protocol (MCP) server with 20+ tools that expose editor functionality to Claude and external tools. The MCP server runs on port 3000 by default and starts automatically when the editor loads.
Tool Categories:
- Actor Tools - Spawn, move, delete, inspect, and set properties on actors
- Level Management - Open levels, create new levels from templates, list available templates
- Blueprint Tools - Create and modify Blueprints (variables, functions, nodes, pins)
- Animation Blueprint Tools - Full state machine editing (states, transitions, conditions, batch operations)
- Asset Tools - Search assets, query dependencies and referencers with pagination
- Character Tools - Character configuration, movement settings, and data queries
- Material Tools - Material and material instance operations
- Enhanced Input Tools - Input action and mapping context management
- Utility Tools - Console commands, output log, viewport capture, script execution
- Async Task Queue - Background execution for long-running operations
For full MCP tool documentation with parameters, examples, and API details, see UnrealClaude's MCP Bridge repository.
Dynamic UE 5.7 Context System
The MCP bridge includes a dynamic context loader that provides accurate UE 5.7 API documentation on demand. Use unreal_get_ue_context to query by category (animation, blueprint, slate, actor, assets, replication) or search by keywords. Context status is shown in unreal_status output.
Configuration
Custom System Prompts
You can extend the built-in UE5.7 context by creating a CLAUDE.md file in your project root:
# My Project Context
## Architecture
- This is a multiplayer survival game
- Using Dedicated Server model
- GAS for all abilities
## Coding Standards
- Always use UPROPERTY for Blueprint access
- Prefix interfaces with I (IInteractable)
- Use GameplayTags for ability identificationAllowed Tools
By default, the plugin runs Claude with these tools: Read, Write, Edit, Grep, Glob, Bash. You can modify this in ClaudeSubsystem.cpp:
Config.AllowedTools = { TEXT("Read"), TEXT("Grep"), TEXT("Glob") }; // Read-onlyHow It Works
- User enters a prompt in the editor widget
- Plugin builds context from UE5.7 knowledge + project information
- Executes:
claude -p --skip-permissions --append-system-prompt "..." "your prompt" - Claude Code runs with your project as the working directory
- Response is captured and displayed in the chat panel
- Conversation is persisted for future sessions
Command Line Equivalent
cd "C:\YourProject"
claude -p --skip-permissions \
--allowedTools "Read,Write,Edit,Grep,Glob,Bash" \
--append-system-prompt "You are an expert Unreal Engine 5.7 developer..." \
"How do I create a custom GameMode?"Troubleshooting
"Claude CLI not found"
- Verify Claude is installed:
claude --version - Check it's in your PATH:
where claude - Restart Unreal Editor after installation
"Authentication required"
Run claude auth login in a terminal to authenticate.
Responses are slow
Claude Code executes in your project directory and may read files for context. Large projects may have slower initial responses.
Plugin doesn't compile
Ensure you're on Unreal Engine 5.7. Supported platforms are Windows (Win64) and Linux.
MCP Server not starting
Check if port 3000 is available. The MCP server logs to LogUnrealClaude.
MCP tools not available / Blueprint tools not working
If Claude says the MCP tools are in its instructions but not in its function list:
Install MCP bridge dependencies: The most common cause is missing npm packages:
cd YourProject/Plugins/UnrealClaude/Resources/mcp-bridge npm installVerify the HTTP server is running: With the editor open, test:
curl http://localhost:3000/mcp/statusYou should see a JSON response with project info.
Check the Output Log: Look for
LogUnrealClaudemessages:MCP Server started on http://localhost:3000- Server is runningRegistered X MCP tools- Tools are loaded
Restart the editor: After installing npm dependencies, restart Unreal Editor.
Debugging the MCP Bridge
The MCP bridge is also available as a standalone repository with its own Vitest test suite. If you're experiencing bridge-level issues (tool listing, parameter translation, context injection), you can run the bridge tests independently:
cd path/to/ue5-mcp-bridge
npm install
npm testThis tests the bridge without requiring a running Unreal Editor.
Contributing
Feel free to fork for your own needs! Possible areas for improvement:
- [x] Linux support (thanks @bearyjd)
- [ ] Mac support
- [ ] Context menu integration (right-click on code)
- [ ] Blueprint node for runtime Claude queries
- [ ] Additional MCP tools
License
MIT License - See LICENSE file.
Credits
- Built for Unreal Engine 5.7
- Integrates with Claude Code by Anthropic
