UnrealClaude

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), Linux, and macOS (Apple Silicon). Claude Opus 4.7 and its Claude Code release supported.

Overview

UnrealClaude integrates the Claude Code CLI directly into the Unreal Engine 5.7 Editor and runs a MCP server for access to other coding agents.

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-code

2. Authenticate Claude Code

claude auth login

This 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 category in the plugin browser. You might need to scroll down for it if search doesn’t pick it up)

Step 1: Clone and Build

This plugin must be built from source for your platform and engine version. No prebuilt binaries are included.

1. Clone this repository (includes the MCP bridge submodule):

   git clone --recurse-submodules https://github.com/Natfii/UnrealClaude.git
   

   If you already cloned without --recurse-submodules, run:

   cd UnrealClaude
   git submodule update --init
   

2. Build the plugin:

   Windows:

   Engine\Build\BatchFiles\RunUAT.bat BuildPlugin -Plugin="PATH\TO\UnrealClaude\UnrealClaude\UnrealClaude.uplugin" -Package="OUTPUT\PATH" -TargetPlatforms=Win64
   

   Linux:

   Engine/Build/BatchFiles/RunUAT.sh BuildPlugin -Plugin="/path/to/UnrealClaude/UnrealClaude/UnrealClaude.uplugin" -Package="/output/path" -TargetPlatforms=Linux
   

   macOS:

   Engine/Build/BatchFiles/RunUAT.sh BuildPlugin -Plugin="/path/to/UnrealClaude/UnrealClaude/UnrealClaude.uplugin" -Package="/output/path" -TargetPlatforms=Mac
   

Step 2: Install the Plugin

Copy the built plugin to either your project or engine plugins folder.

Option A: Project Plugin (Recommended)

Copy the build output to your project’s Plugins directory:

YourProject/
├── Content/
├── Source/
└── Plugins/
    └── UnrealClaude/
        ├── Binaries/
        ├── Source/
        ├── Resources/
        ├── Config/
        └── UnrealClaude.uplugin

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/

Step 3: Install MCP Bridge Dependencies

Required for Blueprint tools and editor integration:

cd <PluginPath>/UnrealClaude/Resources/mcp-bridge
npm install

Step 4: Launch

Launch the editor - the plugin will load automatically.

Step 5: (Optional) Use with Claude Code CLI or Claude App

1. Launch Claude Code or Claude CLI and point it to your UnrealClaude install.

2. After the all clear, restart just Claude Code / CLI for changes to save.

macOS Quick Start (Apple Silicon)

For full details, see INSTALL_MAC.md.

1. Install Node.js and Claude Code CLI:

   brew install node
   npm install -g @anthropic-ai/claude-code
   claude
   

2. Install the plugin into your project’s Plugins/ directory
3. Install MCP bridge dependencies:

   cd YourProject/Plugins/UnrealClaude/Resources/mcp-bridge
   npm install
   

4. Launch the editor and open Tools > Claude Assistant

Linux Quick Start (Rocky/Fedora)

For full details, see INSTALL_LINUX.md.

1. Install Libraries:

   sudo dnf install -y nss nspr mesa-libgbm libXcomposite libXdamage libXrandr alsa-lib pciutils-libs libXcursor atk at-spi2-atk pango cairo gdk-pixbuf2 gtk3
   

2. Install Clipboard Support:

   sudo dnf install -y wl-clipboard   # Wayland
   sudo dnf install -y xclip          # X11 fallback
   

3. Setup Wayland:

   export SDL_VIDEODRIVER=wayland
   export UE_Linux_EnableWaylandNative=1
   

4. Build and Launch:

   ./UnrealEditor -vulkan
   

Usage

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

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

Scripting

Claude can write, compile (C++ via Live Coding), and run Python / Console / Editor Utility scripts — each gated by a permission dialog (deny-by-default; see Auto-approve script execution under Configuration).

Note — scripting & console tools are hidden by default. The MCP bridge does not advertise execute_script, run_console_command, cleanup_scripts, or get_script_history to the model. They’re a deliberate power-user fallback, kept off in releases so the model uses the structured editor tools (and to keep the tool list small). They remain callable by exact name, and every execution still passes through the C++ permission dialog. To surface them to the model, move the names out of HIDDEN_TOOL_NAMES in Resources/mcp-bridge/tool-router.js. run_console_command can reach the Python interpreter (py …) — treat un-hiding it as enabling arbitrary code execution; keep it to trusted setups only.

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

Project Settings

In Project Settings → Plugins → Unreal Claude:

• Auto-approve script execution (default: OFF) — when ON, every Python / C++ / Console / Editor Utility script triggered through the MCP bridge or the in-editor chat runs immediately without showing the permission dialog. Each auto-approved script writes a LogUnrealClaude Log entry with its type and description so the audit trail is preserved. Designed for trusted MCP-driven / agent-driven workflows where the per-script confirmation becomes dominant friction; only enable on machines and projects where the connected client is trusted.

The setting is persisted to Config/DefaultEditor.ini under [/Script/UnrealClaude.UnrealClaudeSettings].

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 identification

Allowed 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-only

How It Works

1. User enters a prompt in the editor widget
2. Plugin builds context from UE5.7 knowledge + project information
3. Executes: claude -p --skip-permissions --append-system-prompt "..." "your prompt"
4. Claude Code runs with your project as the working directory
5. Response is captured and displayed in the chat panel
6. 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”

1. Verify Claude is installed: claude --version
2. Check it’s in your PATH: where claude
3. 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.

You might also have too many global Claude Code plugins enabled (i.e. Superpowers, ralp-loop, context7). The context for those plugins getting injected can cause slowdowns up to 3+ minutes.

Plugin doesn’t compile

Ensure you’re on Unreal Engine 5.7. Supported platforms are Windows (Win64), Linux, and macOS.

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:

1. Install MCP bridge dependencies: The most common cause is missing npm packages:

   cd YourProject/Plugins/UnrealClaude/Resources/mcp-bridge
   npm install
   

2. Verify the HTTP server is running: With the editor open, test:

   curl http://localhost:3000/mcp/status
   

   You should see a JSON response with project info.

3. Check the Output Log: Look for LogUnrealClaude messages:

   • MCP Server started on http://localhost:3000 - Server is running
   • Registered X MCP tools - Tools are loaded

4. Restart the editor: After installing npm dependencies, restart Unreal Editor.

Request Hangs

New watchdog should warn about hung requests (60s). Make sure all files are on disk (DISABLE OneDrive, DropBox, etc.)

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 test

This tests the bridge without requiring a running Unreal Editor.

Contributing

Feel free to fork for your own needs! Possible areas for improvement:

• Linux support (thanks @bearyjd)
• Mac support (thanks @lateralsummer)
• Additional MCP tools (current tools need refractoring, no new ones for now)

License

MIT License - See LICENSE file.

Credits

• Built for Unreal Engine 5.7
• Integrates with Claude Code by Anthropic