Better UnrealClaude

Performance-optimized fork of UnrealClaude by Natfii Created by Athenox Development

Enhanced Claude Code CLI integration for Unreal Engine 5.7 with dynamic Blueprint node discovery, optimized token usage, and advanced workflow validation.

Windows Only - This plugin uses Windows-specific process APIs.

What's New in Better UnrealClaude

This fork adds major performance and reliability improvements to the original UnrealClaude plugin:

Key Enhancements

Dynamic Blueprint Node Discovery - Zero hardcoding! Auto-discovers all Blueprint nodes (functions, events, math ops) via reflection
73% Token Reduction - Optimized MCP tool descriptions and context
Smart Batch Validation - Pre-validates node references before execution, catching errors early
Behavior Tree Support - Full BT/Blackboard creation and modification tools
3-Step Blueprint Workflow - Documented best practices for reliable node creation
Intelligent Error Messages - Failed pin connections now suggest available pins
Caching System - 30s TTL cache for Blueprint metadata queries (+40% speed)
Batching system - Improving speed dramatically (-60% tool usage)

Overview

Better 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.

Core Features:

21 MCP Tools - Model Context Protocol server for comprehensive editor control
Dynamic UE 5.7 Context System - Accurate API documentation on demand
Blueprint Editing - Create and modify Blueprints with validated workflows
Behavior Trees - Full BT/Blackboard support with composite/task/decorator nodes
Animation Blueprints - State machine editing (states, transitions, conditions)
Level Management - Open, create, and manage levels programmatically
Asset Management - Search, dependencies, and referencer queries
Async Task Queue - Long-running operations with progress tracking
Script Execution - Write, compile (via Live Coding), and execute scripts
Session Persistence - Conversation history across editor sessions
Project-Aware - Auto-gathers project context and viewport info
Claude Code Auth - No separate API key management

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 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.

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 UnrealClaude folder to your project's Plugins directory:

YourProject/
├── Content/
├── Source/
└── Plugins/
    └── UnrealClaude/
        ├── Binaries/Win64/    # Prebuilt binaries
        ├── Source/
        ├── Resources/
        ├── Config/
        └── UnrealClaude.uplugin

Install MCP Bridge dependencies (required for Blueprint tools):

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:

C:\Program Files\Epic Games\UE_5.7\Engine\Plugins\Marketplace\UnrealClaude\

Then install the MCP bridge dependencies:

cd "C:\Program Files\Epic Games\UE_5.7\Engine\Plugins\Marketplace\UnrealClaude\Resources\mcp-bridge"
npm install

Building from Source

If you need to rebuild (different UE version, modifications, etc.):

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

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?

Create a Behavior Tree for an AI enemy with patrol and chase states.

Add a Delay node to this Blueprint function and connect it to a print statement.

Features

Session Persistence

Conversations are automatically saved by Claude Code, you can resume it with /resume.

Project Context

Better UnrealClaude automatically gathers information about your project:

Source modules and their dependencies
Enabled plugins
Project settings
Recent assets
Custom CLAUDE.md instructions

MCP Server & Tools

The plugin includes a Model Context Protocol (MCP) server with 21 specialized tools that expose editor functionality to Claude. The server runs on port 3000 by default and starts automatically when the editor loads.

Blueprint Tools

blueprint_query (Read-only)

list - List all Blueprints with filters
inspect - Get detailed Blueprint info (variables, functions, graphs)
get_graph - Get graph structure and nodes
search - Dynamically discover Blueprint nodes
get_node_pins - Get exact pin layout for functions
list_libraries - List all function libraries
list_library_functions - List functions in a library
search_events - Dynamically discover Event nodes (BeginPlay, Overlap, etc.)

blueprint_modify

create - Create new Blueprint
add_variable / remove_variable
add_function / remove_function
add_component - Add actor components
add_node - Create Blueprint nodes
delete_node - Remove nodes
connect_pins / disconnect_pins
set_pin_value - Set default pin values
batch - Multi-operation execution

New Workflow: See Blueprint Workflow Guide for the recommended 3-step approach to creating Blueprint nodes.

Behavior Tree Tools

behavior_tree_modify

Blackboard Operations:
- create_blackboard - Create new Blackboard Data asset
- get_blackboard_info - Query Blackboard structure
- add_key / remove_key / rename_key - Manage Blackboard keys
Behavior Tree Operations:
- create_behavior_tree - Create new BT with root node
- get_tree_info - Get complete tree structure
- add_composite - Add Selector/Sequence/Parallel nodes
- add_task - Add task nodes (Wait, MoveTo, custom)
- add_decorator / add_service - Attach decorators/services
- remove_node / move_node - Tree manipulation
- set_node_property - Configure node properties
- connect_to_blackboard - Link BT to Blackboard
- batch - Multi-operation execution

Animation Blueprint Tools

anim_blueprint_modify

State machine management
State creation and configuration
Transition setup (duration, priority)
Condition nodes (TimeRemaining, Greater, And, Or, GetVariable)
Batch operations

Actor & Level Tools

actor_query / actor_modify

Spawn, move, delete, inspect actors
Set properties with reflection
Component management

level_management

Open levels
Create from templates
List available templates

get_level_actors

Query actors by class/tag/name
Pagination support

Asset Tools

asset_search

Search by path, class, tag
Advanced filtering
Pagination (default 10, max 1000)

asset_relations

Get dependencies (hard/soft/recursive)
Find referencers
Asset graph traversal

asset_modify

Create, delete, rename, duplicate assets
Batch operations

Material Tools

material_modify

Material instance creation
Parameter setting (scalar, vector, texture)
Parent material queries

Character & Input Tools

character_management

Character configuration
Movement settings
Data asset operations
Stats table queries

enhanced_input

Input action creation
Mapping context management
Trigger and modifier setup

Utility Tools

editor_utils

Console command execution
Output log queries
Viewport capture
Editor state info

execute_script

Python/Blueprint script execution
Live coding integration
Result capture

task_queue (Async)

Background task execution
Progress tracking
Long-running operations

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 or search by keywords.

Available Categories:

animation - Animation Blueprints, state machines, blend spaces
blueprint - Blueprint editing, nodes, pins, graphs
slate - UI/Slate widget development
actor - Actor lifecycle, components, transforms
assets - Asset management, references, loading
replication - Network replication, RPCs
enhanced_input - Enhanced Input system
material - Material editing and instances
character - Character movement and configuration
parallel_workflows - Best practices for async operations

Context status is shown in unreal_status output.

🔍 Dynamic Node Discovery (New!)

Better UnrealClaude uses zero hardcoding for Blueprint nodes. All nodes are discovered dynamically via UE5 reflection:

Functions & Math Ops:

{
  "operation": "search",
  "keyword": "Delay"
}
// Returns: KismetSystemLibrary::Delay with exact pins

Events:

{
  "operation": "search_events",
  "keyword": "Overlap",
  "base_class": "Actor"
}
// Returns: ActorBeginOverlap, ActorEndOverlap, etc.

Pin Layout:

{
  "operation": "get_node_pins",
  "function_reference": "KismetSystemLibrary::Delay"
}
// Returns: [execute (in), then (out), Duration (in), ReturnValue (out)]

This means:

Always up-to-date - New UE5 functions automatically available
Project-aware - Discovers custom Blueprint functions
No maintenance - No need to update hardcoded lists

📋 3-Step Blueprint Workflow

To create Blueprint nodes reliably, follow this validated workflow:

Step 1: Discover

Use search or get_node_pins to find exact function names and pin layouts:

{"operation": "search", "keyword": "Delay"}

Step 2: Create

Create nodes one by one, capturing the returned IDs:

{"operation": "add_node", "node_type": "CallFunction", ...}
// Returns: {"node_id": "CallFunction_Delay_1"}

Step 3: Connect

Connect using exact IDs and pin names from previous steps:

{
  "operation": "connect_pins",
  "source_node_id": "CallFunction_Delay_1",
  "source_pin": "then",
  "target_node_id": "CallFunction_Print_2",
  "target_pin": "execute"
}

Full documentation: Blueprint Workflow Guide

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 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

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
MCP server provides 21 specialized tools for editor manipulation
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. The caching system helps with repeated queries.

Plugin doesn't compile

Ensure you're on Unreal Engine 5.7 for Windows. This plugin uses Windows-specific APIs.

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

Blueprint batch operations failing

If you see errors like "Node #5 not found":

The plugin now pre-validates batch operations
Remember: #N refers to the N-th node created, not the N-th operation
See Blueprint Workflow Guide

Pin connection errors

When connections fail, the error now lists available pins:

Pin 'ReturnValue' not found on 'VariableGet_Delay_2'.
Available pins: [Delay (output)]

Use the suggested pins or query with get_node_pins first.

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:

Mac/Linux support
Additional MCP tools
Niagara system editing

License

MIT License - See LICENSE file.

Credits

Better UnrealClaude Fork:

Created by Athenox Development
GitHub: github.com/Athenox14/BetterUnrealClaude
Discord: discord.gg/4efJMvCVX9

Original UnrealClaude:

Built by Natfii
GitHub: github.com/Natfii/UnrealClaude

Powered by:

Unreal Engine 5.7 by Epic Games
Claude Code by Anthropic
Model Context Protocol (MCP) by Anthropic

Name		Name	Last commit message	Last commit date
Latest commit History 21 Commits
.github		.github
UnrealClaude		UnrealClaude
.gitignore		.gitignore
README.md		README.md

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Better UnrealClaude

What's New in Better UnrealClaude

Key Enhancements

Overview

Prerequisites

1. Install Claude Code CLI

2. Authenticate Claude Code

3. Verify Installation

Installation

Option A: Copy to Project Plugins (Recommended)

Option B: Engine Plugin (All Projects)

Building from Source

Usage

Opening the Claude Panel

Example Prompts

Features

Session Persistence

Project Context

MCP Server & Tools

Blueprint Tools

Behavior Tree Tools

Animation Blueprint Tools

Actor & Level Tools

Asset Tools

Material Tools

Character & Input Tools

Utility Tools

Dynamic UE 5.7 Context System

🔍 Dynamic Node Discovery (New!)

📋 3-Step Blueprint Workflow

Step 1: Discover

Step 2: Create

Step 3: Connect

Configuration

Custom System Prompts

Allowed Tools

How It Works

Command Line Equivalent

Troubleshooting

"Claude CLI not found"

"Authentication required"

Responses are slow

Plugin doesn't compile

MCP Server not starting

MCP tools not available / Blueprint tools not working

Blueprint batch operations failing

Pin connection errors

Debugging the MCP Bridge

Contributing

License

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