Unreal Engine MCP Server

A comprehensive Model Context Protocol (MCP) server that enables AI assistants to control Unreal Engine through a native C++ Automation Bridge plugin. Built with TypeScript, C++, and Rust (WebAssembly).

Table of Contents

• Features
• Getting Started
• Configuration
• Available Tools
• WebAssembly Acceleration
• GraphQL API
• Docker
• Documentation
• Community
• Development
• Contributing

Features

| Category | Capabilities | |----------|-------------| | Asset Management | Browse, import, duplicate, rename, delete assets; create materials | | Actor Control | Spawn, delete, transform, physics, tags, components | | Editor Control | PIE sessions, camera, viewport, screenshots, bookmarks | | Level Management | Load/save levels, streaming, World Partition, data layers | | Animation & Physics | Animation BPs, state machines, ragdolls, vehicles, constraints | | Visual Effects | Niagara particles, GPU simulations, procedural effects, debug shapes | | Sequencer | Cinematics, timeline control, camera animations, keyframes | | Graph Editing | Blueprint, Niagara, Material, and Behavior Tree graph manipulation | | Audio | Sound cues, audio components, sound mixes, ambient sounds | | System | Console commands, UBT, tests, logs, project settings, CVars |

Architecture

• Native C++ Automation — All operations route through the MCP Automation Bridge plugin
• Dynamic Type Discovery — Runtime introspection for lights, debug shapes, and sequencer tracks
• Graceful Degradation — Server starts even without an active Unreal connection
• On-Demand Connection — Retries automation handshakes with exponential backoff
• Command Safety — Blocks dangerous console commands with pattern-based validation
• Asset Caching — 10-second TTL for improved performance
• Metrics Rate Limiting — Per-IP rate limiting (60 req/min) on Prometheus endpoint
• Centralized Configuration — Unified class aliases and type definitions

Getting Started

Prerequisites

• Node.js 18+
• Unreal Engine 5.0–5.7

Step 1: Install MCP Server

Option A: NPX (Recommended)

npx unreal-engine-mcp-server

Option B: Clone & Build

git clone https://github.com/ChiR24/Unreal_mcp.git
cd Unreal_mcp
npm install
npm run build
node dist/cli.js

Step 2: Install Unreal Plugin

The MCP Automation Bridge plugin is included at Unreal_mcp/plugins/McpAutomationBridge.

Method 1: Copy Folder

Copy:  Unreal_mcp/plugins/McpAutomationBridge/
To:    YourUnrealProject/Plugins/McpAutomationBridge/

Regenerate project files after copying.

Method 2: Add in Editor

1. Open Unreal Editor → Edit → Plugins
2. Click "Add" → Browse to Unreal_mcp/plugins/
3. Select the McpAutomationBridge folder

Video Guide:

https://github.com/user-attachments/assets/d8b86ebc-4364-48c9-9781-de854bf3ef7d

⚠️ First-Time Project Open: When opening the project directly (double-click .uproject) for the first time, UE will prompt "Would you like to rebuild them now?" for missing modules. Click Yes to rebuild. After the rebuild completes, you may still see: "Plugin 'McpAutomationBridge' failed to load because module could not be loaded." This is expected — UE rebuilds successfully but doesn't reload the plugin in the same session. Simply close and reopen the project and the plugin will load correctly. Alternatively, build via Visual Studio first to avoid this.

Step 3: Enable Required Plugins

Enable via Edit → Plugins, then restart the editor:

| Plugin | Required For | |--------|--------------| | MCP Automation Bridge | All automation operations | | Editor Scripting Utilities | Asset/Actor subsystem operations | | Sequencer | Sequencer tools | | Level Sequence Editor | manage_sequence operations | | Control Rig | animation_physics operations | | Subobject Data Interface | Blueprint components (UE 5.7+) | | Geometry Script | manage_geometry operations (procedural mesh) |

Step 4: Configure MCP Client

Add to your Claude Desktop / Cursor config file:

Using Clone/Build:

{
  "mcpServers": {
    "unreal-engine": {
      "command": "node",
      "args": ["path/to/Unreal_mcp/dist/cli.js"],
      "env": {
        "UE_PROJECT_PATH": "C:/Path/To/YourProject",
        "MCP_AUTOMATION_PORT": "8091"
      }
    }
  }
}

Using NPX:

{
  "mcpServers": {
    "unreal-engine": {
      "command": "npx",
      "args": ["unreal-engine-mcp-server"],
      "env": {
        "UE_PROJECT_PATH": "C:/Path/To/YourProject"
      }
    }
  }
}

Configuration

Environment Variables

# Required
UE_PROJECT_PATH="C:/Path/To/YourProject"

# Automation Bridge
MCP_AUTOMATION_HOST=127.0.0.1
MCP_AUTOMATION_PORT=8091

# LAN Access (optional)
# SECURITY: Set to true to allow binding to non-loopback addresses (e.g., 0.0.0.0)
# Only enable if you understand the security implications.
MCP_AUTOMATION_ALLOW_NON_LOOPBACK=false

# Logging
LOG_LEVEL=info  # debug | info | warn | error

# Optional
WASM_ENABLED=true
MCP_AUTOMATION_REQUEST_TIMEOUT_MS=120000
ASSET_LIST_TTL_MS=10000

LAN Access Configuration

By default, the automation bridge only binds to loopback addresses (127.0.0.1) for security. To enable access from other machines on your network:

TypeScript (MCP Server):

MCP_AUTOMATION_ALLOW_NON_LOOPBACK=true
MCP_AUTOMATION_HOST=0.0.0.0

Unreal Engine Plugin:

1. Go to Edit → Project Settings → Plugins → MCP Automation Bridge
2. Under Security, enable "Allow Non Loopback"
3. Under Connection, set "Listen Host" to 0.0.0.0
4. Restart the editor

⚠️ Security Warning: Enabling LAN access exposes the automation bridge to your local network. Only use on trusted networks with appropriate firewall rules.

Available Tools

| Tool | Description | |------|-------------| | manage_asset | Assets, Materials, Render Targets, Behavior Trees | | control_actor | Spawn, delete, transform, physics, tags | | control_editor | PIE, Camera, viewport, screenshots | | manage_level | Load/Save, World Partition, streaming | | manage_lighting | Spawn lights, GI, shadows, build lighting, list_light_types | | manage_performance | Profiling, optimization, scalability | | animation_physics | Animation BPs, Vehicles, Ragdolls, Control Rig, IK, Blend Spaces | | manage_effect | Niagara, Particles, Debug Shapes, Niagara authoring, GPU sim | | manage_blueprint | Create, SCS, Graph Editing, Node manipulation | | build_environment | Landscape, Foliage, Procedural | | system_control | UBT, Tests, Logs, Project Settings, CVars | | manage_sequence | Sequencer / Cinematics, list_track_types | | inspect | Object Introspection | | manage_audio | Audio Assets, Components, Sound Cues, MetaSounds, Attenuation | | manage_behavior_tree | Behavior Tree Graph Editing | | manage_input | Enhanced Input Actions & Contexts | | manage_geometry | Procedural mesh creation (Geometry Script) | | manage_skeleton | Skeleton, sockets, physics assets, cloth binding | | manage_material_authoring | Material creation, expressions, landscape layers | | manage_texture | Texture creation, modification, compression settings | | manage_gas | Gameplay Ability System: abilities, effects, attributes | | manage_character | Character creation, movement, advanced locomotion | | manage_combat | Weapons, projectiles, damage, melee combat | | manage_ai | AI controllers, EQS, perception, State Trees, Smart Objects | | manage_inventory | Items, equipment, loot tables, crafting | | manage_interaction | Interactables, destructibles, triggers | | manage_widget_authoring | UMG widget creation, layout, styling, animations | | manage_networking | Replication, RPCs, network prediction | | manage_game_framework | Game modes, game states, player controllers, match flow | | manage_sessions | Sessions, split-screen, LAN, voice chat | | manage_level_structure | Level creation, sublevels, World Partition, data layers, HLOD | | manage_volumes | Trigger volumes, blocking, physics, audio, navigation volumes | | manage_navigation | NavMesh settings, nav modifiers, nav links, smart links, pathfinding |

Supported Asset Types

Blueprints • Materials • Textures • Static Meshes • Skeletal Meshes • Levels • Sounds • Particles • Niagara Systems • Behavior Trees

WebAssembly Acceleration

Optional WASM acceleration for computationally intensive operations. Enabled by default when available, falls back to TypeScript automatically.

| Operation | Speedup | |-----------|---------| | JSON parsing | 5–8x | | Transform calculations | 5–10x | | Vector/matrix math | 5x | | Dependency resolution | 3–5x |

Building WASM (Optional)

Prerequisites:

1. Install Rust: https://rust-lang.org/tools/install/
2. Install wasm-pack: cargo install wasm-pack

npm run build:wasm       # Builds WASM

To disable: WASM_ENABLED=false

GraphQL API

Optional GraphQL endpoint for complex queries. Disabled by default.

GRAPHQL_ENABLED=true
GRAPHQL_PORT=4000

See GraphQL API Documentation.

Docker

docker build -t unreal-mcp .
docker run -it --rm -e UE_PROJECT_PATH=/project unreal-mcp

Documentation

| Document | Description | |----------|-------------| | Handler Mappings | TypeScript to C++ routing | | GraphQL API | Query and mutation reference | | WebAssembly Integration | WASM performance guide | | Plugin Extension | C++ plugin architecture | | Testing Guide | How to run and write tests | | Migration Guide v0.5.0 | Upgrade to v0.5.0 | | Roadmap | Development phases | | Automation Progress | Implementation status |

Development

npm run build       # Build TypeScript + WASM
npm run lint        # Run ESLint
npm run test:unit   # Run unit tests
npm run test:all    # Run all tests

Community

| Resource | Description | |----------|-------------| | Project Roadmap | Track development progress across 47 phases | | Discussions | Ask questions, share ideas, get help | | Issues | Report bugs and request features |

Contributing

Contributions welcome! Please:

• Include reproduction steps for bugs
• Keep PRs focused and small
• Follow existing code style

License

MIT — See LICENSE