Unity Copilot MCP Server

Control Unity Editor from AI assistants (GitHub Copilot, Claude, etc.) via the Model Context Protocol (MCP).

Demo Video

Watch the demo on YouTube

How It Works

AI Assistant (Copilot / Claude / etc.)
  ←— MCP (JSON-RPC over stdio) —→
unity-mcp.js (MCP Server)
  ←— WebSocket —→
Unity Editor (UnityBridgeServer on ws://127.0.0.1:6400)
  └─ UnityCommandHandler.cs (executes on main thread)
       └─ UnityEditor API (PrefabUtility, EditorSceneManager, …)

Setup

1. Install the Unity Bridge

use the VS Code command: Unity Copilot: Install Bridge into Unity Project.

The bridge server starts automatically when Unity enters Editor mode and listens on ws://127.0.0.1:6400.

2. Configure MCP Server (optional)

Add to your .vscode/mcp.json (workspace or user settings):

{
  "servers": {
    "unity": {
      "type": "stdio",
      "command": "node",
      "args": ["<path-to>/unity-mcp.js"]
    }
  }
}

3. Use with AI

The AI will automatically discover all available tools via MCP tools/list. Just ask it to do things in Unity — it knows what tools are available.

Examples:

• "Create a Cube at position 0,3,0 with a Rigidbody"
• "Find all GameObjects with Animator component"
• "Add BoxCollider to the Player object"
• "List all prefabs in the project"
• "Create a prefab called Enemy from Models/zombie.fbx"
• "Move the MainCamera to 0, 10, -5"

Available MCP Tools

Scene & Assets

Tool	Description
unity_ping	Check if Unity Editor bridge is alive
unity_refreshAssets	Force Unity to re-import assets and recompile scripts
unity_createScene	Create a new scene, optionally add to Build Settings
unity_openScene	Open a scene by name or path
unity_saveScene	Save the active scene to disk
unity_listAssets	Search project assets by type and folder

GameObjects

Tool	Description
unity_createGameObject	Create a primitive or empty GameObject in the scene
unity_createPrefab	Create a prefab asset from scratch or from a 3D model
unity_instantiatePrefab	Place an existing prefab into the scene
unity_deleteGameObject	Delete a GameObject from the scene (supports Undo)
unity_setProperty	Move, rotate, scale, rename, or toggle active state
unity_getSceneHierarchy	List all root GameObjects in the active scene
unity_findGameObjects	Search GameObjects by name with optional component filter

Components

Tool	Description
unity_addComponent	Add any component (built-in or custom script) to a GameObject
unity_setMaterial	Assign a material to a GameObject's Renderer
unity_setAnimatorController	Assign an AnimatorController to a GameObject
unity_getComponentProperties	Read all serialized properties of a component (use before setComponentProperty)
unity_setComponentProperty	Set a specific property on a component (float, int, bool, string, enum, Vector3, Color)

Editor Operations

Tool	Description
unity_runMenuItem	Execute any Unity Editor menu item by path (e.g. "AI/Bake", "Edit/Clear All PlayerPrefs")
unity_captureScreenshot	Capture the Scene view and return it as an inline PNG image
unity_undoRedo	Perform Undo or Redo in Unity Editor ("undo" / "redo")
unity_getUndoHistory	Get the current undo group index and name

Workflow: Adding a Custom Script

Since the AI can write files directly, the workflow for adding a custom script is:

1. AI creates the .cs file in your Unity project's Assets/ folder
2. AI calls unity_refreshAssets to force Unity to compile
3. AI calls unity_addComponent to attach the compiled script to a GameObject

Workflow: Editing a Component Property

1. AI calls unity_getComponentProperties to read all property names and current values
2. AI calls unity_setComponentProperty with the exact propertyName and new value

VS Code Extension (Chat Participant)

This project also includes a VS Code extension with a @unity chat participant for GitHub Copilot Chat.

Commands:

• @unity /status — Check connection to Unity Editor
• @unity /help — Show available commands and examples
• @unity /undo — Undo the last operation in Unity Editor
• @unity /redo — Redo the last undone operation
• @unity /history — Show the current undo group

Settings

Setting	Default	Description
unity-copilot.bridgePort	6400	WebSocket port the Unity bridge listens on
unity-copilot.autoConnect	true	Auto-connect when the extension activates

Requirements

• Unity 2022.3+ (any LTS)
• Node.js (for the MCP server)
• VS Code 1.90+ (optional, for the chat participant extension)

License

MIT