MCP For Unity

from mcp.server.fastmcp import FastMCP import asyncio import websockets import json # Initialize the MCP Server mcp = FastMCP("UnityMCP") UNITY_WS_URL = "ws://localhost:8080" async def send_ws_command(method: str, **kwargs) -> str: """Helper to send WebSocket commands to Unity.""" payload = { "method": method, # Flatten params for simple Unity JsonUtility parsing "param_name": kwargs.get("name", ""), "param_string": kwargs.get("string_param", ""), "param_second": kwargs.get("second_param", ""), "param_value": kwargs.get("value_param", ""), "param_pos": kwargs.get("position", None), "param_rot": kwargs.get("rotation", None), "param_scale": kwargs.get("scale", None) } try: async with websockets.connect(UNITY_WS_URL) as websocket: await websocket.send(json.dumps(payload)) response = await websocket.recv() # Parse response data = json.loads(response) if data.get("status") == "success": return data.get("result", "Success") else: return f"Error: {data.get('message')}" except ConnectionRefusedError: return "Could not connect to Unity. Is the project open?" except Exception as e: return f"WebSocket Error: {str(e)}" @mcp.tool() async def ping_unity() -> str: """Checks if the Unity Editor is connected via WebSocket.""" # Simple HTTP ping fallback is still available in Unity server, but let's try WS try: async with websockets.connect(UNITY_WS_URL) as websocket: return "Connected to Unity WebSocket Server!" except: return "Failed to connect to Unity." @mcp.tool() async def create_game_object(name: str, position_x: float = 0, position_y: float = 0, position_z: float = 0) -> str: """Creates a new GameObject in the Unity Scene.""" return await send_ws_command("CreateObject", name=name, position={"x": position_x, "y": position_y, "z": position_z}) @mcp.tool() async def delete_object(name: str) -> str: """Deletes a GameObject by name.""" return await send_ws_command("DeleteObject", name=name) @mcp.tool() async def add_component(object_name: str, component_name: str) -> str: """Adds a component to a GameObject. (e.g. Rigidbody, BoxCollider)""" return await send_ws_command("AddComponent", name=object_name, string_param=component_name) @mcp.tool() async def find_object(name: str) -> str: """Finds a GameObject and returns its details (Transform, Components).""" return await send_ws_command("FindObject", name=name) @mcp.tool() async def modify_transform(name: str, pos_x: float = None, pos_y: float = None, pos_z: float = None, rot_x: float = None, rot_y: float = None, rot_z: float = None, scale_x: float = None, scale_y: float = None, scale_z: float = None) -> str: """Modifies the transform (Position, Rotation, Scale) of a GameObject.""" pos = {"x": pos_x, "y": pos_y, "z": pos_z} if pos_x is not None else None rot = {"x": rot_x, "y": rot_y, "z": rot_z} if rot_x is not None else None scale = {"x": scale_x, "y": scale_y, "z": scale_z} if scale_x is not None else None return await send_ws_command("ModifyTransform", name=name, position=pos, rotation=rot, scale=scale) @mcp.tool() async def get_hierarchy() -> str: """Gets the current scene hierarchy.""" return await send_ws_command("GetHierarchy") @mcp.tool() async def create_script(script_name: str, content: str) -> str: """Creates a new C# script in Assets/Scripts/Generated. Args: script_name: Name of the class/file (e.g. 'MyScript') content: The full C# code content. """ return await send_ws_command("CreateScript", name=script_name, string_param=content) @mcp.tool() async def create_material(material_name: str, r: float = 1, g: float = 1, b: float = 1) -> str: """Creates a new Material in Assets/Materials/Generated with a specific color.""" return await send_ws_command("CreateMaterial", name=material_name, position={"x":r, "y":g, "z":b}) @mcp.tool() async def list_assets(path: str = "Assets") -> str: """Lists files and directories in the project.""" return await send_ws_command("ListAssets", string_param=path) @mcp.tool() async def read_console() -> str: """Reads the last 100 log messages from the Unity Console.""" return await send_ws_command("ReadConsole") @mcp.tool() async def set_play_mode(active: bool) -> str: """Enables or disables Play Mode in the Unity Editor.""" return await send_ws_command("SetPlayMode", string_param=str(active).lower()) @mcp.tool() async def execute_menu_item(menu_path: str) -> str: """Executes a Unity Editor menu item (e.g. 'Assets/Refresh', 'Window/General/Game').""" return await send_ws_command("ExecuteMenuItem", string_param=menu_path) @mcp.tool() async def is_compiling() -> str: """Checks if the Unity Editor is currently compiling scripts.""" return await send_ws_command("IsCompiling") @mcp.tool() async def get_selection() -> str: """Gets the name of the currently selected GameObject in the Editor.""" return await send_ws_command("GetSelection") @mcp.tool() async def set_selection(name: str) -> str: """Selects a GameObject in the Editor by name.""" return await send_ws_command("SetSelection", name=name) @mcp.tool() async def inspect_object(name: str) -> str: """Inspects a GameObject, listing all components and their public fields/properties.""" return await send_ws_command("InspectObject", name=name) @mcp.tool() async def get_screenshot() -> str: """Captures a screenshot from the Main Camera and returns it as a Base64 encoded JPG string. Useful for 'seeing' the current state of the scene. """ return await send_ws_command("GetScreenshot") @mcp.tool() async def set_component_property(object_name: str, component_name: str, property_name: str, value: str) -> str: """Sets a property or field value on a component. Args: object_name: Name of the GameObject. component_name: Name of the Component (e.g. 'Light', 'Rigidbody'). property_name: Name of the field/property (e.g. 'color', 'mass', 'intensity'). value: The new value as a string (e.g. '10', '5.5', 'true'). """ return await send_ws_command("SetComponentProperty", name=object_name, string_param=component_name, second_param=property_name, value_param=value) if __name__ == "__main__": # Run as SSE server for better compatibility with VS Code / Cursor mcp.run(transport="sse")