Unity MCP server

MCP for Unity serves as a bridge that allows AI assistants like Claude or Cursor to interact directly with your Unity Editor through a local MCP (Model Context Protocol) Client, enabling them to manage assets, control scenes, edit scripts, and automate tasks within Unity.

Getting Started

Prerequisites

• Python 3.10 or newer
• Unity Hub & Editor (version 2021.3 LTS or newer)
• uv (Python toolchain manager)

  # macOS / Linux
  curl -LsSf https://astral.sh/uv/install.sh | sh
  
  # Windows (PowerShell)
  winget install --id=astral-sh.uv -e
  

• An MCP Client: Claude Desktop, Claude Code, Cursor, Visual Studio Code Copilot, Windsurf, or others

Installation

Step 1: Install the Unity Package

Via Git URL

1. Open your Unity project
2. Go to Window > Package Manager
3. Click + -> Add package from git URL...
4. Enter:

   https://github.com/CoplayDev/unity-mcp.git?path=/MCPForUnity#v8.0.1
   

5. Click Add

Via OpenUPM

1. Install the OpenUPM CLI
2. Navigate to your Unity project directory in a terminal
3. Run openupm add com.coplaydev.unity-mcp

Step 2: Start the Local HTTP Server

1. In Unity, open Window > MCP for Unity
2. Ensure the Transport dropdown is set to HTTP (default)
3. Verify the HTTP URL is correct (defaults to http://localhost:8080)
4. Click Start Local HTTP Server
5. Keep the spawned terminal window open while working

You can also start the server manually from a terminal:

uvx --from "git+https://github.com/CoplayDev/[email protected]#subdirectory=Server" mcp-for-unity --transport http --http-url http://localhost:8080

Step 3: Configure Your MCP Client

Option A: Auto-Setup (Recommended)

1. In Unity, go to Window > MCP for Unity
2. Click Auto-Setup
3. Look for a green status indicator 🟢 and "Connected ✓"

Option B: Manual Configuration

1. Find your MCP Client's configuration file

2. Add/update the mcpServers section to point to the HTTP endpoint from Step 2

   For HTTP configuration (recommended):

   {
     "mcpServers": {
       "UnityMCP": {
         "url": "http://localhost:8080/mcp"
       }
     }
   }
   

Usage

1. Open your Unity Project and verify the HTTP server is running. The indicator in Window > MCP for Unity should show "Session Active".

2. Start your MCP Client (Claude, Cursor, etc.)

3. Interact with Unity through your AI assistant

   Example prompts:

   • "Create a 3D player controller"
   • "Create a tic-tac-toe game in 3D"
   • "Create a cool shader and apply to a cube"

Working with Multiple Unity Instances

If you have multiple Unity instances open:

1. Ask your LLM to check the unity_instances resource to list available instances
2. Use set_active_instance with the exact Name@hash shown (e.g., MyProject@abc123)
3. All subsequent tools will route to that instance until changed

Troubleshooting

Unity Bridge Not Running/Connecting

• Ensure Unity Editor is open
• Check the status window: Window > MCP for Unity
• Restart Unity if needed

MCP Client Not Connecting / Server Not Starting

• Make sure the local HTTP server is running
• Verify the server path in your MCP Client's config
• Confirm uv is installed and working (uv --version)
• Try running the server directly from terminal to see errors:

  cd /path/to/your/UnityMCP/UnityMcpServer/src
  uv run server.py
  

Configuration Failed

• Use Manual Configuration if auto-setup lacks permission to write to config files

For more help, join the Discord community.

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "unityMCP" '{"command":"uv","args":["--directory","/path/to/your/unity-mcp/Python","run","server.py"]}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "unityMCP": {
            "command": "uv",
            "args": [
                "--directory",
                "/path/to/your/unity-mcp/Python",
                "run",
                "server.py"
            ]
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "unityMCP": {
            "command": "uv",
            "args": [
                "--directory",
                "/path/to/your/unity-mcp/Python",
                "run",
                "server.py"
            ]
        }
    }
}

3. Restart Claude Desktop for the changes to take effect