Unity MCP server

MCP for Unity is a powerful bridge that allows AI assistants like Claude and Cursor to interact directly with your Unity Editor through the Model Context Protocol (MCP). This tool enables your LLM to perform Unity tasks through natural language commands, giving it the ability to manage assets, control scenes, edit scripts, and automate workflows.

Installation

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, VS Code Copilot, or Windsurf

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
   

5. Click Add

Via OpenUPM

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

Step 2: 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

If Auto-Setup fails, find your MCP Client's configuration file and add the MCP server configuration manually:

For Claude Code:

MacOS:

claude mcp add --scope user UnityMCP -- uv --directory /Users/USERNAME/Library/AppSupport/UnityMCP/UnityMcpServer/src run server.py

Windows:

claude mcp add --scope user UnityMCP -- "C:/Users/USERNAME/AppData/Local/Microsoft/WinGet/Links/uv.exe" --directory "C:/Users/USERNAME/AppData/Local/UnityMCP/UnityMcpServer/src" run server.py

For VSCode (all OS):

{
  "servers": {
    "unityMCP": {
      "command": "uv",
      "args": ["--directory","<ABSOLUTE_PATH_TO>/UnityMcpServer/src","run","server.py"],
      "type": "stdio"
    }
  }
}

Usage

1. Open your Unity Project. The MCP for Unity package should connect automatically.

2. Start your MCP Client (Claude, Cursor, etc.). It will automatically launch the MCP for Unity Server.

3. Interact with Unity through your MCP Client using natural language:

   • "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

MCP for Unity supports multiple Unity Editor instances simultaneously:

1. List available instances by asking your LLM to check the unity_instances resource

2. Set the active instance with set_active_instance and the instance name (e.g., MyProject@abc123)

3. All subsequent tools route to that instance until changed

Example:

User: "List all Unity instances"
LLM: [Shows ProjectA@abc123 and ProjectB@def456]

User: "Set active instance to ProjectA@abc123"
LLM: [Calls set_active_instance("ProjectA@abc123")]

User: "Create a red cube"
LLM: [Creates cube in ProjectA]

Troubleshooting

If Unity Bridge isn't connecting:

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

If MCP Client isn't connecting or server isn't starting:

• Verify the server path in your MCP Client's JSON config matches the installation location
• Make sure 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
  

If configuration failed, use the Manual Configuration steps as the plugin may lack permissions to write to the MCP client's config file.

For further assistance, join the community on Discord.

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