Unity MCP server

The Unity MCP server allows your Unity projects to communicate with AI language models using the Model Context Protocol (MCP). This server acts as a bridge between Unity and various AI assistants like Claude, Cursor, and Windsurf.

Installation

To use the MCP server with your Unity project, you need to install both the Unity MCP Plugin and an MCP client.

Step 1: Install Unity MCP Server

You can run the MCP server in several ways, with Docker being the simplest option:

docker run -p 8080:8080 ivanmurzakdev/unity-mcp-server

For STDIO transport (where the MCP client launches the server):

docker run -t -e UNITY_MCP_CLIENT_TRANSPORT=stdio -p 8080:8080 ivanmurzakdev/unity-mcp-server

If you need a custom port:

docker run -e UNITY_MCP_PORT=123 -p 123:123 ivanmurzakdev/unity-mcp-server

Step 2: Configure MCP Client

For HTTP transport, configure your MCP client with:

{
  "mcpServers": {
    "Unity-MCP": {
      "url": "http://localhost:8080"
    }
  }
}

For STDIO transport:

{
  "mcpServers": {
    "Unity-MCP": {
      "command": "docker",
      "args": [
        "run",
        "-t",
        "-e",
        "UNITY_MCP_CLIENT_TRANSPORT=stdio",
        "-p",
        "8080:8080",
        "ivanmurzakdev/unity-mcp-server"
      ]
    }
  }
}

Command Line Arguments

The server supports several configuration options:

Parameter	Description	Default Value
--port	Server port for connections	8080
--plugin-timeout	Plugin connection timeout in ms	10000
--client-transport	Transport type (stdio or http)	http

You can specify these as either environment variables or command-line arguments:

./unity-mcp-server --port 8080 --plugin-timeout 10000 --client-transport stdio

Using Binary Executables

Instead of Docker, you can use pre-compiled binary files specific to your CPU architecture. These are available on the GitHub Release Page.

./unity-mcp-server --port 8080 --plugin-timeout 10000 --client-transport stdio

Running in a Unity Project

When used in a Unity project, the MCP server facilitates communication between your game/application and AI language models. This enables features like AI-powered debugging, dynamic NPC behavior, and runtime AI assistance.

To connect to the server from your Unity code:

UnityMcpPlugin.BuildAndStart(); // Initialize the plugin
UnityMcpPlugin.Connect(); // Connect to the MCP server
// Later when needed:
UnityMcpPlugin.Disconnect(); // Disconnect from the server

The MCP server architecture provides a flexible foundation for integrating AI capabilities into your Unity projects, whether during development or at runtime in your final application.

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 "unity-mcp" '{"command":"dotnet","args":["run","--project","path/to/unity-mcp"]}'

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": {
        "unity-mcp": {
            "command": "dotnet",
            "args": [
                "run",
                "--project",
                "path/to/unity-mcp"
            ]
        }
    }
}

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": {
        "unity-mcp": {
            "command": "dotnet",
            "args": [
                "run",
                "--project",
                "path/to/unity-mcp"
            ]
        }
    }
}

3. Restart Claude Desktop for the changes to take effect