Unity MCP server

The Unity MCP server provides an interface for AI assistants to interact directly with your Unity projects. It enables AI models to perform tasks like creating objects, modifying assets, and writing code within the Unity environment.

Installation

Step 1: Install the Unity Plugin

The Unity MCP server requires a plugin component to be installed in your Unity project:

1. Import the plugin package into your Unity project using one of these methods:
   • Double-click the installer package after downloading
   • In Unity, use Assets → Import Package → Custom Package and select the file

Step 2: Configure Your MCP Client

You can set up your MCP client either automatically or manually:

Automatic Configuration

1. Open your Unity project
2. Navigate to Window → AI Connector (Unity-MCP)
3. Click the "Configure" button next to your preferred MCP client

Manual Configuration

If automatic configuration doesn't work, you can manually set up your MCP client using the JSON configuration from the AI Connector window.

Using the MCP Server

Once installed, you can interact with your Unity project through your AI assistant by:

1. Opening your MCP client (Claude Code, Claude Desktop, GitHub Copilot, Cursor, etc.)
2. Enabling "Agent mode" if your client has this option
3. Describing tasks you want to accomplish, such as:

Explain my scene hierarchy

Create 3 cubes in a circle with radius 2

Create metallic golden material and attach it to a sphere gameObject

The AI will interpret your requests and use the available tools to execute them in your Unity project.

Advanced Configuration

Server Launch Options

The Unity-MCP server supports various launch configurations:

• Different transport protocols (HTTP and STDIO)
• Docker deployment options
• Custom configuration parameters

Adding Custom Tools

You can extend the MCP server's capabilities by creating custom tools:

[McpPluginToolType]
public class Tool_GameObject
{
    [McpPluginTool
    (
        "MyCustomTask",
        Title = "Create a new GameObject"
    )]
    [Description("Explain here to LLM what is this, when it should be called.")]
    public string CustomTask
    (
        [Description("Explain to LLM what is this.")]
        string inputData
    )
    {
        // Background thread code here

        return MainThread.Instance.Run(() =>
        {
            // Main thread Unity API code here
            return "[Success] Operation completed.";
        });
    }
}

Requirements

Important: Your project path cannot contain spaces:

• ✅ C:/MyProjects/Project
• ❌ C:/My Projects/Project

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