📌 The One Game Studio Fork
This is The One Game Studio's enhanced fork of the original MCP for Unity project.
We're extending it with studio-specific features for our production pipeline:

• 🧪 Automation Testing - Automated test execution and reporting within Unity
• 📦 Addressables Management - Full control over Unity Addressable Asset System
• 🚀 DOTS Implementation (Wishlist) - Unity Data-Oriented Technology Stack integration

Original project: https://github.com/CoplayDev/unity-mcp
Studio support: Contact The One Game Studio development team

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Originally sponsored and maintained by Coplay -- the best AI assistant for Unity. Read the backstory here.

Create your Unity apps with LLMs!

MCP for Unity acts as a bridge, allowing AI assistants (like Claude, Cursor) to interact directly with your Unity Editor via a local MCP (Model Context Protocol) Client. Give your LLM tools to manage assets, control scenes, edit scripts, and automate tasks within Unity.

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💬 Join Our Discord

Get help, share ideas, and collaborate with other MCP for Unity developers!

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Key Features 🚀

• 🗣️ Natural Language Control: Instruct your LLM to perform Unity tasks.
• 🛠️ Powerful Tools: Manage assets, scenes, materials, scripts, and editor functions.
• 🤖 Automation: Automate repetitive Unity workflows.
• 🧩 Extensible: Designed to work with various MCP Clients.

Available Tools

Your LLM can use functions like:

• read_console: Gets messages from or clears the console.
• manage_script: Manages C# scripts (create, read, update, delete).
• manage_editor: Controls and queries the editor's state and settings.
• manage_scene: Manages scenes (load, save, create, get hierarchy, etc.).
• manage_asset: Performs asset operations (import, create, modify, delete, etc.).
• manage_shader: Performs shader CRUD operations (create, read, modify, delete).
• manage_gameobject: Manages GameObjects: create, modify, delete, find, and component operations.
• execute_menu_item: Executes a menu item via its path (e.g., "File/Save Project").
• apply_text_edits: Precise text edits with precondition hashes and atomic multi-edit batches.
• script_apply_edits: Structured C# method/class edits (insert/replace/delete) with safer boundaries.
• validate_script: Fast validation (basic/standard) to catch syntax/structure issues before/after writes.

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How It Works

MCP for Unity connects your tools using two components:

1. MCP for Unity Bridge: A Unity package running inside the Editor. (Installed via Package Manager).
2. MCP for Unity Server: A Python server that runs locally, communicating between the Unity Bridge and your MCP Client. (Installed automatically by the package on first run or via Auto-Setup; manual setup is available as a fallback).

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Installation ⚙️

Prerequisites

• Python: Version 3.12 or newer. Download Python

• Unity Hub & Editor: Version 2021.3 LTS or newer. Download Unity

• uv (Python toolchain manager):

  # macOS / Linux
  curl -LsSf https://astral.sh/uv/install.sh | sh
  
  # Windows (PowerShell)
  winget install Astral.Sh.Uv
  
  # Docs: https://docs.astral.sh/uv/getting-started/installation/

• An MCP Client: : Claude Desktop | Claude Code | Cursor | Visual Studio Code Copilot | Windsurf | Others work with manual config

• [Optional] Roslyn for Advanced Script Validation

  For Strict validation level that catches undefined namespaces, types, and methods:

  Method 1: NuGet for Unity (Recommended)

  1. Install NuGetForUnity
  2. Go to Window > NuGet Package Manager
  3. Search for Microsoft.CodeAnalysis.CSharp and install the package
  4. Go to Player Settings > Scripting Define Symbols
  5. Add USE_ROSLYN
  6. Restart Unity

  Method 2: Manual DLL Installation

  1. Download Microsoft.CodeAnalysis.CSharp.dll and dependencies from NuGet
  2. Place DLLs in Assets/Plugins/ folder
  3. Ensure .NET compatibility settings are correct
  4. Add USE_ROSLYN to Scripting Define Symbols
  5. Restart Unity

  Note: Without Roslyn, script validation falls back to basic structural checks. Roslyn enables full C# compiler diagnostics with precise error reporting.

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🌟 Step 1: Install the Unity Package

To install 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/The1Studio/unity-mcp.git?path=/UnityMcpBridge
   
   **Original project**: https://github.com/CoplayDev/unity-mcp.git?path=/UnityMcpBridge
   

5. Click Add.
6. The MCP server is installed automatically by the package on first run or via Auto-Setup. If that fails, use Manual Configuration (below).

To install via OpenUPM

1. Install the OpenUPM CLI

2. Open a terminal (PowerShell, Terminal, etc.) and navigate to your Unity project directory

3. Run openupm add com.theonegamestudio.unity-mcp

   Note: This is The One Game Studio's fork. For the original package, use com.coplaydev.unity-mcp

Note: If you installed the MCP Server before Coplay's maintenance, you will need to uninstall the old package before re-installing the new one.

🛠️ Step 2: Configure Your MCP Client

Connect your MCP Client (Claude, Cursor, etc.) to the Python server set up in Step 1 (auto) or via Manual Configuration (below).

Option A: Auto-Setup (Recommended for Claude/Cursor/VSC Copilot)

1. In Unity, go to Window > MCP for Unity.
2. Click Auto-Setup.
3. Look for a green status indicator 🟢 and "Connected ✓". (This attempts to modify the MCP Client's config file automatically).

Client-specific troubleshooting

• VSCode: uses Code/User/mcp.json with top-level servers.unityMCP and "type": "stdio". On Windows, MCP for Unity writes an absolute uv.exe (prefers WinGet Links shim) to avoid PATH issues.
• Cursor / Windsurf (help link): if uv is missing, the MCP for Unity window shows "uv Not Found" with a quick [HELP] link and a "Choose uv Install Location" button.
• Claude Code (help link): if claude isn't found, the window shows "Claude Not Found" with [HELP] and a "Choose Claude Location" button. Unregister now updates the UI immediately.

Option B: Manual Configuration

If Auto-Setup fails or you use a different client:

1. Find your MCP Client's configuration file. (Check client documentation).
   • Claude Example (macOS): ~/Library/Application Support/Claude/claude_desktop_config.json
   • Claude Example (Windows): %APPDATA%\Claude\claude_desktop_config.json
2. Edit the file to add/update the mcpServers section, using the exact paths from Step 1.

Click for Client-Specific JSON Configuration Snippets...

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Claude Code

If you're using Claude Code, you can register the MCP server using the below commands: 🚨make sure to run these from your Unity project's home directory🚨

macOS:

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

Windows:

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

VSCode (all OS)

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

On Windows, set command to the absolute shim, e.g. C:\\Users\\YOU\\AppData\\Local\\Microsoft\\WinGet\\Links\\uv.exe.

Windows:

{
  "mcpServers": {
    "UnityMCP": {
      "command": "uv",
      "args": [
        "run",
        "--directory",
        "C:\\Users\\YOUR_USERNAME\\AppData\\Local\\UnityMCP\\UnityMcpServer\\src",
        "server.py"
      ]
    }
    // ... other servers might be here ...
  }
}

(Remember to replace YOUR_USERNAME and use double backslashes \)

macOS:

{
  "mcpServers": {
    "UnityMCP": {
      "command": "uv",
      "args": [
        "run",
        "--directory",
        "/Users/YOUR_USERNAME/Library/AppSupport/UnityMCP/UnityMcpServer/src",
        "server.py"
      ]
    }
    // ... other servers might be here ...
  }
}

(Replace YOUR_USERNAME. Note: AppSupport is a symlink to "Application Support" to avoid quoting issues)

Linux:

{
  "mcpServers": {
    "UnityMCP": {
      "command": "uv",
      "args": [
        "run",
        "--directory",
        "/home/YOUR_USERNAME/.local/share/UnityMCP/UnityMcpServer/src",
        "server.py"
      ]
    }
    // ... other servers might be here ...
  }
}

(Replace YOUR_USERNAME)

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Usage ▶️

1. Open your Unity Project. The MCP for Unity package should connect automatically. Check status via Window > MCP for Unity.

2. Start your MCP Client (Claude, Cursor, etc.). It should automatically launch the MCP for Unity Server (Python) using the configuration from Installation Step 2.

3. Interact! Unity tools should now be available in your MCP Client.

   Example Prompt: Create a 3D player controller, Create a tic-tac-toe game in 3D, Create a cool shader and apply to a cube.

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Development & Contributing 🛠️

For Developers

If you're contributing to MCP for Unity or want to test core changes, we have development tools to streamline your workflow:

• Development Deployment Scripts: Quickly deploy and test your changes to MCP for Unity Bridge and Python Server
• Automatic Backup System: Safe testing with easy rollback capabilities
• Hot Reload Workflow: Fast iteration cycle for core development

📖 See README-DEV.md for complete development setup and workflow documentation.

Contributing 🤝

Help make MCP for Unity better!

1. Fork the main repository.
2. Create a branch (feature/your-idea or bugfix/your-fix).
3. Make changes.
4. Commit (feat: Add cool new feature).
5. Push your branch.
6. Open a Pull Request against the main branch.

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Troubleshooting ❓

Click to view common issues and fixes...

• Unity Bridge Not Running/Connecting:
  • Ensure Unity Editor is open.
  • Check the status window: Window > MCP for Unity.
  • Restart Unity.
• MCP Client Not Connecting / Server Not Starting:
  • Verify Server Path: Double-check the --directory path in your MCP Client's JSON config. It must exactly match the installation location:
    • Windows: %USERPROFILE%\AppData\Local\UnityMCP\UnityMcpServer\src
    • macOS: ~/Library/AppSupport/UnityMCP/UnityMcpServer\src
    • Linux: ~/.local/share/UnityMCP/UnityMcpServer\src
  • Verify uv: Make sure uv is installed and working (uv --version).
  • Run Manually: Try running the server directly from the terminal to see errors:

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

• Auto-Configure Failed:
  • Use the Manual Configuration steps. Auto-configure might lack permissions to write to the MCP client's config file.
• Running Multiple Unity Projects:
  • If you need to run multiple Unity projects with MCP simultaneously, configure different ports to avoid conflicts
  • Default port is 6400; use Window > MCP for Unity > Settings to change port
  • Test projects like TestProjects/UnityMCPTests use port 6401
  • Update your MCP client configuration with the matching port number

Still stuck? Open an Issue or Join the Discord!

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License 📜

MIT License. See LICENSE file.

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