unity-mcp

<img width="676" height="380" alt="MCP for Unity" src="docs/images/logo.png" /> | [English](README.md) | [简体中文](README-zh.md) | |----------------------|---------------------------------| #### Proudly sponsored and maintained by [Coplay](https://www.coplay.dev/?ref=unity-mcp) -- the best AI assistant for Unity. [](https://discord.gg/y4p8KfzrN4) [](https://www.coplay.dev/?ref=unity-mcp) [](https://unity.com/releases/editor/archive) [](https://www.python.org) [](https://modelcontextprotocol.io/introduction)   [](https://opensource.org/licenses/MIT) **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. <img width="406" height="704" alt="MCP for Unity screenshot" src="docs/images/readme_ui.png"> --- ### 💬 Join Our [Discord](https://discord.gg/y4p8KfzrN4) **Get help, share ideas, and collaborate with other MCP for Unity developers!** --- ## 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. * **🌐 HTTP-First Transport:** Ships with HTTP connections enabled by default (stdio is still available as a fallback). <details open> <summary><strong>Tools</strong></summary> Your LLM can use functions like: * `manage_asset`: Performs asset operations (import, create, modify, delete, etc.). * `manage_editor`: Controls and queries the editor's state and settings. * `manage_gameobject`: Manages GameObjects: create, modify, delete, find, and component operations. * `manage_material`: Manages materials: create, set properties, colors, assign to renderers, and query material info. * `manage_prefabs`: Performs prefab operations (create, modify, delete, etc.). * `manage_scene`: Manages scenes (load, save, create, get hierarchy, etc.). * `manage_script`: Compatibility router for legacy script operations (create, read, delete). Prefer `apply_text_edits` or `script_apply_edits` for edits. * `manage_shader`: Performs shader CRUD operations (create, read, modify, delete). * `read_console`: Gets messages from or clears the console. * `run_tests`: Runs tests in the Unity Editor. * `execute_custom_tool`: Execute a project-scoped custom tool registered by Unity. * `execute_menu_item`: Executes Unity Editor menu items (e.g., "File/Save Project"). * `set_active_instance`: Routes subsequent tool calls to a specific Unity instance (when multiple are running). Requires the exact `Name@hash` from `unity_instances`. * `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. * `create_script`: Create a new C# script at the given project path. * `delete_script`: Delete a C# script by URI or Assets-relative path. * `get_sha`: Get SHA256 and basic metadata for a Unity C# script without returning file contents. </details> <details open> <summary><strong>Resources</strong></summary> Your LLM can retrieve the following resources: * `custom_tools`: Lists custom tools available for the active Unity project. * `unity_instances`: Lists all running Unity Editor instances with their details (name, path, port, status). * `menu_items`: Retrieves all available menu items in the Unity Editor. * `tests`: Retrieves all available tests in the Unity Editor. Can select tests of a specific type (e.g., "EditMode", "PlayMode"). * `editor_active_tool`: Currently active editor tool (Move, Rotate, Scale, etc.) and transform handle settings. * `editor_prefab_stage`: Current prefab editing context if a prefab is open in isolation mode. * `editor_selection`: Detailed information about currently selected objects in the editor. * `editor_state`: Current editor runtime state including play mode, compilation status, active scene, and selection summary. * `editor_windows`: All currently open editor windows with their titles, types, positions, and focus state. * `project_info`: Static project information including root path, Unity version, and platform. * `project_layers`: All layers defined in the project's TagManager with their indices (0-31). * `project_tags`: All tags defined in the project's TagManager. </details> --- ## 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 (from a terminal window) and speaks HTTP/JSON-RPC to your MCP client. The Unity window launches it for you in HTTP mode by default; stdio is still available if you switch transports. <img width="562" height="121" alt="image" src="https://github.com/user-attachments/assets/9abf9c66-70d1-4b82-9587-658e0d45dc3e" /> --- ## Installation ⚙️ ### Prerequisites * **Python:** Version 3.10 or newer. [Download Python](https://www.python.org/downloads/) * **Unity Hub & Editor:** Version 2021.3 LTS or newer. [Download Unity](https://unity.com/download) * **uv (Python toolchain manager):** ```bash # macOS / Linux curl -LsSf https://astral.sh/uv/install.sh | sh # Windows (PowerShell) winget install --id=astral-sh.uv -e # Docs: https://docs.astral.sh/uv/getting-started/installation/ ``` * **An MCP Client:** : [Claude Desktop](https://claude.ai/download) | [Claude Code](https://github.com/anthropics/claude-code) | [Cursor](https://www.cursor.com/en/downloads) | [Visual Studio Code Copilot](https://code.visualstudio.com/docs/copilot/overview) | [Windsurf](https://windsurf.com) | Others work with manual config * <details> <summary><strong>[Optional] Roslyn for Advanced Script Validation</strong></summary> For **Strict** validation level that catches undefined namespaces, types, and methods: **Method 1: NuGet for Unity (Recommended)** 1. Install [NuGetForUnity](https://github.com/GlitchEnzo/NuGetForUnity) 2. Go to `Window > NuGet Package Manager` 3. Search for `Microsoft.CodeAnalysis`, select version 4.14.0, and install the package 4. Also install package `SQLitePCLRaw.core` and `SQLitePCLRaw.bundle_e_sqlite3`. 5. Go to `Player Settings > Scripting Define Symbols` 6. Add `USE_ROSLYN` 7. Restart Unity **Method 2: Manual DLL Installation** 1. Download Microsoft.CodeAnalysis.CSharp.dll and dependencies from [NuGet](https://www.nuget.org/packages/Microsoft.CodeAnalysis.CSharp/) 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.</details> --- ### 🌟 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/CoplayDev/unity-mcp.git?path=/MCPForUnity ``` 5. Click `Add`. **Need a stable/fixed version?** Use a tagged URL instead (updates require uninstalling and re-installing): ``` https://github.com/CoplayDev/unity-mcp.git?path=/MCPForUnity#v8.2.1 ``` #### To install via OpenUPM 1. Install the [OpenUPM CLI](https://openupm.com/docs/getting-started-cli.html) 2. Open a terminal (PowerShell, Terminal, etc.) and navigate to your Unity project directory 3. Run `openupm add 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: Start the Local HTTP Server (Default) HTTP transport is enabled out of the box. The Unity window can launch the FastMCP server for you: 1. Open `Window > MCP for Unity`. 2. Make sure the **Transport** dropdown is set to `HTTP` (default) and the **HTTP URL** is what you want (defaults to `http://localhost:8080`). 3. Click **Start Local HTTP Server**. Unity spawns a new operating-system terminal running `uv ... server.py --transport http`. 4. Keep that terminal window open while you work; closing it stops the server. Use the **Stop Session** button in the Unity window if you need to tear it down cleanly. > Prefer stdio? Change the transport dropdown to `Stdio` and Unity will fall back to the embedded TCP bridge instead of launching the HTTP server. **Manual launch (optional)** You can also start the server yourself from a terminal—useful for CI or when you want to see raw logs: ```bash uvx --from "git+https://github.com/CoplayDev/unity-mcp@v8.1.0#subdirectory=Server" mcp-for-unity --transport http --http-url http://localhost:8080 ``` Keep the process running while clients are connected. ### 🛠️ Step 3: Configure Your MCP Client Connect your MCP Client (Claude, Cursor, etc.) to the HTTP server from Step 2 (auto) or via Manual Configuration (below). For **Claude Desktop** Users, try using our manually scrapped Unity_Skills by downloading and uploading the claude_skill_unity.zip following this [link](https://www.claude.com/blog/skills). **Option A: Configure Buttons (Recommended for Claude/Cursor/VSC Copilot)** 1. In Unity, go to `Window > MCP for Unity`. 2. Select your Client/IDE from the dropdown. 3. Click the `Configure` Button. (Or the `Configure All Detected Clients` button will try to configure every client it finds, but takes longer.) 4. Look for a green status indicator 🟢 and "Connected ✓". *(This writes the HTTP `url` pointing at the server you launched in Step 2.)* <details><summary><strong>Client-specific troubleshooting</strong></summary> - **VSCode**: uses `Code/User/mcp.json` with top-level `servers.unityMCP`, `"type": "http"`, and the URL from Step 2. On Windows, MCP for Unity still prefers an absolute `uv.exe` path when you switch back to stdio. - **Cursor / Windsurf** [(**help link**)](https://github.com/CoplayDev/unity-mcp/wiki/1.-Fix-Unity-MCP-and-Cursor,-VSCode-&-Windsurf): 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**)](https://github.com/CoplayDev/unity-mcp/wiki/2.-Fix-Unity-MCP-and-Claude-Code): 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.</details> **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 so it points at the HTTP endpoint from Step 2. <details> <summary><strong>Click for Client-Specific JSON Configuration Snippets...</strong></summary> --- **Claude Code** If you're using Claude Code, you can register the MCP server using the below commands: **macOS:** ```bash claude mcp add --scope user UnityMCP -- uv --directory /Users/USERNAME/Library/AppSupport/UnityMCP/UnityMcpServer/src run server.py ``` **Windows:** ```bash 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 ``` **VSCode (all OS – HTTP default)** ```json { "servers": { "unityMCP": { "type": "http", "url": "http://localhost:8080/mcp" } } } ``` **macOS / Windows / Linux (Claude Desktop, Cursor, Claude Code, Windsurf, etc. – HTTP default)** ```json { "mcpServers": { "unityMCP": { "url": "http://localhost:8080/mcp" } } } ``` Set the URL to match whatever you entered in the Unity window (include `/mcp`). #### Stdio configuration examples (legacy / optional) Switch the Unity transport dropdown to `Stdio`, then use one of the following `command`/`args` blocks. **VSCode (stdio)** ```json { "servers": { "unityMCP": { "type": "stdio", "command": "uv", "args": [ "--directory", "<ABSOLUTE_PATH_TO>/UnityMcpServer/src", "run", "server.py", "--transport", "stdio" ] } } } ``` **macOS / Linux (stdio)** ```json { "mcpServers": { "unityMCP": { "command": "uv", "args": [ "run", "--directory", "/Users/YOUR_USERNAME/Library/AppSupport/UnityMCP/UnityMcpServer/src", "server.py", "--transport", "stdio" ] } } } ``` **Windows (stdio)** ```json { "mcpServers": { "unityMCP": { "command": "C:/Users/YOUR_USERNAME/AppData/Local/Microsoft/WinGet/Links/uv.exe", "args": [ "run", "--directory", "C:/Users/YOUR_USERNAME/AppData/Local/UnityMCP/UnityMcpServer/src", "server.py", "--transport", "stdio" ] } } } ``` Replace `YOUR_USERNAME` and `AppSupport` path segments as needed for your platform. </details> --- ## Usage ▶️ 1. **Open your Unity Project** and verify the HTTP server is running (Window > MCP for Unity > Start Local HTTP Server). The indicator should show "Session Active" once the server is up. 2. **Start your MCP Client** (Claude, Cursor, etc.). It connects to the HTTP endpoint configured in Step 3—no extra terminals will be spawned by the client. 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`. ### Working with Multiple Unity Instances MCP for Unity supports multiple Unity Editor instances simultaneously. Each instance is isolated per MCP client session. **To direct tool calls to a specific instance:** 1. List available instances: Ask your LLM to check the `unity_instances` resource 2. Set the active instance: Use `set_active_instance` with the exact `Name@hash` shown (e.g., `MyProject@abc123`) 3. All subsequent tools route to that instance until changed. If multiple instances are running and no active instance is set, the server will error and instruct you to select one. **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] ``` --- ## Development & Contributing 🛠️ ### Development Setup and Guidelines See [README-DEV.md](docs/README-DEV.md) for complete development setup and workflow documentation. ### Adding Custom Tools MCP for Unity uses a Python MCP Server tied with Unity's C# scripts for tools. If you'd like to extend the functionality with your own tools, learn how to do so in **[CUSTOM_TOOLS.md](docs/CUSTOM_TOOLS.md)**. ### How to Contribute 1. **Fork** the main repository. 2. **Create an issue** to discuss your idea or bug. 3. **Create a branch** (`feature/your-idea` or `bugfix/your-fix`). 4. **Make changes.** 5. **Commit** (feat: Add cool new feature). 6. **Push** your branch. 7. **Open a Pull Request** against the main branch, referencing the issue you created earlier. --- ## 📊 Telemetry & Privacy MCP for Unity includes **privacy-focused, anonymous telemetry** to help us improve the product. We collect usage analytics and performance data, but **never** your code, project names, or personal information. - **🔒 Anonymous**: Random UUIDs only, no personal data - **🚫 Easy opt-out**: Set `DISABLE_TELEMETRY=true` environment variable - **📖 Transparent**: See [TELEMETRY.md](docs/TELEMETRY.md) for full details Your privacy matters to us. All telemetry is optional and designed to respect your workflow. --- ## Troubleshooting ❓ <details> <summary><strong>Click to view common issues and fixes...</strong></summary> - **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:** - Make sure the local HTTP server is running (Window > MCP for Unity > Start Local HTTP Server). Keep the spawned terminal window open. - **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: ```bash cd /path/to/your/UnityMCP/UnityMcpServer/src uv run server.py ``` - **Configuration Failed:** - Use the Manual Configuration steps. The plugin may lack permissions to write to the MCP client's config file. </details> Still stuck? [Open an Issue](https://github.com/CoplayDev/unity-mcp/issues) or [Join the Discord](https://discord.gg/y4p8KfzrN4)! --- ## License 📜 MIT License. See [LICENSE](LICENSE) file. --- ## Star History [](https://www.star-history.com/#CoplayDev/unity-mcp&Date) ## Unity AI Tools by Coplay Coplay offers 2 AI tools for Unity - **MCP for Unity** is available freely under the MIT license. - **Coplay** is a premium Unity AI assistant that sits within Unity and is more than the MCP for Unity. (These tools have different tech stacks. See this blog post [comparing Coplay to MCP for Unity](https://www.coplay.dev/blog/comparing-coplay-and-unity-mcp).) <img alt="Coplay" src="docs/images/coplay-logo.png" /> ## Disclaimer This project is a free and open-source tool for the Unity Editor, and is not affiliated with Unity Technologies.