Unity MCP 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.
3. Search for `Microsoft.CodeAnalysis.CSharp` and install the package
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>
If you're using Claude Code, you can register the MCP server using these commands:
**macOS:**
```bash
claude mcp add UnityMCP -- uv --directory /[PATH_TO]/UnityMCP/UnityMcpServer/src run server.py
```
**Windows:**
```bash
claude mcp add UnityMCP -- "C:/Users/USERNAME/AppData/Roaming/Python/Python313/Scripts/uv.exe" --directory "C:/Users/USERNAME/AppData/Local/Programs/UnityMCP/UnityMcpServer/src" run server.py
1.**Open your Unity Project.** The Unity MCP Bridge (package) should connect automatically. Check status via Window > Unity MCP.
2.**Start your MCP Client** (Claude, Cursor, etc.). It should automatically launch the Unity MCP Server (Python) using the configuration from Installation Step 3.
3.**Interact!** Unity tools should now be available in your MCP Client.
- [x]**Advanced Script Validation** - Multi-level validation with semantic analysis, namespace/type checking, and Unity best practices (Will need Roslyn Installed, see [Prerequisite](#prerequisites)).
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 master branch.
---
## 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 > Unity MCP.
- 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 location where you cloned the UnityMCP repository in Installation Step 1 (e.g., .../Programs/UnityMCP/UnityMcpServer/src).
- **Verify uv:** Make sure uv is installed and working (pip show uv).
- **Run Manually:** Try running the server directly from the terminal to see errors: `# Navigate to the src directory first! cd /path/to/your/UnityMCP/UnityMcpServer/src uv run server.py`
- **Permissions (macOS/Linux):** If you installed the server in a system location like /usr/local/bin, ensure the user running the MCP client has permission to execute uv and access files there. Installing in ~/bin might be easier.
- **Auto-Configure Failed:**
- Use the Manual Configuration steps. Auto-configure might lack permissions to write to the MCP client's config file.
Still stuck? [Open an Issue](https://www.google.com/url?sa=E&q=https%3A%2F%2Fgithub.com%2Fjustinpbarnett%2Funity-mcp%2Fissues) or [Join the Discord](https://discord.gg/vhTUxXaqYr)!
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