Content
<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.
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[](https://www.coplay.dev/?ref=unity-mcp)
[](https://unity.com/releases/editor/archive)
[](https://www.python.org)
[](https://modelcontextprotocol.io/introduction)
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**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:
* `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").
* `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_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.
* `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 fixed version?** Use a tagged URL instead (updates require uninstalling and re-installing):
```
https://github.com/CoplayDev/unity-mcp.git?path=/MCPForUnity#v8.0.0
```
#### 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).
**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 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.
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