Unity MCP Server

What is Unity MCP Server?

Unity MCP Server (MCP for Unity) is a free, MIT-licensed unity mcp bridge that lets AI assistants such as Claude, Cursor, VS Code and Codex control the Unity Editor to manage assets, build scenes, edit C# scripts and run tests.

The project is maintained by CoplayDev and sponsored by Aura. It started as justinpbarnett/unity-mcp, which now redirects to CoplayDev/unity-mcp. It is a community project and is not affiliated with Unity Technologies. The README describes 50 focused MCP tool entry points, and it works with any MCP client.

How to use Unity MCP Server?

Prerequisites: Unity 2021.3 LTS through 6.x, Python 3.10+ with uv, git on your PATH (for the Git URL install), and an MCP client. No API key is needed for the core tools.

1. Install the Unity package. In Unity, open Window → Package Manager, click +, choose "Add package from git URL..." and paste:

https://github.com/CoplayDev/unity-mcp.git?path=/MCPForUnity#main

You can also install it from OpenUPM or the Unity Asset Store:

openupm add com.coplaydev.unity-mcp

2. Run the setup wizard. After import, a wizard checks Python and uv, then lists the MCP clients it detects. Pick them and click Configure Selected. You can return later via Window → MCP for Unity → Configure All Detected Clients. It is safe to re-run.
3. Prompt. Try "Create a cube at the origin and add a Rigidbody." The status panel reads Connected when everything is wired up.

By default the unity mcp server runs over HTTP on localhost:8080. Stdio is also available.

Claude Code

Claude Code is auto-configured over HTTP. To add it by hand:

claude mcp add --transport http UnityMCP http://localhost:8080/mcp

If you switch between HTTP and stdio in the MCP for Unity window, restart Claude Code.

Claude Desktop

Claude Desktop only supports stdio. The configurator picks stdio for it even when HTTP is selected. Manual config on macOS and Linux:

{
  "mcpServers": {
    "unityMCP": {
      "command": "uvx",
      "args": ["--from", "mcpforunityserver", "mcp-for-unity", "--transport", "stdio"]
    }
  }
}

On Windows, set command to the full path of uvx.exe (for example C:/Users/YOUR_USERNAME/AppData/Local/Microsoft/WinGet/Links/uvx.exe).

Cursor

Auto-configuration writes the entry. You then turn on the unityMCP server in Cursor Settings → MCP. Manual config:

{
  "mcpServers": {
    "unityMCP": {
      "url": "http://localhost:8080/mcp"
    }
  }
}

VS Code

VS Code uses servers instead of mcpServers:

{
  "servers": {
    "unityMCP": {
      "type": "http",
      "url": "http://localhost:8080/mcp"
    }
  }
}

Codex and Windsurf

Both appear in the project's client matrix as HTTP clients. They connect automatically after you run the configurator.

Key features of Unity MCP Server

• Control the Unity Editor in natural language: scenes, GameObjects, components, prefabs, materials and assets
• C# script creation and editing, with optional Roslyn script validation
• Run tests, profile and trigger player builds from a chat
• Tool groups (core, animation, ui, vfx, testing, probuilder, profiling, docs, asset_gen and more). Only core is on by default, which keeps prompts small.
• One-click configurator for Claude Desktop, Claude Code, Cursor, VS Code, Windsurf, Cline, Codex, Gemini CLI and others
• Routing across several Unity Editor instances, plus a remote-hosted server option with auth
• Supports Unity 2021.3 LTS through 6.x; free and MIT-licensed

Unity MCP Server tools

• Scene and objects (core): manage_scene, manage_gameobject, find_gameobjects, manage_components, manage_prefabs, manage_camera, manage_physics and manage_material create and edit what is in your scenes.
• Scripts (core): create_script, apply_text_edits, script_apply_edits, validate_script, find_in_file and delete_script let the model write and patch C# code safely.
• Editor and project (core): manage_editor, manage_asset, manage_packages, manage_build, execute_menu_item, read_console, refresh_unity and batch_execute, which runs several commands in one call.
• Optional groups: run_tests and get_test_job (testing), manage_shader and manage_vfx (vfx), manage_ui, manage_animation, manage_profiler, manage_probuilder, and the asset_gen tools such as generate_model and generate_image. These need your own provider keys.
• Meta: manage_tools turns groups on and off for each session, for example manage_tools(action="activate", group="vfx"). set_active_instance picks which Editor to target.

Use cases of Unity MCP Server

• Block out a level by describing it: "Create a red, blue, and yellow cube in the current scene."
• Prototype gameplay: "Build a simple player controller with WASD movement and a double-jump."
• Audit code: "List every script in Assets/Scripts and tell me which ones reference Rigidbody."
• Fix errors faster: ask the assistant to read the console, patch the script and refresh Unity.
• Run the test suite and fix failures in one conversation, after you turn on the testing group.
• Switch build platforms or start player builds without leaving your IDE.

Unity MCP Server vs alternatives

• Unity's official MCP server: Unity ships its own MCP server with the AI Assistant package in the Unity AI beta. It needs Unity 6 or later, a project connected to Unity Cloud, and a trial or subscription to Unity's AI tools (Unity blog). MCP for Unity is free, open source and supports older LTS versions.
• Other engines: for Godot see Godot MCP Server, and for 3D asset work see Blender MCP Server. MCP for Unity's blender_bridge tool can talk to a running Blender with the BlenderMCP addon.

Troubleshooting Unity MCP Server

• Package Manager says "Error when executing git command": the Git URL install needs git on your PATH. Install Git, or use OpenUPM or the Asset Store instead.
• Server not starting: check that uv --version works in your terminal, then look at the MCP for Unity log.
• Client not connecting: make sure the HTTP server is running on localhost:8080 and the URL in your client config matches. In Cursor, also enable the server in its MCP settings. Port 8080 can clash with other services (Tailscale is one example), and you can change the port in the MCP for Unity settings.
• "Claude Not Found" on macOS: Unity launched from Finder or Hub may not inherit your shell PATH. Launch Hub from Terminal, or use "Choose Claude Install Location" in the MCP for Unity window.
• System.Collections.Immutable conflicts on Unity 6.3+ with the Unity AI Assistant package: the project docs suggest installing System.Collections.Immutable v9.0.0 as a DLL in Assets/Plugins/.