MCP Unity 🔌 MCP server Open source

What it does

MCP Unity runs a Node.js/WebSocket bridge inside the Unity Editor that implements the Model Context Protocol, letting an AI coding agent inspect and manipulate a live Unity project — creating and editing GameObjects, scenes, materials and prefabs, running tests, and reading console/asset state — instead of only editing C# files blind to the Editor's actual state.

Tools it gives your agent

Editor manipulation: create/select/update/duplicate/delete/reparent GameObjects and transforms, add or update components with serialized fields, create/load/unload/save scenes, create and modify materials and shaders, instantiate prefabs into scenes, execute [MenuItem]-tagged functions, trigger script recompilation, and read the Console. Project tools cover Package Manager installs, the Unity Test Runner (EditMode/PlayMode), and play-mode control (play/pause/stop/step). Resources expose the menu-item catalog, scene hierarchy, per-GameObject component details, paginated console logs, package info and the asset database.

Works with

Explicitly documented for Cursor, Windsurf, Claude Code, Codex CLI, GitHub Copilot, Google Antigravity and OpenCode, each with its own config snippet in the README.

How to install or connect

Install as a Unity package (Window > Package Manager > "+" > Add package from git URL):

https://github.com/CoderGamester/mcp-unity.git

Then start the bridge from Tools > MCP Unity > Server Window > "Start Server" (default WebSocket port 8090). For an MCP client, add to its config:

{
  "mcpServers": {
    "mcp-unity": {
      "command": "node",
      "args": ["ABSOLUTE/PATH/TO/mcp-unity/Server~/build/index.js"]
    }
  }
}

Claude Code, Cursor, Windsurf, Codex CLI and GitHub Copilot each use an equivalent per-client config file shown in the README.

Maintenance and safety

Actively maintained (1.9k stars, 245 forks, 316 commits, MIT license, low open-issue count). Each project gets a per-project 256-bit auth token stored locally, and package installation via the bridge is disabled by default. The default ws:// transport is unencrypted, so the README recommends restricting remote connections to trusted networks or a VPN.

Who should use it

Unity developers who want an AI agent to actually operate the Editor — building scenes, wiring components and running tests — rather than just editing script files with no feedback from the running project.