Unity-MCP-Server

Unity MCP Server

Model Context Protocol implementation for Unity Editor and for games made with Unity.

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Required to install Unity MCP Plugin into Unity Engine to connect it with MCP Server.

Topology

• Client is the MCP client, such as VS Code, Cursor, Claude Desktop, Claude Code etc.
• Server is the MCP server, this is Unity-MCP server implementation which works closely in pair with Unity MCP Plugin
• Plugin is the Unity-MCP Plugin, this is deeply connected with Unity Editor and runtime game build SDK, that exposes API for the Server and lets the AI magic to happen. It utilizes advanced reflection by using ReflectorNet

Connection chain

Client <-> Server <-> Plugin (Unity Editor / Game Build)

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Variables

Doesn't matter what launch option you choose, all of them support custom configuration using both Environment Variables and Command Line Arguments. It would work with default values, if you just need to launch it, don't waste your time for the variables. Just make sure Unity Plugin also has default values, especially the --port, they should be equal.

Environment Variable	Command Line Args	Description
MCP_PLUGIN_PORT	--port	Client -> Server <- Plugin connection port (default: 8080)
MCP_PLUGIN_CLIENT_TIMEOUT	--plugin-timeout	Plugin -> Server connection timeout (ms) (default: 10000)
MCP_PLUGIN_CLIENT_TRANSPORT	--client-transport	Client -> Server transport type: stdio or streamableHttp (default: streamableHttp)

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Launch

Unity-MCP server is developed with idea of flexibility in mind, that is why it has many launch options.

Option: Using Docker (recommended)

Default launch

The default the transport method is streamableHttp. The port 8080 should be forwarded. It will be used for http transport and for plugin <-> server communication

docker run -p 8080:8080 ivanmurzakdev/unity-mcp-server

MCP client config:

{
  "mcpServers": {
    "ai-game-developer": {
      "url": "http://localhost:8080"
    }
  }
}

Use STDIO

The 8080 port is not needed for STDIO, because it uses the STDIO to communicate with Client. It is a good setup for using in a client with automatic installation and launching. Because this docker command loads the image from docker hub and launches immediately.

docker run -t -e MCP_PLUGIN_CLIENT_TRANSPORT=stdio -p 8080:8080 ivanmurzakdev/unity-mcp-server

MCP client config:

{
  "mcpServers": {
    "ai-game-developer": {
      "command": "docker",
      "args": [
        "run",
        "-t",
        "-e",
        "MCP_PLUGIN_CLIENT_TRANSPORT=stdio",
        "-p",
        "8080:8080",
        "ivanmurzakdev/unity-mcp-server"
      ]
    }
  }
}

Custom port

docker run -e MCP_PLUGIN_PORT=123 -p 123:123 ivanmurzakdev/unity-mcp-server

MCP client config:

{
  "mcpServers": {
    "ai-game-developer": {
      "url": "http://localhost:123",
      "type": "streamableHttp"
    }
  }
}

Port forwarding is need for the launch with docker -p 123:123.

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Option: Using binary file

Download binary from the GitHub releases page. Unpack the zip archive and use command line to simply launch binary of the server for your target operation system and CPU architecture.

Default launch (STDIO)

./unity-mcp-server --client-transport stdio

MCP client config:

{
  "mcpServers": {
    "ai-game-developer": {
      "command": "C:/unity-project/Library/mcp-server/win-x64/unity-mcp-server.exe",
      "args": [
        "--client-transport=stdio"
      ]
    }
  }
}

Launch STDIO (Local)

Launch server with STDIO transport type for local usage on the same machine with Unity Editor.

./unity-mcp-server --port 8080 --plugin-timeout 10000 --client-transport stdio

MCP client config:

{
  "mcpServers": {
    "ai-game-developer": {
      "command": "C:/unity-project/Library/mcp-server/win-x64/unity-mcp-server.exe",
      "args": [
        "--port=8080",
        "--plugin-timeout=10000",
        "--client-transport=stdio"
      ]
    }
  }
}

Launch HTTP(S) (Local OR Remote)

Launch server with HTTP transport type for local OR remote usage using HTTP(S) url.

./unity-mcp-server --port 8080 --plugin-timeout 10000 --client-transport streamableHttp

MCP client config:

{
  "mcpServers": {
    "ai-game-developer": {
      "command": "C:/unity-project/Library/mcp-server/win-x64/unity-mcp-server.exe",
      "args": [
        "--port=8080",
        "--plugin-timeout=10000",
        "--client-transport=streamableHttp"
      ]
    }
  }
}

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