gmod-mcp

MCP server to allow an AI Agent to interact with a Garry’s Mod dedicated server. The goal is to provide an interface that translates natural language into actions within GMod.

Features

• Support for communication between an AI Agent and GMod server via MCP.
• Includes an addon for GMod gmod-mcp-addon, providing custom console commands to automate actions in the game.
• MCP Server is implemented in Java using Spring AI to connect the AI Agent with GMod.

Project Structure

gmod-mcp
├── gmod-mcp-addon: Lua addon for Garry’s Mod server
│   └── lua
│       └── autorun
│           └── server: addon server-side scripts
├── gmod-mcp-springboot: mcp server
│   └── src
│       └── main
│           ├── java: Java source code
│           │   └── io.github.angelcen14.gmodmcp
│           │       ├── client: client classes for gmod rcon
│           │       ├── config: configuration classes
│           │       ├── service: service classes, mcp tools
│           │       └── model: data models
│           └── resources: application resources
├── build.py: build script
└── .env.example: example environment file

Building

Requirements

• Java 21
• Python 3
• Maven 3
• Node.js 24 and Npx 11

Environment Configuration

Create a .env file following .env.example

1. Run the build script

• Build mcp server

  python build.py mcp

• Build mcp server skipping tests

  python build.py mcp --skipTests

• Build mcp server and run it in mcp inspector

  python build.py mcp --runInspector

• Future upgrades:
  • Move gmod addon to gmod server directory

    python build.py addon

  • Build both mcp server and gmod addon

    python build.py all

  • Add .env variable to customize output jar file location:

    MCP_SERVER_JAR_OUT_DIR=custom/path/

Usage

Add the following configuration to your mcp.json file:

{
    "servers": {
        "test-mcp": {
            "command": "java",
            "args": [
                "-Dspring.ai.mcp.server.stdio=true",
                "-jar",
                "your/absolute/path/gmod-mcp-x.x.x.jar",
                "--gmodrcon.host=your-gmod-server-ip",
                "--gmodrcon.port=your-gmod-server-port(default-27015)",
                "--gmodrcon.password=your-gmod-rcon-password"
            ]
        }
    }
}