GMod MCP Tool

MCP (Model Context Protocol) server for Garry's Mod — RCON, Lua execution, window control, screenshots, and SFTP file management.

Features

• RCON — connect to GMod server, execute commands and Lua code

• Screenshots — capture GMod window, zoom into specific areas, read console [Windows]

• Window Control — focus, send keystrokes, console commands [Windows]

• SFTP — read, write, list, delete files on remote server

Related MCP server: Computer Control MCP

Quick Start

npx gmod-mcp

MCP Client Configuration

Claude Desktop / Claude Code / Cursor:

{
  "mcpServers": {
    "gmod": {
      "command": "npx",
      "args": ["-y", "gmod-mcp"]
    }
  }
}

With SFTP credentials via environment variables:

{
  "mcpServers": {
    "gmod": {
      "command": "npx",
      "args": ["-y", "gmod-mcp"],
      "env": {
        "SFTP_HOST": "your-server.com",
        "SFTP_PORT": "22",
        "SFTP_USER": "root",
        "SFTP_PASSWORD": "your-password"
      }
    }
  }
}

Tools (15)

RCON (4 tools)

gmod_connect

gmod_execute_rcon

Blocked commands: quit, exit, rcon_password, _restart

gmod_execute_lua

Multi-statement code is automatically split by ; into separate lua_run calls. Local variables are converted to _G.__mcp_ globals for cross-statement persistence.

_G.plys = player.GetAll(); print(#_G.plys .. " players online")

Screenshots (3 tools) [Windows only]

gmod_zoom

Window Control (3 tools) [Windows only]

gmod_send_keys

SendKeys format: {ENTER}, {ESCAPE}, {TAB}, {F1}-{F12}, + (Shift), ^ (Ctrl), % (Alt)

gmod_console_command

Experimental: may not work correctly with non-English keyboard layouts.

SFTP (5 tools)

sftp_connect

Requirements

• Node.js >= 18

• GMod server with RCON enabled (rcon_password in server.cfg)

• Windows for screenshot and window control tools

• SSH access for SFTP tools

Security

• Destructive RCON commands (quit, exit, rcon_password) are blocked

• Dangerous Lua functions (file.Delete, RunConsoleCommand, CompileString) trigger warnings

• RCON password is cleared from memory after authentication

• SFTP credentials can be passed via environment variables (no hardcoding)

Troubleshooting

Connection failed — check server is running, RCON password is correct, port is not firewalled

Lua code fails — multi-line code must use ; separators. local variables don't persist between lua_run calls (auto-converted to _G.__mcp_*)

Screenshot returns error — GMod must be running and visible (not minimized). Process name must be hl2.exe or gmod.exe

Console command types wrong characters — switch to English keyboard layout before using gmod_console_command

License

MIT