Gearsystem MCP Server

MCP server for Gearsystem Sega Master System / Game Gear / SG-1000 emulator

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What is the Gearsystem MCP server?

Connect Gearsystem to Claude, Cursor or any other MCP client and it stops being a tab you switch to. MCP server for Gearsystem Sega Master System / Game Gear / SG-1000 emulator. The gearsystem mcp server is what makes that connection.

What the server does

Gearsystem is a very accurate, cross-platform Sega Master System / Game Gear / SG-1000 emulator written in C++ that runs on Windows, macOS, Linux, BSD and RetroArch, with an embedded MCP server for debugging and tooling.

  • Very accurate Z80, VDP, PSG and FM emulation
  • Supported cartridges: ROM, ROM + RAM, SEGA, Codemasters, Korean, MSX + Nemesis, Janggun, SG-1000, and many Korean multi-carts
  • Automatic region detection: NTSC-JAP, NTSC-USA, PAL-EUR
  • Support for YM2413 (OPLL) FM sound chip
  • Light Phaser and Paddle Control support
  • Internal database for ROM detection

Available tools

The toolset is worth reading before you wire it up, because it tells you what the integration is really for:

  • BIOS — Gearsystem can run with or without a BIOS. You can optionally load a BIOS and enable it. It's possible to run the title included in the BIOS by
  • Overscan — For a precise representation of the original image, select Overscan Top+Bottom and Aspect Ratio Standard (4:3 DAR) in the Video menu
  • Windows — The Windows tool exposed by this server
  • macOS — The macOS tool exposed by this server
  • Linux — If you are using Ubuntu 25.04 or later, you can install SDL3 directly. Use the following commands to build:
  • Libretro — The Libretro tool exposed by this server

Installation

Installation goes through your MCP client rather than a global install: point it at skills on npm and it is fetched when the client starts. The copy-paste blocks for Claude Desktop, Claude Code and Cursor are further down this page.

Where it fits

This sits in the database access group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. Gearsystem's toolset — BIOS, Overscan, Windows and 3 more — is a fair guide to whether it matches your workflow. It is maintained by drhelius; worth a glance at recent repository activity before you build anything load-bearing on it.

This entry was verified against Gearsystem's own documentation before publication; SyncDev keeps the directory reviewed rather than auto-generated.

Worth knowing first

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.

Available tools

ToolWhat it does
BIOSGearsystem can run with or without a BIOS. You can optionally load a BIOS and enable it. It's possible to run the title included in the BIOS by setting **Media Slot** to None in the **Emulator** menu. This emulates a mac
OverscanFor a precise representation of the original image, select **Overscan** Top+Bottom and **Aspect Ratio** Standard (4:3 DAR) in the **Video** menu. Game Gear will ignore any overscan settings.
WindowsThe Windows tool exposed by this server.
macOSThe macOS tool exposed by this server.
LinuxIf you are using Ubuntu 25.04 or later, you can install SDL3 directly. Use the following commands to build:
LibretroThe Libretro tool exposed by this server.

How to install the Gearsystem MCP server

{
  "mcpServers": {
    "gearsystem": {
      "command": "npx",
      "args": ["-y", "skills"]
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Example prompts to try

  • Use Gearsystem to BIOS.
  • Use Gearsystem to Overscan.
  • Use Gearsystem to Windows.

Frequently asked questions

It connects Gearsystem to MCP-compatible AI assistants such as Claude and Cursor, exposing 6 tools (BIOS, Overscan, Windows, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Gearsystem directly.