Gearboy

About

Gearboy is an accurate, cross-platform emulator for the Game Boy, Game Boy Color, and Super Game Boy, written in C++. It runs on Windows, macOS, Linux, BSD, and RetroArch, and includes an embedded MCP server for AI-assisted debugging and development. The emulator supports a wide range of cartridge types, Game Boy Color and Super Game Boy modes, local two-instance link cable play on desktop platforms, save states with preview and rewind, run-ahead to reduce input latency, battery-backed saves, Game Genie and GameShark cheats, and a VGM recorder.

For developers and debuggers, Gearboy offers a full debugger with a just-in-time disassembler, CPU and memory access breakpoints, code navigation, debug symbols, a memory editor, a trace logger, an IO inspector, and a VRAM viewer covering tiles, sprites, backgrounds, and palettes. The embedded MCP server exposes tools for execution control, memory inspection, hardware status, and rewind, for use with AI assistants such as Claude Code and Codex.

Gearboy is open source under the GPL-3.0 license. On macOS it can be installed via Homebrew or downloaded as Apple Silicon or Intel builds, and it supports a programmable shader chain, drag-and-drop ROM loading, and controller support via gamecontrollerdb.txt.