gbs-toolkit

A Claude Code toolkit for GB Studio 4.x game development.

The model can read & patch GB Studio resources, build the ROM, drive an emulator, and verify changes via screenshot — all through structured MCP tools instead of fragile .gbsproj text edits.

Packages

Repo	Purpose
claude-gbs-marketplace	Claude Code plugin marketplace
claude-gbs-plugin	The plugin itself — skills + .mcp.json
mcp-server	MCP server — published as @gbs-toolkit/mcp-server on npm

Reference demos

Repo	Genre	Status
claude-gbs-mbti-demo	MBTI personality quiz	working ROM
claude-gbs-rpg-demo	Top-down RPG	skeleton
claude-gbs-platformer-demo	Side-scrolling platformer	skeleton
claude-gbs-maga-demo	Satirical text-adventure	skeleton

Quick start

In any Claude Code session:

/plugin marketplace add https://github.com/gbs-toolkit/claude-gbs-marketplace
/plugin install gbs@gbs-toolkit

Then clone the demo to try it end-to-end:

git clone https://github.com/gbs-toolkit/claude-gbs-mbti-demo
cd claude-gbs-mbti-demo
cp .mcp.json.example .mcp.json   # edit, fill in OPENAI_API_KEY
claude

What’s inside the plugin

• MCP tools for structured edits — patch_script, set_variable, create_scene/actor/trigger/variable/custom_event, delete_*, set_start_scene, build_rom, run_emulator, screenshot, generate_sprite, convert_image_to_sprite.
• safety-rules skill — auto-loads on any GB Studio conversation; encodes hardware caps, the 4.x per-resource on-disk layout, and the mandatory build → emulator → screenshot feedback loop.
• Topic skills — gbvm-scripting, dialogue-and-ui, sprite-generation, actor-patterns, scene-design, debugging-rom.

License

MIT.