gm-forge-mcp

gm-forge-mcp is an MCP server that lets an AI assistant create and edit GameMaker projects: scripts, objects, rooms, sprites, sounds, and the rest of the .yyp catalog. In practice that means you can ask Claude to scaffold a new project, import a folder of sprite frames, or rename an object everywhere it's referenced, and the project still opens in the IDE afterwards.

Early stage (0.1.0) - back up your project before letting anything write to it.

GameMaker's file format punishes sloppy edits quietly. A room missing its creationCodeFile field, or a sound whose declared sample rate doesn't match the real .wav, can look fine right up until the IDE fails to open the project or crashes. Every writer here is modeled on files GameMaker itself produced, and two tools use GameMaker's own tooling directly: lint_project runs the official headless validator (ProjectTool) and compile_project runs the real compiler (Igor), which catches actual GML errors.

Requirements

• Node.js 20+

• GameMaker (Windows) for lint_project's ProjectTool check and for compile_project. Both skip with a clear message when GameMaker isn't installed; everything else works cross-platform.

Related MCP server: GM-Maker MCP Server

Install

git clone https://github.com/nicklesimba/gm-forge-mcp.git
cd gm-forge-mcp
npm install
npm run build

Configure

Add to your MCP client config (e.g. Claude Desktop's claude_desktop_config.json):

{
  "mcpServers": {
    "gm-forge": {
      "command": "node",
      "args": ["/absolute/path/to/gm-forge-mcp/dist/index.js"]
    }
  }
}

Tools

Projects -- create_project, list_resources, find_references, delete_resource, rename_resource, lint_project, compile_project

Groups -- add_texture_group, add_audio_group

Scripts -- add_script, edit_script, get_script_info

Objects -- add_object, add_object_event, get_object_info

Rooms -- add_room, edit_room, add_room_instance, reorder_room, move_room_relative, get_room_info, find_tile_region

Sprites -- add_sprite_from_images, edit_sprite, get_sprite_info

Tilesets -- add_tileset, edit_tileset, get_tileset_info

Sounds -- add_sound, edit_sound, get_sound_info

Shaders -- add_shader, edit_shader, get_shader_info

Fonts -- add_font, edit_font, get_font_info

Notes -- add_note, get_note_info

Extensions -- add_extension, get_extension_info

Particle systems -- add_particle_system, get_particle_system_info

Animation curves -- add_anim_curve, get_anim_curve_info

delete_resource and rename_resource search the whole project for references before touching anything.

Testing

npm test

The suite checks every writer's output against reference schemas captured from real GameMaker files, simulates files GameMaker has resaved (trailing commas and all), and runs live ProjectTool/Igor checks when those are installed. CI runs on a Windows runner without GameMaker, so the live checks skip there and the summary reports the skip count. Every resource type has also been loaded in the actual IDE, including a project created from scratch by create_project.

See also

GameMaker is required to use any of this. Thanks to YoYo Games for making game-making more accessible for two decades and counting!

@petah/gamemaker-mcp covers GML function/API reference lookup, which this project doesn't.

License

MIT - see LICENSE.