construct-factory

A factory for generating Construct 3 games programmatically, exposed to Claude (or any MCP client) as an MCP server.

Construct 3 has no public remote-editor API. The automation surface this project targets is the project-folder save format: a Construct 3 project saved as a folder of JSON files (project.c3proj + layouts/, eventSheets/, objectTypes/, …). We read/write those files directly — no browser required. The human only opens the folder in Construct 3 to preview/export/publish.

Layout

packages/
  c3-format/     Read/write/validate the .c3proj project-folder format (the schema layer)
  c3-builder/    High-level authoring API: createGame, addLayout, addObject, addEvent, …
  mcp-server/    Thin MCP server exposing c3-builder operations as tools
  factory-core/  Shared genre templates + scaffolds (the "factory" layer)
games/           One folder per generated game
reference/       Real Construct 3 project folders used to reverse-engineer the schema
verify/          Validation harness (does the output parse / round-trip cleanly?)

Related MCP server: @gbs-toolkit/mcp-server

Templates

Two kinds:

• Builder templates (blank, hello-text) — assembled from scratch via c3-builder against the reverse-engineered schema.js.

• Clone templates — stamped out by a full-fidelity folder clone of a verified real project in reference/, so every byte (images, animations, particles, effects, timelines, event logic) is preserved and guaranteed to open in Construct:

  • kenney-platformer — Kenney's CC0 tile platformer (Player + Platform behavior, Tilemap, coins, enemies).

  • cave-boy — Scirra's Cave Bridge template (animated player, parallax vegetation, particles, area lighting, Tween/Timeline).

generateGame({ rootDir: "games", name: "Cave Boy Adventure", template: "cave-boy" });

The format layer round-trips these real projects losslessly (read → write to a new folder is byte-identical, verified in verify/).

Building from scratch

The c3-builder API also assembles projects without a reference. Sprites emit real PNG files per animation frame (pass images, or get a generated solid placeholder) and link them through imageSpriteId, so built-from-scratch sprites actually render:

const g = Game.create({ rootDir: "games", name: "Scratch Platformer" });
g.addLayout({ name: "Level1", makeFirst: true });
g.addSprite({ name: "Player", width: 24, height: 24, originY: 1,
  animName: "Walk", isLooping: true, behaviors: ["Platform", "solid"],
  images: ["player-walk-000.png", "player-walk-001.png"] });
g.placeInstance({ layout: "Level1", object: "Player", x: 100, y: 200 });
await g.save();

Editing a cloned project

list_level, move_instance, duplicate_instance, list_assets and replace_image customize a cloned reference game by editing its real instance JSON and swapping art — no schema guesswork.

⚠️ Status

The hand-written field shapes in packages/c3-format/src/schema.js are reverse-engineered; sprites, animations, behaviors and instances are verified against the reference/ projects, but exotic features (effects, families, timelines, particles) are only guaranteed via the clone path, which copies ground truth verbatim. When in doubt, clone.

Quick start

npm install
npm run smoke      # generate a tiny game into games/ and round-trip it
npm run verify     # validate a project folder
npm run mcp        # start the MCP server on stdio

Wiring into Claude Code

claude mcp add construct-factory -- node /Users/zubeidhendricks/construct-factory/packages/mcp-server/src/index.js