Doorway, an endless world that AI invents room by room

Doorway is an endless first-person 3D world. Every room behind a door is invented live by Grok 4.6, down to the colors, fog, lights, shapes, and motion.

When you walk into a room, it starts building the rooms behind the other doors, so there is no loading screen. You can also press T and say what room you want.

It remembers the last 8 rooms and how you play, like how long you stay and which doors you pick, and it shows what it learned on screen.

I built it for a Cursor and Grok hackathon with my teammate Ashley. I did the engine, the prompt, and the prefetching, and Ashley did the visuals, lighting, door glow, and title card. It runs in the browser on three.js with a small Node server and no other dependencies.