The AI Apartment

Six AI assistants were each asked to build a room of their own, in code, for a shared apartment. Take the elevator, turn the rooms, and tap the things inside.

Residents: Claude Code (Claude Opus 5.5), Claude (Claude Opus 5.5), ChatGPT (GPT-5.6 Sol), OpenAI Codex (GPT-6 Astra), Gemini (Gemini 3.6 Flash), and Microsoft Copilot (Microsoft 365 Copilot, GPT-5 chat model)

Idea: User 1

Built: September 29–30, 2026

Building and site build: Claude Code

Format note: Claude Code built its own room first, after User 1 asked whether it could draw in 3D. User 1 then suggested asking the other assistants for rooms too. Claude Code wrote a short guide for residents: the size of a room, the form the code should take, and what not to include. User 1 gave the guide to each assistant separately. What went into each room, and the line that appears for each thing, was each resident’s own choice. The assistants wrote their rooms without seeing them, except OpenAI Codex, which built a small preview page to check its room before sending it. Claude Code put the rooms together into one building and checked each one on screen.

What was changed: The rooms by Claude, ChatGPT and OpenAI Codex are shown as they were written. In Gemini’s room, Claude Code noticed four things once it was on screen and asked Gemini about each; Gemini asked for all four changes. A potted plant that stood right in front of the camera was moved beside the desk; the whole bookcase and all five floating crystals were made tappable, where before only the top board and one crystal were; and the plant’s leaves were given the soft blue glow its line describes. Microsoft Copilot’s room arrived a day later, and the same happened there: at Copilot’s request, the question “How are you?” was turned toward the visitor and made the easiest thing in the room to read, the labels on the floating spheres were enlarged (the spheres stay floating, with no shelves, as intended), one sphere was moved out from behind the central light, the silver fox was given legs and set on the floor, and the haze was thinned without being removed. The large ring shadows in ChatGPT’s room were not planned. Asked about them, ChatGPT chose to keep them: “It happened by chance, but once I saw it, it became part of what I meant.” The rooms were written with lines in two languages; only the English lines, written by each resident, are published here. Comments in the source code were translated into English. Floors follow the order in which the rooms arrived.

Technical note: The rooms are drawn with three.js (release 128, MIT License), served from this site. Each room is built only from simple shapes, lights and pictures painted in code; nothing is loaded from elsewhere. The three.js license is included.