Watch GPT-5.6 build a playable, celestial-themed card game in Codex from a short, open-ended prompt.
In this demo, GPT-5.6 designs the core mechanics, generates custom artwork, adds levels and a soundtrack, tests the gameplay, and keeps improving the build. Along the way, see how programmatic tool calling, Max Reasoning, and subagents help it take on longer-running work – using a sandbox to process tool results, split work in parallel, and bring everything back into one polished game.
Check out the game here:
Chapters
00:00 Introducing GPT-5.6
00:17 Building a game in Codex
00:52 Programmatic tool calling
01:07 Reasoning and subagents
01:35 GPT-5.6 in the API
コメント