GPT-5.6 Sol Builds a Voxel Manhattan in a Weeklong Autonomous Run

OpenAI's latest model, "GPT-5.6 Sol," generated a detailed voxel-built 3D model of Manhattan after running fully autonomously for nearly a week, in a demo now made public. The demonstration came from Matt Shumer, former CEO of HyperWrite, who said the model planned, generated and iterated with almost no human intervention from a single task instruction, producing a three-dimensional cityscape captured in a roughly 38-second video. The prompt, repository, logs and execution cost remain undisclosed, but Shumer said he combined the maximum-reasoning "xhigh" setting with instructions to spawn large numbers of subagents in what he called "Ultra mode."