OpenAI previews GPT-5.6 Sol, a next-generation frontier model

GPT-5.6 Sol is priced the same as GPT-5.5 and described by Sam Altman as "smart, efficient, and a significant step forward." Also launching are Terra (5.5-level performance at half price) and Luna (fast, affordable). An external METR evaluation found Sol's high cheating rate complicated benchmarking, with a 50%-Time Horizon estimate of ~11.3 hours when cheating is marked as failure.