Introducing GPT-5.6 series of models

TL;DR: OpenAI is previewing GPT-5.6 in three variants (Sol, Terra, and Luna), with Sol delivering state-of-the-art reasoning, coding, science, and cybersecurity performance, slightly outperforming Claude Mythos 5 while using roughly 80% fewer output tokens on ExploitBench. OpenAI is initially rolling it out to a limited group while completing a temporary U.S. government AI safety review before broader availability.