Sol

OpenAI has released its latest advanced model, Sol, for public access after government review, but researchers and industry figures say the approval process remains opaque. The model is considered comparable to Anthropic's Fable, which was briefly banned from public access, yet details of how either model received clearance are unclear.

OpenAI released GPT-5.6, a three-model suite consisting of Sol (flagship), Terra (medium-tier), and Luna (fast/affordable). Sol is priced at $5 input/$30 output per million tokens—nearly half the cost of Anthropic's Claude Fable 5. The release follows Trump administration involvement in approval process.