OpenAI unveils GPT-5.6 Sol, Terra and Luna models — but only accessible to limited preview partners for now, per US Gov

OpenAI is announcing a limited preview of its next-generation GPT-5.6 model series today, introducing three distinct, capability-tiered models—Sol, Terra, and Luna—designed to re-engineer developer and enterprise workflows. Rolled out initially to a select cohort of approximately 20 trusted organizations in coordination with the U.S. government, the new series establishes a permanent shift toward multi-agent architecture, deep-reasoning configurations, and granular token pricing.