GPT-5.6 (Sol, Terra, Luna)

OpenAI's new model family in limited preview: Sol for the hardest work, Terra for everyday tasks, and Luna for fast, low-cost work.

Three models at different price and capability points: Sol is the flagship with the strongest coding, science, and cybersecurity performance, Terra matches the older GPT-5.5 at about half the cost, and Luna is the cheapest option for high-volume work
API pricing per million tokens: Sol is 5 dollars in and 30 out, Terra is 2.50 in and 15 out, Luna is 1 in and 6 out
Adds a new max reasoning setting and an ultra mode that spins up sub-agents for complex tasks
Available to roughly 20 organizations at launch after OpenAI shared the models with the U.S. government, with general availability planned in the coming weeks