OpenAI launches limited preview of GPT-5.6 Sol, Terra and Luna models

OpenAI announced a limited preview of the GPT-5.6 family: the high-performance GPT-5.6 Sol, the GPT-5.6 Terra designed for everyday efficiency, and the cost-effective, fast GPT-5.6 Luna. The move aims to expand the model lineup and satisfy different usage needs, with preview access.