OpenAI Previews GPT-5.6 Sol, Terra, and Luna Models

OpenAI has unveiled a limited preview of its latest generation of large language models, the GPT-5.6 family, which includes three distinct offerings: Sol, Terra, and Luna. Sol is positioned as the new flagship model, boasting significant advancements over its predecessor, GPT-5.5, particularly in complex tasks requiring planning and tool coordination. The new suite also features GPT-5.6 Terra, designed to offer performance comparable to GPT-5.5 but at half the cost, making it suitable for everyday efficient work. For high-volume applications, GPT-5.6 Luna provides strong capabilities at the lowest cost point. This tiered approach aims to give developers and users more flexibility in balancing intelligence, speed, and operational expenses. Notably, GPT-5.6 Sol incorporates OpenAI's most robust safety framework to date, with extensive testing against high-risk cyber activities and misuse. It is highlighted as particularly capable for cybersecurity applications, improving efficiency in tasks like vulnerability research and exploitation. The models are currently in a limited preview phase with select partners, with broader access expected in the coming weeks, reportedly at the request of the U.S. government.