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 newest frontier AI model GPT-5.6 family, which comes in three variants: Sol, Terra, and Luna. Sol is for the hardest problems, such as complex coding and security research; Terra is for high-volume business tasks like customer support, internal tools and document analysis; and Luna is for faster, lower-cost everyday work like summarization, drafting and routine automation. Sol and Terra set new high benchmark scores, while Luna performs near GPT-5.5 levels on several tests despite being positioned as the fastest and lowest-cost model in the GPT-5.6