GPT-5.6 family released: Sol, Terra and Luna, with Programmatic Tool Calling

Released the GPT-5.6 model family, including GPT-5.6 Sol for frontier capability, GPT-5.6 Terra for a balance of intelligence and cost, and GPT-5.6 Luna for efficient, high-volume workloads. The gpt-5.6 alias routes requests to gpt-5.6-sol.

GPT-5.6 adds Programmatic Tool Calling, explicit prompt caching controls, persisted reasoning, max reasoning effort, and Pro mode, and Multi-agent orchestration in beta for the Responses API. GPT-5.6 also accepts images at their original dimensions with original or auto image detail.