GPT-5.6 (Sol, Terra, Luna)

GPT-5.6 is OpenAI's frontier model family comprising three tiers — Sol (flagship), Terra (balanced), and Luna (fastest and most cost-efficient) — designed for general-purpose reasoning, coding, agentic workflows, and knowledge work. The family is available across ChatGPT, Codex, and the OpenAI API. Source: supabase.