GPT-5.6: The System Card

OpenAI's system card for GPT-5.6 reveals a family of three models: Sol ($5/$30), Terra ($2.5/$15), and Luna ($1/$6). New thinking modes include 'Max' and 'Ultra', which spawns sub-agents. GPT-5.6-Sol is a 'step function better' than GPT-5.5 and will be available on Cerebras at 750 TPS.