GPT-5.6 system card details step-function improvement over GPT-5.5

OpenAI's system card for GPT-5.6 claims a step-function improvement over GPT-5.5, with pricing at $5/$30 for Sol, $2.5/$15 for Terra, and $1/$6 for Luna. The card introduces new thinking settings, including Max and Ultra, the latter capable of spawning sub-agents.