OpenAI debuts GPT-5.6 series with advanced agentic reasoning and tiered pricing (opens in new tab)

OpenAI has launched a limited preview of its GPT-5.6 model family, introducing three distinct tiers named Sol, Terra, and Luna. The flagship Sol model features a "max reasoning" mode for deep problem-solving and an "ultra" mode that utilizes subagents to manage complex, multi-step projects. While Terra offers a balance of performance and cost, Luna is positioned as the fastest and most affordable option for high-volume workflows. <a href="