GPT-5.6 comes in three model tiers. → Sol handles long-horizon coding and agentic work that demands planning, tool use, and follow-through. → Terra balances pe

GPT-5.6 comes in three model tiers. → Sol handles long-horizon coding and agentic work that demands planning, tool use, and follow-through. → Terra balances performance and cost for everyday work. → Luna brings speed to well-defined, high-volume work. Across knowledge-work evaluations, GPT-5.6 Ter…