Models · 9 July 2026

GPT-5.6 splits into three tiers: Sol, Terra and Luna

OpenAI released GPT-5.6 in three tiers: Sol as the flagship, Terra as a mid-tier model, and Luna as the low-cost option, priced from $5/$30 down to $1/$6 per million tokens at launch. The release added an ultra mode that runs several agents in parallel and Programmatic Tool Calling for more efficient tool use. For developers, the tiered lineup made it easier to route tasks by cost, and prices were cut twice more in the following weeks.