What was GPT-6-SOL?

GPT-6-SOL was released on September 22, 2026, with GPT-6.1-SOL following a week later on September 29. The original GPT-6-SOL was available for only seven days and was considered worse than its predecessor, GPT-5.6-SOL. This rapid release and perceived downgrade raised questions about its classification as a Terra-class model and the reasoning behind its deployment.