OpenAI launches GPT-5.6 with Sol, Terra, and Luna models for wider public use

OpenAI is rolling out its new GPT-5.6 models to the general public, calling the series “its best coding model yet” and positioning it as a direct competitor to Anthropic’s recently released Fable. The lineup includes three models designed for different performance and cost needs. GPT-5.6 Sol is the flagship option for advanced reasoning, coding, scientific research, cybersecurity, and long-running agentic tasks. Terra offers performance competitive with GPT-5.5 at about half the cost, while Luna is built for faster and more affordable workloads. The public release follows a limited preview restricted to government-approved organizations and trusted partners, with the wider rollout arriving after OpenAI received approval from the U.S. government. GPT-5.6 also introduces max reasoning effort for Sol, which allocates more computation to difficult tasks, and an ultra mode that uses multiple subagents for complex assignments. Sol achieved leading results across several intelligence, coding,...