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, engineering, browsing, and cybersecurity benchmarks, often completing tasks faster and at a lower estimated cost than competing models.

The announcement also came with the launch of ChatGPT Work, a new agent that combines ChatGPT and Codex to complete complex professional tasks across connected apps. API pricing starts at $5 per million input tokens and $30 per million output tokens for Sol, $2.50 and $15 for Terra, and $1 and $6 for Luna. The models are rolling out across ChatGPT, Codex, and the OpenAI API over the next 24 hours.