OpenAI rolled out GPT-5.6 across ChatGPT, Codex, and the API on July 9, 2026, introducing three capability tiers named Sol (flagship), Terra (balanced, 2x cheaper than Sol), and Luna (fast/low-cost). Sol is priced at $5 input / $30 output per million tokens; Terra at $2.50 / $15; Luna at $1 / $6. The release includes a new 'Ultra' effort level that coordinates four agents in parallel, trading higher token use for faster time-to-completion on complex multi-step tasks.
Sol delivers strong benchmark results: Artificial Analysis reports a Coding Agent Index score of 80, ahead of Claude Fable 5 (72) and outperforming Opus 4.8, while using fewer tokens and costing less. OpenAI claims Terra matches GPT-5.5 performance at half the cost, and Luna outperforms Opus 4.8. Sam Altman called Sol 'obviously the best model we have ever produced.' The company also reports Sol is 54% more token-efficient for coding tasks and achieves state-of-the-art results on Terminal Bench 2.1 and DeepSWE, which measure complex command-line workflows and long-horizon engineering.
The staggered rollout follows a limited preview (June 26) restricted to US government-approved partners, reflecting compliance with Trump's June 2 AI Executive Order mandating federal testing frameworks. OpenAI also launched ChatGPT Work (enterprise productivity suite) and merged Codex into the new ChatGPT desktop app for macOS/Windows, with GPT-5.6 Sol also available on Cerebras hardware at up to 750 tokens/second for high-throughput enterprise inference. General public availability is planned for coming weeks pending government clearance.