OpenAI has launched a limited preview of its GPT-5.6 model series, which includes Sol, Terra, and Luna for different levels of performance, speed, and cost. Sol is the company’s strongest model so far, while Terra targets everyday work at a lower price, and Luna offers faster access at OpenAI’s lowest cost.
OpenAI says GPT-5.6 Sol brings major improvements in coding, biology, and cybersecurity tasks, with a new max reasoning effort for deeper thinking and an ultra mode that uses sub-agents for complex work. The company says Sol performs strongly on command-line coding workflows, genomics analysis, and long security tasks that require planning and tool use.
The GPT-5.6 launch will start with trusted partners because the Trump administration requested a limited rollout while it works on a process to review advanced AI models before wider release. OpenAI says it agreed to this short-term step, but it also pushed back against making government access reviews the default path for future model launches.
OpenAI also says GPT-5.6 uses its strongest safety system so far, with stronger protections for cyber requests, biology risks, repeated misuse, jailbreak attempts, and high-risk activity. The company says the model helps users find and fix vulnerabilities better than it carries out full attacks.
GPT-5.6 models are now available through the API and Codex for select partners, with wider access planned for ChatGPT, Codex, and the API soon. Pricing starts at $5 input and $30 output per 1 million tokens for Sol, $2.50 input and $15 output for Terra, and $1 input and $6 output for Luna.
