OpenAI previews GPT-5.6 Sol, Terra, and Luna
A new model family — Sol (most capable), Terra (a cheaper balanced option), and Luna (fastest and lowest-cost) — out first as a limited preview to vetted partners through the API and Codex.
GPT-5.6 arrives as three models: Sol, the flagship; Terra, a lower-cost balanced option that OpenAI says matches GPT-5.5 at roughly half the price; and Luna, the fastest and cheapest. The family targets software engineering, computer use, knowledge work, scientific research, and cybersecurity — where Sol is OpenAI's most capable model yet, including long-horizon vulnerability research. That capability is why the rollout is unusual: at the U.S. government's request it begins as a limited preview for trusted partners via the API and Codex, with general availability said to follow in the coming weeks.
Read the source