OpenAI previews GPT-5.6 in three flavors: Sol, Terra, and Luna
OpenAI previewed GPT-5.6 as a three-model family: Sol, the flagship; Terra, a balanced everyday model; and Luna, a fast and affordable one. OpenAI calls Sol its strongest model yet, citing improved agentic ability in coding, biology, and cybersecurity, and adds a new max reasoning effort that lets it think longer plus an ultra mode that spins up subagents for complex work. Access is unusual: the models go first to a narrow set of about 20 organizations as part of a staged release, after OpenAI shared them and its rollout plans with the US government, with broader availability promised in the coming weeks.
Why it matters: Beyond raw capability, GPT-5.6 signals two shifts: model families now split into capability-and-cost tiers rather than one size, and frontier releases come with a government-coordinated, staged-access gate. Both change how builders will get — and budget for — the newest models.