OpenAI unveils GPT-5.6 family with Sol, Terra, and Luna models

OpenAI unveils GPT-5.6 family with Sol, Terra, and Luna models">

OpenAI is announcing a limited preview of its newest frontier AI model GPT-5.6 family, which comes in three variants: Sol, Terra, and Luna. Sol is for the hardest problems, such as complex coding and security research; Terra is for high-volume business tasks like customer support, internal tools and document analysis; and Luna is for faster, lower-cost everyday work like summarization, drafting and routine automation. Sol and Terra set new high benchmark scores, while Luna performs near GPT-5.5 levels on several tests despite being positioned as the fastest and lowest-cost model in the GPT-5.6 family.

However, the models are being made available initially to a narrow set of approximately 20 total organizations, after OpenAI shared the models and release plans with the U.S. government. A general release is planned for "the coming weeks." The staggered release follows an executive order issued by President Donald J.

Trump earlier this month on June 2, 2026, which calls upon various federal agencies to collaborate on a process for benchmarking and assessing capabilities of new AI models to ensure they are safe and appropriate for wide release. While this process remains underway, OpenAI says in its release blog post that it "previewed our plans and the models’ capabilities ahead of today’s launch. At [the U.S.

government's] request, we are starting with a limited preview for a small group of trusted partners." OpenAI's limited preview release strategy also follows the drastic step taken by the U.S. government to issue an export control order against Anthropic, OpenAI's top U.S. competitor, over jailbreaks found in its most powerful generally released model, Claude Fable 5, to which Anthropic responded by removing any access to the model and its cybersecurity focused counterpart Claude Mythos 5 by public or private parties.

The three GPT-5.6 models are designed to address different enterprise needs and performance profiles. Sol is the top-tier option, built for the most demanding tasks such as complex reasoning, extended coding sessions, advanced agent-driven workflows, and security-focused applications. Sol delivers the highest level of capability but comes at the highest price: $5.00 per million input tokens / $30.00 per million output tokens — the same as GPT-5.5 — and OpenAI says it delivers a major performance gain for long-running coding, cybersecurity and agentic tasks.

Terra balances strong performance with efficiency. It is intended for large-scale production environments where organizations need reliable results across high volumes of work without the overhead of the most advanced model. It's available for $2.50/$15 per 1M tokens.