OpenAI releases GPT-5.6 Sol, Terra, Luna models publicly after two-week government review

OpenAI will publicly release its GPT-5.6 Sol, Terra and Luna models on Thursday, ending a two-week period where access was limited to a "small group of trusted partners" at U.S. government request.

"Happy building," OpenAI CEO Sam Altman wrote on X late Tuesday announcing the expanded release.

Government review process

OpenAI announced the three GPT-5.6 models in June but initially agreed to release them only to select organizations "whose participation has been shared with the government," according to the company's blog post. At the time, OpenAI stated it would work to make the models more widely available within weeks.

"We don't believe this kind of government access process should become the long-term default," OpenAI said in June. "It keeps the best tools from users, developers, enterprises, cyber defenders, and global partners who need them."

The restricted release followed a June executive order from President Donald Trump that asks AI developers to voluntarily provide cutting-edge models to the government for capability assessments before public launch. The order gave federal agencies 60 days to develop an evaluation framework.

Model capabilities

According to OpenAI, GPT-5.6 Sol is the company's "strongest model yet" with enhanced capabilities across coding, biology and cybersecurity. Specific benchmark scores and technical specifications have not been disclosed.

The company said Tuesday it is expanding preview access to the GPT-5.6 models globally.

Industry context

The public launch follows a similar situation with Anthropic, OpenAI's chief rival. Anthropic was forced to disable access to its Claude Fable 5 and Mythos 5 models to comply with an export control directive. The U.S. Department of Commerce lifted that directive late last month, allowing Anthropic to restore access.

OpenAI said in June it is working with the government to establish a framework for model assessments and develop a "repeatable process for future model releases."

Pricing information for the GPT-5.6 models has not been disclosed.

What this means

The two-week government review represents a new phase in AI regulation where leading model developers coordinate releases with federal agencies. While OpenAI criticized the process as potentially limiting access to critical tools, the company participated in establishing what may become standard practice for frontier model deployments. The pattern established by both OpenAI and Anthropic suggests voluntary pre-release government reviews are becoming the de facto norm for advanced AI systems, despite neither company publicly supporting this as a long-term approach.