OpenAI released the GPT-5.6 family to general availability: Sol, its new flagship; Terra, a balanced model for everyday work; and Luna, its most cost-efficient model, adopting a new naming scheme that gives models proper names. Prior to the public release, the rollout had reportedly been limited for roughly two weeks to a small group of trusted partners at the request of the U.S. government, drawing attention as a case of government involvement in the release of a frontier model.