OpenAI has announced a limited preview of its new GPT-5.6 model lineup, introducing three tier-based systems named Sol, Terra, and Luna. Sol has been described by the AI giant as its most capable model for cybersecurity.
The initial launch follows a consultation process with the United States government, resulting in a restricted early rollout to a select group of trusted partners.
OpenAI indicated that this phased release is a temporary measure while the organization collaborates with the federal administration to develop a framework aligned with the recent Executive Order, which enables the government to assess the national security risks posed by advanced AI systems.
The GPT update marks a shift in OpenAI’s branding strategy, where version numbers designate the model generation, while the names represent permanent capability tiers. GPT-5.6 Sol is the premier flagship model, designed for high-intensity reasoning tasks. GPT-5.6 Terra targets everyday workloads, with OpenAI reporting performance competitive with GPT-5.5 at half the operating cost. GPT-5.6 Luna is positioned as a fast alternative representing the lowest pricing point in the lineup.
In cybersecurity tests on ExploitBench, Sol matched competing systems like Mythos Preview while using roughly a third of the output tokens.
