GPT-5.6 Sol

GPT-5.6 Sol is OpenAI’s flagship model in the GPT-5.6 family, built for frontier reasoning, complex coding, multi-step agentic work, and cybersecurity research. OpenAI first shipped it as a locked-down preview to a small group of US-government-vetted organizations in late June 2026, then opened it to the public on July 9, 2026 after regulatory review cleared wider access. It carries the family’s 1.05 million token context window and 128,000 token output limit, priced at $5 per million input tokens and $30 per million output tokens, the highest tier of the three. OpenAI says Sol launched with its most extensive safety stack yet, adding tighter controls around sensitive cyber-related requests and repeated misuse attempts given its stronger offensive and defensive security capabilities. Rather than reporting the older MMLU-style academic scores, OpenAI emphasized agentic and practical benchmarks for this release, a shift several independent reviewers noted as a departure from prior GPT-5.x announcements.