GPT-5.6 Luna
OpenAI · 2026-07-09
GPT-5.6 Luna is OpenAI's cost-optimized model in the GPT-5.6 family, designed for high-volume workloads and roughly corresponding to the nano tier in earlier GPT-5 families. It is a closed reasoning model with text and image input, a 1.05-million-token context window, and broad built-in tool support.