OpenAI launches GPT-6 Sol and Luna models

OpenAI released GPT-6 Sol and Luna on September 22, 2026. Sol is priced at $2 input / $10 output; Luna at $0.10 / $0.50, meaning cost for text sent versus generated. Both are in ChatGPT Work and Codex for Plus, Pro, Business and Enterprise, with Free and Go limited to Luna on desktop. OpenAI says both use Astra training methods.