Two refreshed versions of the latest intelligence now provide coding and automation tools to professional subscribers through updated software and developer tools. OpenAI released GPT-6 Sol and GPT-6 Luna on Sept 22 for Plus, Pro, Business, Enterprise, and Edu users via ChatGPT Work and Codex, while making Luna available to free users in the desktop app. The company reduced API costs by 50% compared to GPT-5.6, pricing Sol at $2 per 1M input and $10 per 1M output tokens, and Luna at $0.10 input and $0.50 output. A new prompt caching system further reduces expenses by offering up to 90% discounts on cached input-token reads.

The models prioritize agentic workflows and computer use, with OpenAI reporting that Sol can outperform Claude Opus 5 on the AutomationBench metric at just 9% of the per-task cost. This launch comes amid an intensified pricing war, as Anthropic's newly unveiled Opus 5.5 claims to beat GPT-5.6 Sol on coding benchmarks at roughly one-third the operational cost. Both firms introduced these more affordable options shortly after their respective leaders urged the industry to slow the pace of frontier model development to manage risks.