OpenAI launched GPT-6 Sol and GPT-6 Luna on September 22 as lower-cost additions to its GPT-6 model line.
According to The New Stack, Sol is priced at $2 per million input tokens and $10 per million output tokens. Luna is listed at $0.10 for input and $0.50 for output per million tokens. Reported pricing is at least 50% below the corresponding promotional GPT-5.6 rates.
For automation teams, that creates a clearer cost split: Luna fits high-volume, repetitive agent steps, while Sol is the likelier choice when stronger reasoning matters more. But token pricing alone will not show total operating cost if retries, tool use, or failure handling add overhead.
OpenAI also reported stronger workflow performance for the new models, though those results still come from vendor testing rather than broad third-party validation.
Availability beyond the API rolled out the same day. ChatGPT Work and Codex access opened Tuesday for all paid tiers, matching the API launch. OpenAI's linked Fast mode page still appears to describe older GPT-5.6 service tiers rather than a dedicated Sol and Luna launch page, so the clearest reference remains the main announcement.