OpenAI announced GPT-6 Sol and GPT-6 Luna on September 22, positioning them as more affordable additions to the GPT-6 family alongside GPT-6 Astra. The company says the models bring advances in professional work, factuality, coding, computer use, and alignment to faster, lower-cost tiers.
A lower-cost GPT-6 tier
OpenAI says improved caching and inference let it reduce API prices for Sol and Luna by 50% against GPT-5.6 promotional pricing. The announcement lists Sol at $2 per million input tokens and $10 per million output tokens, and Luna at $0.10 per million input tokens and $0.50 per million output tokens.
Rollout across Work, Codex and the Luna app
The announcement identifies the API model IDs as gpt-6-sol and gpt-6-luna. OpenAI says both models are rolling out gradually to ChatGPT Work and Codex plans, while Luna is also available in the desktop app for Free and Go users; the models are not available in ChatGPT at launch.
The pricing, capability comparisons, and availability details are reported claims from OpenAI's official announcement. This article does not treat the company's internal benchmark results as independently reproduced, and availability may change during the staged rollout.