What Happened
On 2026-09-22, OpenAI expanded GPT-6 with Sol and Luna, making them available in its API, ChatGPT Work, and Codex.
Why It Matters
The new variants spread methods behind Astra into less expensive models, making the agentic generation practical across more budgets and workloads. It also made product boundaries explicit: access through an API or an agent workspace was distinct from availability in the conversational Chat surface. That separation helps explain the rollout history of the GPT-6 family.
Technical Details
API names were gpt-6-sol and gpt-6-luna. Standard input/output prices per million tokens were $2/$10 for Sol and $0.10/$0.50 for Luna. They were not initially available in ordinary Chat. The announcement also described improvements to context caching.