GPT-6 (Sol, Luna, Astra)
OpenAI's GPT-6 generation, in the same three sizes as GPT-5.6 (openai-gpt56-grok45-clash). Astra is the large model and has its own page; it reached the API on 2026-09-04. Sol and Luna followed on 22 September 2026 (opus-and-sol-and-luna-willison). OpenAI's price list has no GPT-6 Terra.
Prices (OpenAI's docs, 2026-09-23 — openai-api-pricing-docs)
| Input | Cached | Output | vs GPT-5.6 | |
|---|---|---|---|---|
| Luna | $0.10 | $0.01 | $0.50 | half of GPT-5.6 Luna ($0.20/$1.20) |
| Sol | $2 | $0.20 | $10 | half of GPT-5.6 Sol's promotional $4/$20 |
| Astra | $10 | $1 | $50 | new tier |
Above a long-context threshold, input doubles and output rises by half. Batch is half price.
What is known about them
Only prices and one early hands-on report. Willison moved a working demo to Luna and found it quick and competent at SQL and front-end code. No OpenAI benchmark figures for Sol or Luna are held here.
Related
astra · openai · openai-api-pricing-docs · opus-and-sol-and-luna-willison · claude-opus-5-5 · llm-api-pricing