On October 22, 2026, OpenAI’s developer changelog said the Decisions API, first released in beta on October 6, is now generally available with gpt-6-luna.
What changed since the beta
- More questions: each request supports up to 400 questions, up from 200 in the public beta.
- Caching: shared input can be cached across requests for prompt-cache discounts.
- Images: you can include images in individual question instructions.
- Structured data: pass structured data directly with
input_json.
OpenAI documents the details in its Decisions guide.
Why it matters
The API is aimed at batches of many small judgement questions about the same material, such as classifying or scoring items. Good questions still come first: keep each one short, give the allowed answers and say what to do when the input is unclear. See our prompt workflow guide, the earlier prompt-to-voice update and the ChatGPT page.
Update, November 12, 2026: Google has launched a similar product, the Gemini Decisions API, with up to 1,000 questions per request. Our question templates work for both, with the field names adjusted.
Source: OpenAI API changelog. We summarise in our own words; check the source for the full details.