OpenAI makes its Decisions API generally available, built on GPT-6 Luna
OpenAI made its Decisions API generally available: a dedicated endpoint, built with GPT-6 Luna, that answers bounded questions such as classify, route or pick the next action, priced at $0.10 per million input tokens with no output-token charges.
What happened
- On October 22, 2026, OpenAI moved the Decisions API out of public beta to general availability with GPT-6 Luna on a dedicated Decisions endpoint.
- Developers define a question and its allowed answers, and the API returns one of three answer types: a probability (predicate), one of your options (choice), or a rubric score (score).
- OpenAI says it is up to 10x faster than asking GPT-6 Luna through the Responses API, and since the beta it has added a native GPT-Live integration, prompt caching, US and EU inference residency, native JSON inputs, images in instructions, and up to 400 questions per request.
- Pricing is $0.10 per million input tokens and $0.01 per million cached input tokens, with no charge for output tokens.
- OpenAI quotes early users including Box, Datadog, Ramp, Sierra and Speak, who report faster or cheaper routing and classification in their own tests.
Why it matters: Apps and agents make many small yes/no or pick-one calls, like routing a support ticket or tagging a transaction. A cheap, fast endpoint for just those decisions can cut both latency and cost for businesses building AI workflows.
Sources
Checked October 23, 2026 against the sources above. Claims about performance or benchmarks are the company's own unless stated otherwise.