# Decisions API Explained

> An independent explainer of OpenAI's Decisions API (public beta since 2026-10-06): a POST /v1/decisions endpoint on gpt-6-luna that returns typed decisions instead of prose. Three question types: predicate (probability 0-1), choice (one of your options, with per-option probabilities and confidence), score (probability-weighted average of ordered level indices, 0-indexed). Pricing: $0.10 per 1M input tokens, no output/cache charges; regional and long-context premiums apply. Speed: OpenAI claims ~10x faster than the Responses API (no published benchmark). Limits: images as base64 data URLs only (max 128 parts), no hosted URLs or file_id; per-question refusals possible. ZDR and HIPAA for eligible customers; US and EU (EEA + Switzerland) regional processing. Interactive request builder and cost estimator on the page. Independent project, not affiliated with OpenAI. Updated 2026-10-08.