# Answer typed questions about a state `POST /v1/decide` (operation id `decide`) Answers every question against the shared state in one call. The state is billed once. Requests to an exact GPU model version (for example `dex-1.0.0`) or with `fallback: "never"` are never served by the fallback path; send `fallback: "never"` for content moderation, because the fallback's content filters block that content. A body that repeats a key in any JSON object is rejected with 400 `duplicate_key`. See `docs/spec/dex-v1.md` sections 5 to 7. Authentication: API key as `authorization: Bearer `, scope `decide`. ## Parameters | Name | In | Type | Required | Description | | --- | --- | --- | --- | --- | | `idempotency-key` | header | string | no | Makes retries safe. Within 24 hours, a repeat with the same key and the same body is never charged again. It answers with `idempotent-replayed: true` and the original response: the same `id`, `created`, `model`, answers and `usage`, including the original charge fields. The same key with a different body answers 409. (1 to 255 characters; pattern ^[\x21-\x7E]+$) | | `x-client-request-id` | header | string | no | Your own correlation id, accepted on every public operation. Logged with the request metadata and echoed in the response. A malformed value answers 400 `invalid_header`. (1 to 128 characters; pattern ^[\x21-\x7E]+$) | ## Request body | Field | Type | Required | Description | | --- | --- | --- | --- | | `model` | ModelName | no | An alias such as `dex-1` or an exact version such as `dex-1.0.0`. (default "dex-1"; pattern ^dex-[0-9]+(\.[0-9]+\.[0-9]+)?$) | | `state` | State | yes | The material the questions are about. A string, or JSON whose fields questions can point at with `{{path}}` references. A string of only whitespace, an empty object and an empty array are rejected (empty objects and arrays inside the state are fine). At most 16,384 tokens after rendering. (string: 1 to 65,536 characters, pattern \S; object: at least 1 entries; array of any: at least 1 items) | | `questions` | object | yes | Question id to question. Ids are for your code only and never reach the model. (1 to 32 entries; keys match ^[A-Za-z][A-Za-z0-9_-]{0,63}$) | | `questions.` | Question | no | | | **When `type` is `pick`** | PickQuestion | | | | `questions..type` | string | yes | (always "pick") | | `questions..instructions` | Instructions | yes | What to decide; a string of only whitespace is rejected. May contain `{{path}}` references to state fields, such as `{{ticket.body}}`. (1 to 4,000 characters; pattern \S) | | `questions..criteria` | Criteria | no | Extra rules or definitions the model must apply. May contain `{{path}}` references. A string of only whitespace is rejected. `null` is the same as leaving the field out. (string: 1 to 4,000 characters, pattern \S; array of string: 1 to 20 items) | | `questions..options` | object | yes | Label to description (or null). Key order is kept and shown to the model in that order. Labels have no leading or trailing whitespace and are unique after Unicode NFC normalisation and lower-casing (`Billing` and `billing` are the same label). A description of only whitespace is rejected. (1 to 255 entries; keys match ^\S(.*\S)?$, 1 to 100 characters; values: string \| null, 1 to 1,000 characters, pattern \S) | | `questions..options.