API reference
Updated
Send a model, state and named questions to the decide endpoint to receive structured answers.
Request fields
POST https:// accepts a JSON body with a System Zero API key in the Authorization: Bearer header.
modelsystem-zerofollows the alias. Use an attested pinned version to select a model (Models).state- The text, JSON object or JSON array to evaluate.
questions- Named boolean, choice or score questions, each with its own instructions (Decisions).
session_id- Optional routing affinity hint. It does not create a persistent session.
prompt_cache_key- Optional routing hint used when
session_idis absent.
Send Content-Type: application/json. Add an Idempotency-Key when you need replay protection (Idempotency).
Read the response
A successful request returns HTTP 200. Read each named entry in answers; it can hold an answer or a question refusal. These answer ratios are illustrative.
id- Identifies the decision.
model- The answering model version.
served_by- The answering version, matching
model. answers- Results grouped under the question names from the request.
Answered questions include confidence and calibration_version. See Decisions for the question types, results and question refusals.
Response headers
X-Request-Id- Keep this request identifier when contacting support.
X-RateLimit-Limit- The key's window limit, with
X-RateLimit-RemainingandX-RateLimit-Reset. X-RightNow- Idempotent- Replay truefor a replay;unavailablewhen the settled answer cannot be read.X-Latency-Ms- Response timing.
Server-Timingdescribes gateway stages; neither is a latency guarantee. Cache-Controlno-store. Call the API from a server over HTTPS.
Validation
Use the decide schema. Unsupported fields such as messages, temperature and stream return invalid_request.
Attachments and persistent sessions are held. Read Inputs for the exact input refusals and Sessions for the routing hints.
For a refusal, inspect error.code and error.retryable. Follow the response's retry advice in Errors.