Structured Output for Answer - Seltz

Released: August 6, 2026 The /answer endpoint now takes a response_format parameter — the same OpenAI-style object /v1/chat/completions accepts. Under a JSON mode, the answer field carries a JSON string conforming to your schema instead of Markdown prose, and citations are returned exactly as before.

Highlights

New response_format parameter — {"type": "json_object"} or {"type": "json_schema", ...}
Citations survive — Inline citations no longer appear in the answer text, but citations[] is still populated
Fails fast — A malformed response_format is rejected with a 400 and not billed
Every tier — Works on seltz-base and seltz-pro, buffered and streaming
Available everywhere — Python SDK 1.7.0, TypeScript SDK 2.5.0, and REST POST /v1/answer

Quick Start

import json

from seltz import Seltz

client = Seltz(api_key="your-api-key")

response = client.answer(
    "Who will be the next CEO of Apple?",
    response_format={
        "type": "json_schema",
        "json_schema": {
            "name": "leadership_change",
            "strict": True,
            "schema": {
                "type": "object",
                "properties": {
                    "successor": {"type": "string"},
                    "effective_date": {"type": "string"},
                },
                "required": ["successor", "effective_date"],
                "additionalProperties": False,
            },
        },
    },
)

change = json.loads(response.answer)
print(change["successor"], change["effective_date"])
# John Ternus 2026-09-01

import { Seltz } from "seltz";

const client = new Seltz({ apiKey: "your-api-key" });

const result = await client.answer({
  query: "Who will be the next CEO of Apple?",
  responseFormat: {
    type: "json_schema",
    json_schema: {
      name: "leadership_change",
      strict: true,
      schema: {
        type: "object",
        properties: {
          successor: { type: "string" },
          effective_date: { type: "string" },
        },
        required: ["successor", "effective_date"],
        additionalProperties: false,
      },
    },
  },
});

const change = JSON.parse(result.answer);
console.log(change.successor, change.effective_date);
// John Ternus 2026-09-01

curl -X POST https://api.seltz.ai/v1/answer \
  -H "x-api-key: $SELTZ_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "query": "Who will be the next CEO of Apple?",
    "response_format": {
      "type": "json_schema",
      "json_schema": {
        "name": "leadership_change",
        "strict": true,
        "schema": {
          "type": "object",
          "properties": {
            "successor": {"type": "string"},
            "effective_date": {"type": "string"}
          },
          "required": ["successor", "effective_date"],
          "additionalProperties": false
        }
      }
    }
  }'

Get Started

View the answer endpoint documentation