{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://smklog.com/developers/schemas/problem.schema.json",
  "title": "Problem",
  "type": "object",
  "description": "Every error answer on this host: a stable machine-readable code in error, a sentence for the human in message, and the missing field names when the code is missing_required_fields.",
  "required": [
    "error"
  ],
  "properties": {
    "error": {
      "type": "string",
      "description": "Stable code: invalid_json, invalid_request, missing_required_fields, product_not_recognized, product_url_not_detected, session_failed, session_in_checkout, session_not_found, rate_limited, invalid_token, token_required"
    },
    "message": {
      "type": "string",
      "description": "What went wrong, in a sentence"
    },
    "missing": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "Field names still needed, with missing_required_fields and product_not_recognized"
    },
    "session_id": {
      "type": "string",
      "description": "With session_in_checkout: the session stored under your external_id, whose checkout the human has started"
    },
    "external_id": {
      "type": "string",
      "description": "With session_in_checkout: the external_id you sent"
    }
  },
  "x-provenance": {
    "method": "published",
    "publisher": "SMKlog (SMKLOG-2022 LLC)",
    "source": "https://quote-api.smklog.com/openapi.json",
    "published": "2026-10-19"
  }
}