Returns the complete screener field catalog: the field kinds, the per-field data, the enum universes, the request-side rules, the built-in variables and modifiers, and the POST /screener default response fields.

POST /screener field references are validated against this catalog; its rules object documents how to compose a valid request.

{
  "error": {
    "code": 400,
    "message": "Order quantity must be greater than zero"
  },
  "metadata": {
    "page_number": 1,
    "total_items": 42,
    "total_pages": 5
  }
}