{
  "Header": [
    {
      "status": "Success",
      "request_time": "2026-06-11T13:35:48-04:00",
      "url": "https://aqs.epa.gov/data/api/metaData/fieldsByService?email=test%40aqs.api&key=test&service=list",
      "rows": 2
    }
  ],
  "Data": [
    {
      "field_name": "code",
      "field_description": "A short numberic or character \"code\" used to represent something else in the database.  Used to make data entry easier.  For example, state_code 01 represents Alabama."
    },
    {
      "field_name": "value_represented",
      "field_description": null
    }
  ]
}