catalog.json

{
    "streams": [
      {
        "tap_stream_id": "expenses",
        "key_properties": [],
        "schema": {
          "properties": {
            "string_field": {
              "type": [
                "null",
                "string"
              ]
            },
            "datetime_field": {
              "format": "date-time",
              "type": [
                "null",
                "string"
              ]
            },
            "integer_field": {
              "type": [
                "null",
                "integer"
              ]
            },
            "double_field": {
              "type": [
                "null",
                "number"
              ]
            }
          },
          "type": [
            "null",
            "object"
          ],
          "additionalProperties": false
        },
        "stream": "expenses",
        "metadata": [
            {
              "breadcrumb": [],
              "metadata": {
                "selected": "true"
              }
            }
          ]
      }
    ]
  }