The attributes block

The attributes block contains information on how attributes will be shown both on the popup and the table. Each attribute definition can contain the following properties:

Field name	Description
displayName	Optional. How this attribute will be shown in different parts of the Felt UI.
format	Optional. A numbro object that encodes how numeric fields should be shown.

Example of an attributes block

"attributes": {
  "faa": {
    "displayName": "FAA Code",
    "format": {
      "mantissa": 0,
      "thousandSeparated": true
    }
  },
  "wikipedia": {"displayName": "Wikipedia"}
}

The format object

format accepts any valid numbro format object — common keys include mantissa (decimal places), thousandSeparated, average (compact notation like 1.2M), output ("percent", "currency"), and prefix/postfix. The object is validated by numbro itself, so anything numbro accepts is valid.

Felt adds one extra key on top of numbro: unit, for displaying measurements. Supported values: meter, kilometer, foot, mile, square_meter, hectare, square_kilometer, square_foot, acre, square_mile, and the adaptive auto-distance and auto-area.

"attributes": {
  "parcel_area": {
    "displayName": "Parcel area",
    "format": {"mantissa": 1, "unit": "auto-area"}
  }
}