currency

ISO 4217 currency code. Required whenever you include value.

window._upstack('track', 'add_to_cart', {
  value: 49.99,
  currency: 'USD'  // USD, EUR, GBP, CAD, etc.
});

Type	Required	Events
string	Yes (when value is set)	Any event with `value`

Common Currency Codes

The monetary value of the event.