Jumpseller Javascript API - Count Products in Cart

// run in console for a Simple Product (without Product Variants):
// Jumpseller.addProductToCart(12345, 1, {}, {callback: addToCartCallback});
<script type="text/javascript">

	function addToCartCallback(data) {    
    var sum = 0; // num of individual products in the cart.
    $.each( data.products, function( index, product ){
      sum += product.qty;
		});
    console.log('cart products sum:');
    console.log(sum);
	}
</script>