{
  "payment": {
    ...
    "cart": {
      "items": [
        {
          "sku”: “product SKU - optional”,
          "vendor": "product vendor/brand - optional",
          "title": "product name - required",
          "variant_title": “product variant name - optional",
          "quantity": <product quantity (int) - required>,
          "unit_price": <product price in cents (int) - optional>,
          "line_price": <unit * quantity price in cents (int) - required>,
          "is_gift": <is product being offered (boolean) - optional>,
          "categories": ["product", "categories", "optional"],
          "url": "product page URL - optional",
          "picture_url": "product picture URL - required",
          "requires_shipping": <whether product is physical (boolean) - optional>,
          "taxes_included": <whether price is taxes included - optional>
        },
        ...
      ],
      "discounts": [  // optional - discounts applied to the purchase
        {
           "title": "marketing campaign name - optional",
           "amount": <discounted amount in cents (int) - required>
         },
         ...
       ]
      },
    ...
  }
}

{
 "payment": {
  // ...
   "custom_data": {
      "scoring": {
         "departure_date": "2021-12-19",     // ISO 8601
         "return_date": "2021-12-22",        // ISO 8601
         "destination_name": "Lisbonne",     // string 
         "destination_country": "PT",        // ISO Alpha-2
         "refund_policy": "refundable",      // string
         "passengers": {
           "adult_count": 2,                 // int
           "children_count": 0,              // int
           "infant_count": 0                 // int
         },
         "hosting": {
           "room_type": "double",            // string
           "nights": 7,                      // int
           "category": 4                     // int
         },
         "flight": {
           "main_departure_company": "AF",   // string max 3 characters
           "departure_airport": "CDG",       // IATA code on 3 characters
           "arrival_airport": "LIS",         // IATA code on 3 characters
           "has_transfers": "false",         // Boolean "true" or "false"
           "round_trip": "true",             // Boolean "true" or "false"
           "travel_class": "economy"         // Should be the best class among the possible values
         },
         "insurance": {
           "name": "Assurance Multirisques", // string  max 150 characters
           "price": 5812                     // int in cents
         },
         "activity": "concert",              // string 
         "loyalty_program": {
           "has_loyalty": "true",            // Boolean "true" or "false"
           "name": "vip"                     // string
         }
      }
   },
  // ...
 }
}