The relevant meta fields in the order object are:

Field	Description
`total`	Total cost of the order, including discounts, shipping, and taxes.
`shipping`	Total shipping costs of the order.
`totalDiscount`	Total discounts of the order. Can be a single order-level field, or as the sum of discounts per line.
`totalTax`	Total tax of the order. Can be a single order-level field, or as the sum of taxes per line.

If you have the breakdown per order line, you can send it in each object on the order.lines list:

Field	Description
`type`	The type of line, useful if you allow applying many discounts or taxes to your order. Possible values: `lineItem`: (default) regular order line item `discount`: discount line, e.g. voucher, promo code, etc. `tax`: tax line, e.g. VAT, IVA, etc.
`quantity`	Count of items per line. Should be "1" if `type` is not `lineItem`.
`unitPrice`	Unit price of the item.
`totalDiscount`	Discount on the item.
`taxAmount`	Tax cost applied to the item.
`taxPercentage`	Tax percentage that applies to the item.
`total`	Total cost of the item, including discount and taxes.

Example

Let's say you have:

Item 1, which costs $10, but has a discount of $1
Item 2, which costs $3 per unit, and you order 2 units
The cost of shipping for the order is $4
A discount of $2 on the shipping (e.g. after a certain amount, your shipping cost is reduced)
A "Voucher 1" of $3 that applies a discount on the entire order
The total tax of $1 that applies to the entire order
The total amount of your order (after including taxes, shipping, and applying discounts) is $15

So what you send as the order meta field to Payrails looks like:

{
  "lines": [
    {
      "type": "lineItem",
      "name": "Item 1",
      "quantity": 1,
      "unitPrice": {
        "currency": "EUR",
        "value": "10"
      },
      "totalDiscount": {
        "currency": "EUR",
        "value": "1"
      }
    },
    {
      "type":"lineItem",
      "name":"Item 2",
      "quantity": 2,
      "unitPrice": {
        "currency": "EUR",
        "value": "3"
      }
    },
    {
      "type":"discount",
      "name":"Voucher 1",
      "quantity": 1,
      "unitPrice": {
        "currency": "EUR",
        "value": "3"
      }
    },
    {
      "type":"discount",
      "name":"Shipping discount",
      "quantity": 1,
      "unitPrice": {
        "currency": "EUR",
        "value": "2"
      }
    }
  ],
  "shipping": {
    "currency": "EUR",
    "value": "4"
  },
  "totalTax": {
    "currency": "EUR",
    "value": "1"
  }
}

📘

If you don't need to specify different taxes or discounts as lines, you can use the totalTax or totalDiscount fields on the order level.

If you have the breakdown of items, you don't need to specify the order.total and lines[*].total, we will calculate it for you.