Passing discount code in Orders API on Shopify - rest

Question

I have been trying to develop an app that takes an order on Shopify on a different channel. I successfully placed an order through the API but I am not able to include the discount code along with the order. The JSON object for the POST data is as below:
{
order: {
email : request.params.order.email, // string
financial_status : 'pending', // string
send_receipt : true, // boolean
send_fulfillment_receipt : false, // boolean
note : request.params.order.note, // string
discount_codes : [], // supposed to be an array of Object| Problem here,
line_items : request.params.order.line_items, // array
customer : request.params.customer, // JSON object
billing_address : request.params.order.billing_address, // JSON object
shipping_address : request.params.order.shipping_address // JSON object
}
}
According to the documentation, the discount_codes is like this -
Applicable discount codes that can be applied to the order. If no codes exist the value will default to blank. A Discount code will include the following fields:
amount: The amount of the discount.
code: The discount code.
type: The type of discount. Can be one of : "percentage", "shipping", "fixed_amount" (default).
What am I doing wrong? My discount_codes is this
[{amount: 100,code:'WELCOME10',type:'percentage'}]
Has anyone done this before?

Answer 1

According to this response from Shopify what you are trying to do is only possible if you pass the total_discounts field along as well with the total amount of the discount you want to apply.
As you will see in this other answer, any codes you have created through Shopify are not available to use with the API and their usage will not be recorded.
I was trying to use this API in order to test the application of different coupon codes that I was generating, but this does not seem to be possible. Apparently, the API was intended for applying discounts that are custom, not ones that already exist in Shopify. This is a frustrating limitation to me.

Answer 2

I successfully create orders with discounts all the time, without ShopifyPlus as that is irrelevant. The data structure that works for me looks like this:
[ { "code": "Shop By PizzleFuzzle 10%", amount: "10", "type": "percentage" } ]

Answer 3

The discount object is available only for Shopify Plus merchants.
Once you are a Shopify Plus merchant, you will be able to create discount codes like that:
POST /admin/discounts.json
{
"discount": {
"discount_type": "percentage",
"value": "15.0",
"code": "balderdash"
}
}
Please see more detailed documentation in the discount object at Shopify API: https://help.shopify.com/api/reference/discount

Answer 4

You should use the value property name instead of amount property name.
e.g.
{value: 100,code:'WELCOME10',type:'percentage'}
and not
{amount: 100,code:'WELCOME10',type:'percentage'}