Javascript SDK and discount/coupons/promos

[DKTim]

I am struggling to get "discount" to work in the "breakdown" field when I am creating an order via the Javascript SDK (smart payment buttons).

            // Set up the transaction
            createOrder: function(data, actions) {
                return actions.order.create({
                    purchase_units: [{
                        description: "My awesome product",
                        amount: {
                            currency_code: "USD",
                            value: "4.99",
                            breakdown: {
                                item_total: {
                                    currency_code: 'USD',
                                    value: "3.76"
                                },
                                discount: {
                                    currency_code: "USD",
                                    value: "1.23"
                                }
                            }
                        },
                        custom_id: "ORDER-0001234"
                    }],
                    application_context:  { 
                        shipping_preference: "NO_SHIPPING"
                    }

                });
            },

The error I see is "AMOUNT_MISMATCH".


According to the API documentation
https://developer.paypal.com/docs/api/orders/v2/#definition-amount_breakdown 
And this Github ticket
https://github.com/paypal/paypal-checkout-components/issues/1016

The functionality should be available since 1 April 2020.

Any suggestions on what I am doing wrong?

[DKTim · Accepted solution]

Rubber ducking really is a thing. I just managed to solve my own problem, which was that the line-item is the original price (4.99) and the amount value should be the original price (4.99) minus the discount (1.23), which is 3.76

This code works:

            // Set up the transaction
            createOrder: function(data, actions) {
                return actions.order.create({
                    purchase_units: [{
                        description: "My awesome product",
                        amount: {
                            currency_code: "USD",
                            value: "3.76",
                            breakdown: {
                                item_total: {
                                    currency_code: 'USD',
                                    value: "4.99"
                                },
                                discount: {
                                    currency_code: "USD",
                                    value: "1.23"
                                }
                            }
                        },
                        custom_id: "ORDER-0001234"
                    }],
                    application_context:  { 
                        shipping_preference: "NO_SHIPPING"
                    }

                });
            },

  

And for anyone else wanting to know how to get discounts working for subscriptions, you are able to specify some plan details to override the specified plan:

            createSubscription: function(data, actions) {
                return actions.subscription.create({
                    /* Creates the subscription */
                    plan_id: 'MY PLAN ID',
                    custom_id: "ORDER-00001234",
                    plan: {
                        billing_cycles: [
                        {
                            frequency: {
                                interval_unit: "MONTH",
                                interval_count: 1
                            },
                            tenure_type: "REGULAR",
                            sequence: "1",
                            pricing_scheme: {
                                fixed_price: {
                                    value: "10",
                                    currency_code: "USD"
                                }
                            }
                        }]
                    },
                    application_context:  { 
                        shipping_preference: "NO_SHIPPING"
                    }
                });
            },

See: https://developer.paypal.com/docs/api/subscriptions/v1/#subscriptions_create

An inline plan object to customise the subscription. You can override plan level default attributes by providing customised values for the subscription in this object.