Apple Pay

First, you need a Stripe account. Register now.

Server-side

This integration requires endpoints on your server that talk to the Stripe API. Use the official libraries for access to the Stripe API from your server:

# Available as a gem
sudo gem install stripe

# If you use bundler, you can add this line to your Gemfile
gem 'stripe'

Client-side

The Stripe iOS SDK is open source, fully documented, and compatible with apps supporting iOS 13 or above.

Configure the SDK with your Stripe publishable key on app start. This enables your app to make requests to the Stripe API.

import UIKit
import StripeApplePay

@main
class AppDelegate: UIResponder, UIApplicationDelegate {

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        StripeAPI.defaultPublishableKey = "pk_test_YVzIqUTwiCYcEXO1DPqDrM98"
        // do any other necessary launch configuration
        return true
    }
}

Obtain an Apple Merchant ID by registering for a new identifier on the Apple Developer website.

Fill out the form with a description and identifier. Your description is for your own records and you can modify it in the future. Stripe recommends using the name of your app as the identifier (for example, merchant.com.{{YOUR_APP_NAME}}).

Create a certificate for your app to encrypt payment data.

Go to the iOS Certificate Settings in the Dashboard, click Add new application, and follow the guide.

Download a Certificate Signing Request (CSR) file to get a secure certificate from Apple that allows you to use Apple Pay.

One CSR file must be used to issue exactly one certificate. If you switch your Apple Merchant ID, you must go to the iOS Certificate Settings in the Dashboard to obtain a new CSR and certificate.

Add the Apple Pay capability to your app. In Xcode, open your project settings, click the Signing & Capabilities tab, and add the Apple Pay capability. You might be prompted to log in to your developer account at this point. Select the merchant ID you created earlier, and your app is ready to accept Apple Pay.

[xcode.a701d4c1922d19985e9c614a6f105bf1.png]

Enable the Apple Pay capability in Xcode

Before displaying Apple Pay as a payment option in your app, determine if the users device supports Apple Pay and that they have a card added to their wallet:

import StripeApplePay
import PassKit

class CheckoutViewController: UIViewController, ApplePayContextDelegate {
    let applePayButton: PKPaymentButton = PKPaymentButton(paymentButtonType: .plain, paymentButtonStyle: .black)

    override func viewDidLoad() {
        super.viewDidLoad()
        // Only offer Apple Pay if the customer can pay with it
        applePayButton.isHidden = !StripeAPI.deviceSupportsApplePay()
        applePayButton.addTarget(self, action: #selector(handleApplePayButtonTapped), for: .touchUpInside)
    }

    // ...continued in next step
}

When the user taps the Apple Pay button, call StripeAPI paymentRequestWithMerchantIdentifier:country:currency: to create a PKPaymentRequest.

Then, configure the PKPaymentRequest to display your business name and the total. You can also collect information like billing details or shipping information.

See Apples documentation for full guidance on how to customize the payment request.

func handleApplePayButtonTapped() {
    let merchantIdentifier = "merchant.com.your_app_name"
    let paymentRequest = StripeAPI.paymentRequest(withMerchantIdentifier: merchantIdentifier, country: "US", currency: "USD")

    // Configure the line items on the payment request
    paymentRequest.paymentSummaryItems = [
        // The final line should represent your company;
        // it'll be prepended with the word "Pay" (that is, "Pay iHats, Inc $50")
        PKPaymentSummaryItem(label: "iHats, Inc", amount: 50.00),
    ]
    // ...continued in next step
}

Create an STPApplePayContext instance with the PKPaymentRequest and use it to present the Apple Pay sheet:

func handleApplePayButtonTapped() {
    // ...continued from previous step

    // Initialize an STPApplePayContext instance
    if let applePayContext = STPApplePayContext(paymentRequest: paymentRequest, delegate: self) {
        // Present Apple Pay payment sheet
        applePayContext.presentApplePay(on: self)
    } else {
        // There is a problem with your Apple Pay configuration
    }
}

Apple requires that user gestures trigger the Apple Pay modal (for example, clicking a button or interacting with the form). Make sure your code adheres to the following:

• Invoke the payment sheet directly with a user activation event.
• Add the code for the payment sheet at or near the top of your user gesture event handler, before any asynchronous or long-running code.
• Set a reasonable time limit to call confirmPayment after the user gesture.

Server-side

Make an endpoint that creates a PaymentIntent with an amount and currency. Always decide how much to charge on the server side, a trusted environment, as opposed to the client side. This prevents malicious customers from choosing their own prices.

curl https://api.stripe.com/v1/payment_intents \
  -u sk_test_wU7nrJCZspk1NPDxiQgAF05q: \
  -d "amount"=1099 \
  -d "currency"="usd"

Client-side

extension CheckoutViewController {
    func applePayContext(_ context: STPApplePayContext, didCreatePaymentMethod paymentMethod: StripeAPI.PaymentMethod, paymentInformation: PKPayment) async throws -> String {
        let clientSecret = try await ... // Retrieve the PaymentIntent client secret from your backend (see Server-side step above)
        // Return the client secret or throw an error
        return clientSecret
    }

    func applePayContext(_ context: STPApplePayContext, didCompleteWith status: STPApplePayContext.PaymentStatus, error: Error?) {
          switch status {
        case .success:
            // Payment succeeded, show a receipt view
            break
        case .error:
            // Payment failed, show the error
            break
        case .userCancellation:
            // User canceled the payment
            break
        @unknown default:
            fatalError()
        }
    }
}

Troubleshooting

If youre seeing errors from the Stripe API when attempting to create tokens, you most likely have a problem with your Apple Pay Certificate. Youll need to generate a new certificate and upload it to Stripe, as described on this page. Make sure you use a CSR obtained from your Dashboard and not one you generated yourself. Xcode often incorrectly caches old certificates, so in addition to generating a new certificate, Stripe recommends creating a new Apple Merchant ID as well.

If you receive the error:

You havent added your Apple merchant account to Stripe

its likely your app is sending data encrypted with a previous (non-Stripe) CSR/Certificate. Make sure any certificates generated by non-Stripe CSRs are revoked under your Apple Merchant ID. If this doesnt resolve the issue, delete the merchant ID in your Apple account and re-create it. Then, create a new certificate based on the same (Stripe-provided) CSR that was previously used. You dont need to upload this new certificate to Stripe. When finished, toggle the Apple Pay Credentials off and on in your app to ensure they refresh properly.