Apple Pay in your native app

This document is intented for Apple Pay in your iOS native application. For Apple Pay in your web application please see the web guide.

Integrating Apple Pay

Introduction

This document is designed to help partners seamlessly integrate Apple Pay into their applications.

Prerequisites

• Active account with Apple Developer Program.

• App compliant with Apple's guidelines.

Step-by-Step Integration Process

1. Setting Up Apple Pay in the App

• Enroll in Apple Developer Program: Ensure you have a developer account with Apple.

• Configure Apple Pay in Xcode: Enable Apple Pay capability in your app's project settings.

• Add Merchant ID: Create and configure your merchant ID in the Apple Developer portal.

  1. Go to Apple's Developer Portal and log in to the Member Center to create a new Merchant ID.

  2. Navigate to the Certificates, Identifiers, and Profiles area of the Member Center, and then begin the Register Merchant ID process.

  3. You must then provide this Merchant ID to one of our associates to enable Apple Pay for your merchant.

• Generating the Certificate Signing Request Once you provide Merchant ID to us, you will be provided a CSR to associate with the merchant in your Apple Developer Portal.

  1. In Apple's Developer Portal, click on the Merchant ID and then click "Edit".

  2. Click "Create Certificate".

  3. You are obtaining a CSR file from a Payment Provider so you will not have to create one. Click "Continue" to proceed to the upload page.

  4. Click "Choose File..." and select the CSR file provided by us.

2. Integration with this platform

API Integration

• Integrating APIs: Use our APIs to connect your app with our payment processing system.

  // Example Swift code for integrating the API
  import PayEngine
  
  class ApplePayViewController: UIViewController, PEApplePayDelegate {
      let amount = 1.00
      
      let config = PEConfig(publicKey: "<API Public key")
      let payengine = PayEngine(config: config)
      
      func paymentSheetDidMDismiss() {
          //Handle Payment Sheet dismiss 
      }
      
      func paymentTokenDidReturn(token: String, completion: @escaping (PEApplePayResult) -> Void) {
          print("paymentTokenDidReturn \(token)")
          makePaymentWithToken(token: token, completion: completion)
      }
      
      func paymentTokenNotAvailable() {
          //Handle Payment token not available 
          print("paymentTokenNotAvailable")
      }
      
      //This is just an example of you calling your backend to complete the transaction.
      //Call completion(.success) or completion(.failure) to close the payment sheet
      private func makePaymentWithToken(token: String, completion: @escaping (PEApplePayResult) -> Void) {
          let json: [String: Any] = [
              "merchant_id": MERCHANT_ID,
              "data": [
                  "cardToken": token,
                  "transactionAmount": amount
              ]
          ]
  
          let jsonData = try? JSONSerialization.data(withJSONObject: json)
  
          let url = URL(string: <your-backend-url>)!
          var request = URLRequest(url: url)
          request.httpMethod = "POST"
          request.setValue("Basic " + <your-api-key>, forHTTPHeaderField: "Authorization")
          request.setValue("\(String(describing: jsonData?.count))", forHTTPHeaderField: "Content-Length")
          request.setValue("application/json", forHTTPHeaderField: "Content-Type")
           request.httpBody = jsonData
  
          let task = URLSession.shared.dataTask(with: request) { data, response, error in
              guard let data = data, error == nil else {
                  print(error?.localizedDescription ?? "No data")
                  return
              }
              let responseJSON = try? JSONSerialization.jsonObject(with: data, options: [])
              if let responseJSON = responseJSON as? [String: Any] {
                  print(responseJSON) //Code after Successfull POST Request
                  if let responseData = responseJSON["data"] as? [String: Any] {
                      print("responseData: \(responseData)")
                      completion(.success)
                      return
                  }
              }
              
              completion(.failure)
          }
  
          task.resume()
      }
      
      // Sample UI code
      @IBOutlet weak var stackView: UIStackView!
      
      required init?(coder: NSCoder) {
          super.init(coder: coder)
      }
      
      override func viewDidLoad() {
          payengine.applePay(merchantId: <merchant-id>) { result in
              switch result {
                  
              case .success(let applePay):
                  // register callbacks to this view controller
                  applePay.delegate = self
                  
                  let request = ApplePayPaymentRequest()
                  request.build(paymentItems: [
                      // leave empty or list of PKPaymentSummaryItem
                  ], paymentAmount: self.amount, currencyCode: "USD")
                  DispatchQueue.main.async {
                      if let button = applePay.setupApplePayButton(for: request, type: .checkout) {
                          /// apple pay is available, add the button to your UI
                          self.stackView.addSubview(button)
                      }
                  }
              case .failure(let error):
                  print("Unable to setup apple pay: \(error)")
              }
          }
          
      }
  }

3. Handling Multiple Merchant IDs (MIDs)

• Multiple MIDs: Manage various merchant IDs in your app by following Apple's guidelines.

• Implementation Tips: Ensure your app can switch between MIDs based on the transaction context.