Technical integration of iOS UPI SDK with the app

Cocapods integration

Add the following lines into your Podfile

// make sure to add below-mentioned line to use dynamic frameworks
// Add this to include our SDK
pod 'PayUIndia-UPI'

Make UPI Payments

  1. Set environment to test or production. You can also set debugging level to get logs from the SDK

    PayUUPICore.shared.environment = .production
    PayUUPICore.shared.logLevel = .error //Other option is verbose. Logs are disabled by default
  2. Set mandatory payment parameters required for the payment

    do {
    paymentParams = try PayUPaymentParams(
    merchantKey: "smsplus", //Your merchant key for the environment set in step 1
    transactionId: "1iYJfaskjf890", //Your unique ID for this trasaction
    amount: "64999", //Amount of transaction
    productInfo: "iPhone", // Description of the product
    firstName: "Vipin", // First name of the user
    email: "[email protected]", // Email of the useer
    //User defined parameters.
    //You can save additional details with each txn if you need them for your business logic.
    //You will get these details back in payment response and transaction verify API
    //Like, you can add SKUs for which payment is made.
    udf1: "SKU1|SKU2|SKU3",
    //You can keep all udf fields blank if you do not have any requirement to save txn specific data
    udf2: "",
    udf3: "",
    udf4: "",
    udf5: "")
    // Example userCredentials - "merchantKey:user'sUniqueIdentifier"
    paymentParams?.userCredentials = "smsplus:[email protected]"
    // Success URL. Not used but required due to mandatory check.
    paymentParams?.surl = ""
    // Failure URL. Not used but required due to mandatory check.
    paymentParams?.furl = ""
    paymentParams?.phoneNumber = "9123456789" // "10 digit phone number here"
    } catch let error {
    print("Could not create post params due to: \(error.localizedDescription)")
  3. Set callbacks to receive actionable events from SDK

    1. paymentCompletion - You receive the payment response here.

      PayUUPICore.shared.paymentCompletion = { [weak self] result in
      DispatchQueue.main.async { [weak self] in
      guard let self = self else {return}
      self.navigationController?.popToRootViewController(animated: false)
      switch result {
      case .success(let response):
      Helper.showAlert(String(describing: response), onController: self)
      case .failure(let error):
      Helper.showAlert(String(describing: error.rawValue), onController: self)
    2. backPressed - If user has not yet initiated the transaction and she presses back button from the UPI payment options page, this callback is triggered. You can dismiss SDK's UI screen here.

      PayUUPICore.shared.backPressed = {[weak self] in
      self?.navigationController?.popToRootViewController(animated: true)
    3. onEnteringVPA - For validating the VPA entered by the user, we need to hit PayU's validate VPA api. This api needs hash. In this callback, you will get the vpa entered by the user. Use this value to generate required hash. When the hash is received from your server, send us the updated post params with the new hash.

      PayUUPICore.shared.onEnteringVPA = {[weak self] vpa, completion in
      guard let self = self else { return }
      self.paymentParams?.vpa = vpa
      self.fetchHashes(withParams: self.paymentParams!) { result in
      switch result {
      case .success:
      case .failure(let error):
      print("Could not fetch hashes \(error.description)")

  4. Fetch hashes and save them in paymentParams object

    • You need to set hashes property in paymentParams. Hashes authenticates that API request originates from the original source and not from any Man in the middle. Property hashes is of type PayUHashes

    • PayUHashes has 3 properties. Each of these 3 is used for a distinct API call. These 3 properties are defined below:

      1. paymentRelatedDetailsForMobileSDKHash: This is required to get available upi payment options from which payment can be made.

      2. paymentHash: This is required to create transaction at PayU's end.

      3. validateVPAHash: This is required by validateVPA API in upi collect flow to check if provided VPA is registered with a bank account and is active or not. Not required in intent transactions.

    • You need to provide first 2 hashes before asking SDK to initiate the payment. Hashes must be generated only on your server as it needs a secret key (also known as salt). Your app must never contain salt.

    • Please see this documentation to generate hashes on your server.

      • Command and var1 values for generating paymentRelatedDetailsForMobileSDKHash & validateVPAHash are given below

      • Hash for param





        value of userCredentials (You have set it in paymentParams)



        vpa string of your user

  5. After setting value of hashes in paymentParams, call following method of class PayUAPI to get all available payment options to the you, "Merchant" :

    class func getUPIPaymentOptions(withPaymentParams params: PayUPaymentParams,
    completion: @escaping(Result<PayUUPIPaymentOptions, PayUSDKError>) ->() )

    You will get a response of type Result with the value of type PayUUPIPaymentOptions in response's success param. Sample code shown below

    PayUAPI.getUPIPaymentOptions(withPaymentParams: self.paymentParams!, completion: { [weak self] result in
    switch result {
    case .success(let paymentOptions):
    self?.availablePaymentOptions = paymentOptions
    case .failure(let error):
  6. With the PayUUPIPaymentOptions object received above, you can populate relevant UPI options on your checkout screen. As stated at the beginning of this document, you have three options to make payment 1. Intent 2. UPI Collect 3. Fallback for Google Pay

    Inside intent key of PayUUPIPaymentOptions object, you get array of objects of type PayUSupportedIntentApp. These are essentially the apps which are supported by the SDK for intent payments. You can now query the SDK for payment options available for the "Current User" based on factors like if Bank/Payment-Service-Provider(PSP) apps are installed on the current user's device or not.

    public class func canUseIntent(forApp app: PayUSupportedIntentApp,
    withUpiOptions options: PayUUPIPaymentOptions) -> Bool
    public class func canUseUpiCollect(withPaymentOptions options: PayUUPIPaymentOptions) -> Bool
    public class func canUseGpayOmni(withPaymentOptions options: PayUUPIPaymentOptions) -> Bool
    public class func canUseGpayCollect(withPaymentOptions options: PayUUPIPaymentOptions) -> Bool

    Based on your priority and availability of payment options for the current user, you can order the payment options on your checkout page. Note: canUseGpayOmni and canUseGpayCollect methods give you fallback options of Google Pay intent app which have approx 10% more success rate than general UPI collect payments . This means, if your user does not have Google Pay app installed, you can still show Google Pay option on your checkout and we will display these two fallback options upon Google pay selection by the user. Google Pay omni payment option takes user's phone number for UPI collect payment.

  7. If user selects intent app option, you need to create an instance of PayUIntentPaymentVC and following data to it.

    let paymentVC = PayUIntentPaymentVC()
    paymentVC.availableUpiOptions = upiOptions
    paymentVC.paymentApp = app //object of type 'PayUSupportedIntentApp'
    paymentVC.paymentParams = params
    navigationController?.pushViewController(paymentVC, animated: false)
  8. If user selects upi collect option or Google Pay fallback option, you need to create an instance of PayCollectPaymentVC by following code convenience method

    let collectVC = PayCollectPaymentVC()

    Then, you should pass following information for payment processing

    collectVC.paymentParams = params
    collectVC.screenType = type // .upi or .gpayFallback
    collectVC.availablePaymentOptions = upiOptions
    self.navigationController?.pushViewController(collectVC, animated: true)

    After the payment is done, you should get the resonse in your payment completion callback defined above PayUUPICore.shared.paymentCompletion

  9. Add the query schemes in info.plist