Integration with the Native OTP Assist mobile SDK in 4 steps:

1.Include the SDK in your app project (Mandatory Step)

The Native OTP SDK is offered via CocoaPods. To add the SDK to your app project, include the SDK framework in your podfile.

// make sure to add below-mentioned line to use dynamic frameworksuse_frameworks!​
// Add this to include our SDK
pod 'PayUIndia-NativeOtpAssist' 

Install dependency using pod installcommand in terminal

Next, add the following imports in the class where you need to initiate a payment

import PayUNativeOtpAssist

Test Merchant key/salt for the production environment: ol4Spy/J0ZXw2z9

Test Merchant key/salt for the test environment: gtKFFx/eCwWELxi


Min iOS Version: 11

Please set "Excluded Architectures" to "arm64" in the Build Settings of your project to run in Simulator.


In order to receive all the crashes related to our SDKs, add the below-mentioned line your AppDelegate's didFinishLaunchingWithOptions.


Swift Package Manager Integration

You can integrate PayUIndia-NativeOtpAssist with your app or SDK in two ways:

  1. Via Xcode - Go to File-> Add Package->

  2. Via Package.Swift - Add below line in Package.swift dependencies

.package(name: "PayUIndia-NativeOtpAssist", url: "", from: "2.0.0")

2. Set up the payment hashes (Mandatory Step)

A detailed document is present here.

You need to implement a payment hash.

Every transaction (payment or non-payment) needs a hash by the merchant before sending the transaction details to PayU. This is required for PayU to validate the authenticity of the transaction. This should be done on your server.

Payment Post Data

To initiate a payment, your app will need to send transactional information to the Checkout Pro SDK. To pass this information, build a payment parameter object as

TransactionId can't have a special character and not more than 25 characters.

let paymentParam = PayUPaymentParam(key: <#T##String#>,
                                    transactionId: <#T##String#>,
                                    amount: <#T##String#>,
                                    productInfo: <#T##String#>,
                                    firstName: <#T##String#>,
                                    email: <#T##String#>,
                                    phone: <#T##String#>,
                                    surl: <#T##String#>,
                                    furl: <#T##String#>,
                                    environment: <#T##Environment#> /*.production or .test*/)

paymentParam.hashes = PayUHashes()
paymentParam.hashes?.paymentHash = <#T##SHA512 HashString#>
let ccdc = CCDC()
ccdc.cardNumber = <#T##String#>
ccdc.expiryYear = <#T##String#>
ccdc.expiryMonth = <#T##String#>
ccdc.cvv = <#T##String#>
ccdc.txnS2SFlow = <#T##String#> //"4" for transactions on native otp assist
ccdc.nameOnCard = <#T##String#>
ccdc.shouldSaveCard = <#T##String#>
paymentParam.paymentOption = ccdc
paymentParam.userCredential = <#T##String#> // For saving and fetching user’s saved card

Use Core Sdk library to generate payment postdata.

Check here for Payment parameter definitions.

3.Initiate Payment

Initialize the Native OTP Assist SDK by providing the PayUOtpAssistConfig object having postdata and reference to the PayUOtpAssistCallback to listen to the SDK events.
                    parentVC: self,
                    paymentParam: paymentParam,
                    config: <#T##PayUOtpAssistConfig?#>,
                    delegate: self

Initiate payment must be on Main Thread.


List of the callback function provided by PayUOtpAssistDelegate class:

  1. func onPaymentSuccess(merchantResponse: String?, payUResponse: String?)- Called when payment succeeds.

  2. func onPaymentFailure(merchantResponse: String?, payUResponse: String?)- Called when payment fails.

  3. func onError(errorCode: String?, errorMessage: String?)- Called when we got some error where,

    • errorCode : Error Code

    • errorMessage : Error Description

  4. func onPaymentCancel(isTxnInitiated: Bool)- called when user cancel the transaction.

  5. func shouldHandleFallback(payUAcsRequest: PayUAcsRequest) -> Bool - It's an optional callback, override when you want to handle the Bank page redirection flow. You just need to change the return value to false. You can also open CustomeBrowser in fallback scenarios. Below is the code snippet to open the CustomBrowser.

func shouldHandleFallback(payUAcsRequest: PayUAcsRequest) -> Bool {
        if shouldHandleFallback {   // Return 'true', when merchant doesn't want to handle fallback scenarios
            return true
        // Set the merchantKey and transactionId
        PUCBConfiguration.getSingletonInstance()?.merchantKey = key
        PUCBConfiguration.getSingletonInstance()?.transactionId = payUAcsRequest.transactionId ?? ""

        if let issuerUrl = payUAcsRequest.issuerUrl, let issuerPostData = payUAcsRequest.issuerPostData, !issuerUrl.isEmpty {
            // Set the issuerUrl and issuerPostData to open in WebView
            PUCBConfiguration.getSingletonInstance()?.paymentPostParam = issuerPostData
            PUCBConfiguration.getSingletonInstance()?.paymentURL = issuerUrl
        if let acsTemplate = payUAcsRequest.acsTemplate {
            // Set the acsTemplate to open in WebView
            PUCBConfiguration.getSingletonInstance()?.htmlData = acsTemplate

        // Open CB
          let webVC = try PUCBWebVC(
                    postParam: PUCBConfiguration.getSingletonInstance()?.paymentPostParam ?? "=",
                    url: URL(string: PUCBConfiguration.getSingletonInstance()?.paymentURL ?? ""),
                    merchantKey: self.key
                webVC.cbWebVCDelegate = self
                self.navigationController?.setNavigationBarHidden(false, animated: false)
                self.present(webVC, animated: true)
            } catch let error {
                self.onError(errorCode: "0", errorMessage: error.localizedDescription)

        return false

You will get PayUAcsRequest on shouldHandleFallback() callback. whether you will get issuerUrl and issuerPostData or acsTemplate on PayUAcsRequest acsTemplate is the Html string that you need to load to the Webview.

PayUAcsRequest field



It's the Bank/ACS page Url.


You need to load issuerUrl to the Webview

along with this issuerPostdata string.

Ex: webView.postUrl(issuerUrl, issuerPostData.toByteArray())


If issuerUrl is empty, you need to load acsTemplate to the Webview.

Ex: webView.loadData(acsTemplate, "text/html", "UTF-8");

Error codes and their description.

   - ErrorCode: Description

   - 1001     : No Internet
   - 1002     : Network timeout, please verify with your server.
   - 1003     : Gateway timeout, please verify with your server.
   - 1005     : Something went wrong , please verify with your server.
   - 1006     : Bank page timed out, please verify with your server.

Verify the transaction

Once you get the response from SDK, make sure to confirm it with the PayU server. It is recommended to implement the PayU backend verify call from your backend.

Implementation of PayU verify API

Since you already have the txnID (Order ID generated at your end) value for such cases, you simply need to execute the verify_payment API with the necessary input parameters.

The output would return you the transaction status in "status" key and various other parameters also.


curl --location --request POST '{{Url}}' \
--header 'Content-Type: application/x-www-form-urlencoded' \
--data-urlencode 'key={merchantKey}' \
--data-urlencode 'command=verify_payment' \
--data-urlencode 'hash=c6febddfaaf6986dd8bd982d3769f856ab149e4de92dbad995c8df808ffcfbcb2c227a3fae38b69eb39ad7b6ce4e06e6b12289f70cc500cea5a2cda449c7dcba' \
--data-urlencode 'var1=Txn1234'




Sample Value


In this parameter, you can put all the txnid(Your transaction ID/order ID) values in a pipe-separated form.



This parameter must have the name of the web service.

It must be verify_payment


It's the merchant key that PayU provided you.


This parameter must contain the hash value to be calculated at your end. The string used for calculating the hash is mentioned below: sha512(key|command|var1|salt) sha512 is the encryption method used here.


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