# Mastercard Gateway Android SDK source: https://developer.mastercard.com/mastercard-gateway/documentation/integrations-types/mobile-integration/integrate-mobile-payments/mc-gw-andriod-sdk/index.md ## Installation {#installation} This SDK is packaged as a maven repository. It should be unzipped to a location in your project, and added as a repository in your projects `build.gradle` file. 1. From your Merchant Admin portal, download the latest version of the SDK in a zip file format. For more information about downloading the SDK, see [Mobile SDK Integration](https://developer.mastercard.com/mastercard-gateway/documentation/integrations-types/mobile-integration/integrate-mobile-payments/mob-sdk-int/index.md). 2. Unzip this file in the root directory of your Android project. (For example, \~/my-android- project/gateway- repo) 3. Add a reference to this local repository in your project's `build.gradle` file. ```groovy // build.gradle allprojects { repositories { mavenCentral() google() // Gateway Android SDK repo maven { url "$rootDir/gateway-repo" } } } ``` 4. In your app modules build.gradle file, include the Gateway SDK as a dependency. Warning: Replace 'X.X.X' with the current version number. ```groovy // app/build.gradle dependencies { implementation 'com.mastercard.gateway:Mobile_SDK_Android:X.6X.X' // Replace with the latest version } ``` The `Mobile_SDK_Android` folder contains a maven-metadata.xml file that has information to build the implementation reference for the library. The implementation gradle format is implementation `::` ## Initialize the SDK {#initialize-the-sdk} Initialize the Android SDK before using it. It is recommended to perform this operation in your custom Application class in the `onCreate()` method. Warning: Contact [your payment service provider](mailto:gateway-support@mastercard.com) to know your gateway region. ```java // CustomApplication.kt override fun onCreate() { super.onCreate() // init Gateway SDK GatewaySDK.initialize ( this, "YOUR_MERCHANT_ID", "Your Merchant Name", "{{host}}", "Your gateway region", callback ) } ``` ### Session overview {#session-overview} The Gateway SDK flow is based around the concept of a session. A session is a temporary container for any request fields and values of operations that reference a session. For more information, see the [Payment Session](https://developer.mastercard.com/mastercard-gateway/documentation/integrations-types/hosted-session/integrate-hosted-session/create-payment-session/index.md) documentation. #### Key benefits {#key-benefits} * Reduces PCI compliance costs as you do not handle or store any payment details. * Eases integration as you do not need to directly handle the values for the request fields stored in a session. * Reduces internal fraud as your staff have limited access to payer's details. * Allows you to update the request fields and values stored against a session. This is useful when a credit card expires or other details of a payer change. * Allows you to retrieve the request fields and values contained in a session by specifying the session identifier. ### Create a session {#create-a-session} Create a session with the gateway to initiate the payment flow on a mobile device. * Two API calls must be made to prepare this session for mobile transactions. * These calls are secured by an API password and thus need to be called from your private server. | Request Parameter | Example | |-----------------------|---------| | `authenticationLimit` | 25 | ### Update the session {#update-the-session} | Request Parameter | Existence | Example | |---------------------------------|-----------|---------------------| | `order.id ` | Required | your-order-id | | `order.amount` | Required | 1.23 | | `order.currency` | Required | AUD | | `authentication.acceptVersions` | Required | 3DS2 | | `authentication.channel` | Required | PAYER_APP | | `authentication.purpose` | Required | PAYMENT_TRANSACTION | Warning: To authenticate the payer, the Session API fields must be loaded into the session before the call is made in the SDK. The API design determines how and when they are loaded into the session. Once a session is created on your server, you should 1. return the session information back to the mobile app, and 2. create an instance of the Session object. ```swift // example val session = Session( id = "your-session-id", amount = "1.23", currency = "USD", apiVersion = "100", // API version used to create the session orderId = "your-order-id" // must match order id used on your server ) ``` Warning: The apiVersion needs to be the same for the whole transaction lifecycle, from Session creation to final payment. ## Collecting card information {#collecting-card-information} The SDK method to `updateSession` is optional to use but is recommended to help with merchant server PCI scope. However, the card and token information can be loaded through a different API design and must be present in the session before the call is made in the SDK to authenticate the payer. ### Manual card entry {#manual-card-entry} Pass the information directly to the gateway using an existing Session ID. ```java // The GatewayMap object provides support for building a nested map structure using key-based dot(.) notation. // Each parameter is similarly defined in your online integration guide. val request = GatewayMap() .set("sourceOfFunds.provided.card.nameOnCard", nameOnCard) .set("sourceOfFunds.provided.card.number", cardNumber) .set("sourceOfFunds.provided.card.securityCode", cardCvv) .set("sourceOfFunds.provided.card.expiry.month", cardExpiryMM) .set("sourceOfFunds.provided.card.expiry.year", cardExpiryYY) GatewayAPI.updateSession(session, request, callback) ``` ### Tokenization {#tokenization} The SDK provides support to update a session with card information, and you can use that Session to perform several operations with the gateway. Tokenization provides a way to retain a card on file and can be performed on your server with a valid Session. Follow these steps to use the mobile SDK to help creating a card token. 1. Create and Update a Session using the SDK. 2. Update the session with the customers card details through the Gateway `SDK.GatewayAPIupdateSession` method. 3. Return the Session ID to your server and call the Create or Update Token method on the gateway with your private API credentials. 4. A token ID is returned and can be retained on your servers as a card-on-file. For more information about Tokenization, see the [Create or Update Token](https://developer.mastercard.com/mastercard-gateway/documentation/api-reference/v100/rest/api-ops/index.md#tokenization) documentation. ## Google Pay {#google-pay} The Gateway SDK includes a helper utility, called GooglePayHandler, for collecting card information from a Google Pay wallet. ### Configuration {#configuration} To enable Google Pay support within your app, see the [Google Pay](https://developers.google.com/pay/api/android/overview) documentation. These instructions should guide you on how to: * set up the Google Pay API * request payment information from the Google wallet * incorporate the button in your layout, and * handle the response from the Google Pay API. Since Google Pay integration is optional with the Gateway SDK, you must provide the appropriate play services dependency. ```groovy implementation 'com.google.android.gms:play-services-wallet:X.X.X' ``` The gateway is integrated with Google Pay as a `PAYMENT_GATEWAY` type. To request encrypted card information from Google Pay. 1. use the valid name mpgs in your request, and 2. replace `YOUR_MERCHANT_ID` with the merchant ID that you use on the gateway. ```java val tokenizationSpecification = JSONObject().apply { put("type", "PAYMENT_GATEWAY") put("parameters", JSONObject().apply { put("gateway", "mpgs") put("gatewayMerchantId", "YOUR_MERCHANT_ID") }) } ``` ### Request wallet information {#request-wallet-information} Use the `GooglePayHandler` to launch the Google Pay wallet with your constructed payments client and request data. ```java // YourActivity.kt fun googlePayButtonClicked() { try { val request = PaymentDataRequest.fromJson(paymentDataRequest.toString()) // Use the Gateway convenience handler for launching the Google Pay flow GooglePayHandler.requestData(this, paymentsClient, request) } catch (e: JSONException) { Toast.makeText(this, "Could not request payment data", Toast.LENGTH_SHORT).show() } } ``` ### Handle wallet response {#handle-wallet-response} The Gateway SDK offers a Google Pay lifecycle handler for convenience. You may implement the provided Google Pay callback and use the result handler within your activity. This eliminates the need to manually handle the Google Pay activity results and delegates the important transaction steps to the callback methods. ```java // YourActivity.kt override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) { // Handle the Google Pay response if (GooglePayHandler.handleActivityResult(requestCode, resultCode, data, callback)) { return } super.onActivityResult(requestCode, resultCode, data) } val googlePayCallback = object : GooglePayCallback { override fun onReceivedPaymentData(paymentData: JSONObject) { try { val description = paymentData .getJSONObject("paymentMethodData") .getString("description") Log.d(MyGooglePayCallback::class.java.simpleName, "ReceivedPaymentData: $description") } catch (e: Exception) { // Handle exception Log.e(MyGooglePayCallback::class.java.simpleName, "Error parsing payment data", e) } handleGooglePayData(paymentData) } override fun onGooglePayCancelled() { // Handle cancellation Log.d(MyGooglePayCallback::class.java.simpleName, "Google Pay was cancelled") } override fun onGooglePayError(status: Status) { // Handle error Log.e(MyGooglePayCallback::class.java.simpleName, "Google Pay error: ${status.statusMessage}") } } ``` ### Update a session with the payment token {#update-a-session-with-the-payment-token} Update a session with the gateway once you receive payment data from Google Pay. ```java fun handleGooglePayData(paymentData: JSONObject) { val token = paymentData .getJSONObject("paymentMethodData") .getJSONObject("tokenizationData") .getString("token") val request = GatewayMap() .set("sourceOfFunds.provided.card.devicePayment.paymentToken", token) GatewayAPI.updateSession(session, request, callback) } ``` ## Payer authentication {#payer-authentication} ### EMV 3-D Secure {#emv-3-d-secure} EMV 3-D Secure or EMV 3-D Secure authentication is designed to protect online purchases against credit card fraud by allowing you to authenticate the payer before submitting an Authorization or Pay transaction. The EMV 3-D Secure, also known as 3DS2 in the gateway, is the new version designed to enhance security in online purchases while providing frictionless checkouts to payers who are considered low risk by the Access Control Server (ACS). The ACS may determine the risk using information provided by the merchant, device fingerprinting, or previous interactions or both, with the payer. The ACS subjects the payer to a challenge (for example, entering a PIN) only where additional verification is required to authenticate the payer, thereby providing increased conversion rates. Supported authentication schemes include Mastercard Identity Check, Visa Secure, and American Express SafeKey. Authentication within the mobile SDKs is limited to 3DS2 only. If 3DS2 is not available, the authentication will not proceed. However, you can still proceed with the payment if the gateway recommends you do so. For more information about EMV 3-D Secure Authentication, see the [EMV 3-D Secure Authentication](https://developer.mastercard.com/mastercard-gateway/documentation/security-and-fraud/authentication/3d-secure-auth/index.md) documentation. ### Authentication details {#authentication-details} The embedded mobile SDK collects device metrics to send to the gateway along with your transaction information when you perform mobile SDK authentication, that is, verify the identity of a cardholder in a mobile app. Provide as much information as possible about the payer and the transaction to increase the likelihood of the authentication being successful. This additional information can be added to your session with an [Update session](https://developer.mastercard.com/mastercard-gateway/documentation/integrations-types/mobile-integration/integrate-mobile-payments/mc-gw-andriod-sdk/index.md#update-the-session) request. | Parameter | Existence | Description | |------------------------------------|-----------|-------------------------------------------------------------------------------| | `order.merchantCategoryCode` | Optional | Same as the code in your merchant profile | | `billing.address parameter group` | Optional | It is strongly recommended you include this in your request whenever possible | | `shipping.address parameter group` | Optional | It is recommended you include this in your request whenever possible | | `customer parameter group` | Optional | It is recommended you include this in your request whenever possible | Warning: The device parameter group as seen in the documentation is only relevant for browser-based payments. It should not be used for mobile based payer authentications. These metrics help the system to determine how or if to authenticate the cardholder. During authentication, the user can expect to experience one of two flows: 1. Frictionless: The ACS has collected enough information about the cardholder to authenticate them. No other action is needed by the user. 2. Challenge: The ACS requires the cardholder complete an additional authentication step which is to enter a onetime-password, login to their issuing bank, and so on. The embedded mobile SDK handles displaying a native device interface for this challenge. The UI for these screens can be customized by passing UI Customization params into the Gateway SDK during initialization. For more information, see [Authenticate Payer](https://developer.mastercard.com/mastercard-gateway/documentation/api-reference/v100/rest/api-ops/index.md#authentication) documentation. Warning: The parameter group for `authentication.PSD2.exemption` is currently not supported in the SDK.
### Perform authentication {#perform-authentication} Payer authentication is considered a transaction on its own in the gateway, and therefore needs a unique transaction ID. If you are collecting payment for an order, you can * correlate a payment and an authentication transaction by using the same order ID for each transaction. * each transaction is displayed as a separate transaction in the gateway web portal, such as UUID. ```java AuthenticationHandler.authenticate( activityContext, session, "your-auth-transaction-id", callback ) ``` Warning: The `your-auth-transaction-id` is a unique identifier for this transaction which distinguishes it from any other transaction on the order. This is needed as the gateway uses the `your-auth-transaction-id` to look up the authentication results that it stored when you asked the SDK to authenticate the payer. The gateway then passes the required information to the acquirer for the pay request. ### Interpret the response {#interpret-the-response} The authenticate method returns an `AuthenticationResponse` object that contains: * important information about the outcome, and * actions performed during the operation. The most important field to consume is `response.recommendation`. It may contain the value PROCEED or DO_NOT_PROCEED. * PROCEED: Indicates "OK to continue with a payment or authorization". * DO_NOT_PROCEED: Indicates something failed during the authentication operation. The `AuthenticationError` object can be used to determine more. From Mastercard Gateway API version 70 and later, you can get the following errors: * `AuthenticationError.recommendation_ResubmitWithAlternativePaymentDetails`: Indicates that you should ask the payer for alternative payment details. For example, a new card or another payment method, and resubmit the request with the new details. * `AuthenticationError.recommendation_AbandonOrder`: Indicates the payment service provider, scheme, or issuer require you to abandon the order. * `AuthenticationError.recommendation_DoNotProceed`: Indicates that the gateway fails the request, but there is no way for this transaction to succeed. ```java AuthenticationHandler.authenticate( activityContext, session, "your-auth-transaction-id" ) { response -> when (response.recommendation) { AuthenticationRecommendation.PROCEED -> { // Continue to payment/authorization } AuthenticationRecommendation.DO_NOT_PROCEED -> { if (response.error != null) { if (response.error is AuthenticationError.RecommendationResubmitWithAlternativePaymentDetails) { // Authentication not successful, re-enter card details } } else { // Authentication not successful } } } } ``` If the authentication fails, you can examine the `response.error`, for more information about the cause.