On This Page
Getting Started with the Tap to Pay on Android Solution
Use the information in this section to get started with integrating the Tap to Pay on
Android Solution. When the integration is completed, your application will be ready to
start processing payments. For more information, see Tap to Pay on Android Payment Services.
Configuring the Tap to Pay on Android SDK
Use the information in this section to configure the Tap to Pay on Android SDK.
Configure the Project settings.gradle File
settings.gradle
FileFollow this step to configure your project's
settings.gradle
file.- Add the repository to your project'ssettings.gradlefile.dependencyResolutionManagement { repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS) repositories { mavenCentral() google() exclusiveContent { forRepository { maven { setUrl("https://repo.visa.com/mpos-releases/") } } filter { includeGroup("io.payworks") } } } }
Configure the Project build.gradle File
build.gradle
FileFollow this step to configure your project's
build.gradle
file.- Add the Kotlin Gradle plug-in, which is required to use this solution. Note that Kotlin version 2.1 or later and Android Gradle version 8.2 or later are required.plugins { id("com.android.application") version "8.2.0" apply false id("org.jetbrains.kotlin.android") version "2.1.0" apply false }
Configure the Module build.gradle File
build.gradle
FileFollow these steps to configure your module
build.gradle
file.- In the Android section, add these exclusion rules to your module'sbuild.gradlefile.android { ... packaging { resources { excludes.add("META-INF/*") excludes.add("LICENSE.txt") excludes.add("asm-license.txt") } } }
- In order for the app to support Java 17 features, you must set the compatibility levels.android { ... compileOptions { sourceCompatibility = JavaVersion.VERSION_17 targetCompatibility = JavaVersion.VERSION_17 } kotlinOptions { jvmTarget = "17" } }
- The Tap to Pay on Android Solution library publishes a release build type only. The debug build type is not available, so set thematchingFallbacksfield value torelease.android { ... buildTypes { ... debug { matchingFallbacks.apply { clear() add("release") } } } }
- IMPORTANTStay current with the latest SDK. The SDK repository is continuously updated to make available the six latest versions. When a new version is released, the oldest is removed and can no longer be used for new application builds. Establish a regular process for updating to the newest available SDK version to avoid potential build failures and to ensure that your application runs with the latest features, performance enhancements, and security updates.Add the required Default UI and Tap to Pay on Android libraries to the Dependencies section of your module'sbuild.gradlefile.dependencies { ... // This is the Default UI dependency implementation("io.payworks:paybutton-android:2.110.0") // This is the Tap to Pay dependency implementation("io.payworks:mpos.android.taptophone:2.110.0") }
Update the AndroidManifest.xml File
AndroidManifest.xml
FileTo support a large heap size and ensure the necessary permissions for the Default
UI, update your Follow these steps to update your
AndroidManifest.xml
file. Enabling a larger heap is
essential for scenarios where terminal updates require the handling and transfer of
large volumes of data.WARNING
Do not enable automatic backup in your app's
AndroidManifest
file. The Tap to Pay on Android SDK uses the Android
Keystore to install and store cryptographic keys in your app. Using automatic backup
restores the default encryption preferences and causes a functionality error in the
Tap to Pay on Android SDK.AndroidManifest.xml
file:- Set theandroid:allowBackupattribute tofalseand theandroid:largeHeapattribute totrue.<application ... android:allowBackup="false" android:largeHeap="true" > ... </application>
- Enable the needed permissions for the Default UI.<manifest ... > ... <!-- Needed for Default UI ! --> <uses-permission android:name="android.permission.INTERNET"/> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/> <uses-permission android:name="android.permission.READ_PHONE_STATE"/> ... </manifest>
Configure ProGuard Rules to Enable Obfuscation
Follow these steps to configure ProGuard rules that enable obfuscation.
- To enable obfuscation for any of your build types, define the setting in the relevantbuild.gradlefile for your app.buildTypes { release { isMinifyEnabled = true proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro") } }
- If you are using ProGuard as an obfuscation tool in your app, add these rules to theproguard-rules.profile.# OkHttp -keepattributes Signature -keepattributes *Annotation* -dontwarn com.squareup.okhttp.** -keep class com.squareup.okhttp.* { *; } -dontwarn okio.** # Acceptance Devices -keep class io.mpos.** { *; } -dontwarn io.mpos.** -keep class com.visa.vac.tc.** {*;} -keep class com.nimbusds.jose.** {*;} -keep class org.bouncycastle.** {*;} -keep class retrofit2.** { *; } -keep interface retrofit2.** { *; } -keep class com.visa.auth.** { *; } -dontwarn com.visa.auth.** -keep class androidx.** { *; } # Visa Sensory Branding -keep class com.visa.SensoryBrandingView # Mastercard Sonic Branding -keep class com.mastercard.sonic.BuildConfig {*;}
Installing the Tap to Pay Ready App
The Tap to Pay Ready app must be installed on your Android device to support
PCI-compliant payment processing. This app is a core component of the PCI-Certified
MPoC Solution. For more information, see PCI MPoC Standard Compliance and Transaction Workflow for the PCI-Certified MPoC Solution.
Install the Tap to Pay Ready App
Use one of these options to install the Tap to Pay Ready App on your device:
- Click this Google Play store link to install the app directly on your Android device. No additional set up is required.
- Download the app when prompted during device enrollment. For more information, see Enroll a Device.
Generating a Secret Key for an Existing Merchant ID
You must enter a secret key and MID in the
mposUi
instance that you
create. Use the information in this section to generate a secret key for an existing
merchant ID (MID) through the Business Center
or by submitting a REST API
request.For more information about the
mposUi
instance, see Creating an mposUI Instance.Generate a Secret Key for an Existing Merchant ID in the Business Center
You can generate an secret key for an existing merchant ID (MID) in the
Business Center
. Enter these values in the mposUi
instance that
you create. For more information, see Creating an mposUI Instance. Follow these steps to
generate a secret key for an existing MID in the
Business Center
:- In theBusiness Center, go to the left navigation panel and choosePayment Configuration>Key Management. The Key Management page appears.
- From the Merchant drop-down list, choose the merchant ID for which you want to generate a secret key.
- ClickGenerate Key.
- In the Recommended Key Types list, scroll down and chooseAcceptance Devices Secret Key.
- ClickGenerate Key. The Key Generation page appears.
- ClickGenerate Key. Your MID and secret key appear on the page.
- Click theCopyorDownloadicon to obtain the MID and secret key.
ADDITIONAL INFORMATION
IMPORTANTIf you choose to copy the secret key information instead of downloading it, be sure to save it locally. After you leave theBusiness CenterKey Generation page, you will not be able to retrieve the same secret key again. To obtain a new key, you must restart the key generation process.
Generate a Secret Key for an Existing Merchant ID Using a REST API Request
You can submit a REST API request to generate a secret key for an existing merchant ID
(MID). Enter these values in the
mposUi
instance you create. For more
information, see Creating an mposUI Instance. You must authenticate each request that you send to a
Cybersource
API. In
order to authenticate an API request, you can use a REST shared secret key or a REST
certificate. For more information about authentication requirements, see .Endpoints:
Test:
POST
https://apitest.cybersource.com
/kms/v2/keys-sym-posProduction:
POST
https://api.cybersource.com
/kms/v2/keys-sym-posRequired Fields for Generating a Secret Key for an Existing Merchant ID Using a REST
API Request
- keyInformation.organizationId
REST Example: Generating a Secret Key for an Existing Merchant ID Using a REST API
Request
Request
{ "keyInformation": [ { "organizationId": "transacting_MID" } ] }
Response to a Successful Request
{ "submitTimeUtc": "2023-08-07T13:07:17Z", "status": "ACCEPTED", "keyInformation": [ { "organizationId": "transacting_MID", "externalOrganizationId": "MerchantId", "key": "SecretKey", "keyId": "af922a42-6d2c-41fd-92f7-09d908647de4", "status": "ACTIVE", "expirationDate": "2033-08-07T13:07:17Z" } ] }
Creating an mposUI Instance
Use the information in this section to create and configure an
mposUI
instance.Create an mposUI Instance
mposUI
InstanceBefore starting this procedure, you must have a secret key and a merchant ID (MID) values to
enter in to your
mposUI
instance. For more information, see Generating a Secret Key for an Existing Merchant ID.Create an
mposUI
instance to access the functionality of
the Tap to Pay on Android SDK. Follow these steps to create an
mposUI
instance.- Create anmposUIinstance using thecreatefunction.
- Set themerchantIdfield value to the merchant ID that you obtained.
- Set themerchantSecretfield value to the secret key that you obtained.
- Specify the environment by setting theproviderModefield value toTESTor toLIVE.
- Use theProviderMode.TESTsetting to test your integration without charging a real payment card. Use the merchant ID and secret key you obtained from the test environment.
- Use theProviderMode.LIVEsetting to process live transactions. Use the merchant ID and secret key you obtained from the production environment.
val mposUi = MposUi.create( providerMode = ProviderMode.LIVE, // ProviderMode.TEST merchantId = "MerchantId", merchantSecret = "SecretKey" )
Configure an mposUI Instance
To use the
mposUI
instance with the Tap to Pay on Android SDK, you must
configure the mposUI
instance by creating a
UiConfiguration
instance.Create a UiConfiguration Instance
UiConfiguration
InstanceUse a
UiConfiguration
instance to configure the UI functionality
of the Tap to Pay on Android SDK. You can configure these parameters in the
UiConfiguration
instance that you create:- Configure the accessory as Tap to Phone.
- Configure these Summary screen features:
- Refund a transaction (REFUND_TRANSACTION).
- Send a receipt by email (SEND_RECEIPT_VIA_EMAIL).
- Capture a transaction (CAPTURE_TRANSACTION).
- Retry a failed transaction (RETRY_TRANSACTION).
- Increment a transaction (INCREMENT_TRANSACTION).
- Configure the Summary screen so that it can be skipped (SKIP_SUMMARY_SCREEN) or so that it closes after 5 seconds (CLOSE_AFTER_TIMEOUT). The default setting is to show the Summary screen.
- Configure the signature capture so that it prints on the paper receipt (ON_RECEIPT) or is skipped (NONE). The default setting is on-screen signature capture.
Follow this step to create the
UiConfiguration
instance in your
app:- Create and configure theUiConfigurationinstance.mposUi.configuration = UiConfiguration( terminalParameters = AccessoryParameters.Builder(AccessoryFamily.TAP_TO_PHONE).integrated().build(), summaryFeatures = setOf( SummaryFeature.REFUND_TRANSACTION, SummaryFeature.SEND_RECEIPT_VIA_EMAIL, SummaryFeature.CAPTURE_TRANSACTION, SummaryFeature.RETRY_TRANSACTION, SummaryFeature.INCREMENT_TRANSACTION ) // Use this to skip the summary screen // resultDisplayBehavior = UiConfiguration.ResultDisplayBehavior.SKIP_SUMMARY_SCREEN, // Use this to set signature capture to be on paper receipt // signatureCapture = SignatureCapture.ON_RECEIPT, )
Create a TapToPhoneConfiguration Instance
TapToPhoneConfiguration
InstanceCreate a
TapToPhoneConfiguration
instance to configure the device
enrollment process of the Tap to Pay on Android SDK. You can configure these parameters in the
TapToPhoneConfiguration
instance that you create:- Configure the enrollment process to prompt the merchant to enter the serial number of a previously enrolled device (MANUAL_INPUT). The default setting is to show a list of previously enrolled devices and prompt the merchant to select a device from the list (DEVICE_LIST).
- Configure the Serial Number Confirmation screen to be skipped (SKIP). The default setting is to show the screen (SHOW_WITH_SERIAL_NUMBER).
Follow this step to create and configure the
TapToPhoneConfiguration
instance in your app:- Create and configure the instance.mposUi.tapToPhone.tapToPhoneConfiguration = TapToPhoneConfiguration( serialNumberInputMethod = SerialNumberInputMethod.DEVICE_LIST, confirmationScreenOption = ConfirmationScreenOption.SHOW_WITH_SERIAL_NUMBER )
Customizing the Default User Interface
Use the information in this section to customize the Default UI so that it matches your
brand’s visual identity. The included screenshots highlight several style elements with labels
for reference. Note that not all available style elements are shown. A detailed description of
the style elements follows the screenshots.
Figure:
Tap to Pay on Android Default UI Style Elements

Figure:
Tap to Pay on Android Default UI Style Elements

Figure:
Tap to Pay on Android Default UI Style Elements

- animationStrokeColor
- Stroke or outline color for animations.
- approvedStateColor
- Indicator color that appears for the approved transaction badge and animation.
- cardPresentAnimationStrokeColor
- Overrides theanimationStrokeColorstyle element in the card reader drawing on present-card animations. By default, this element is the same color as theanimationStrokeColorstyle element.
- colorControlActivated
- Color applied to switch controls in their active state.
- colorOnPrimary
- Primary color that appears for the filled button text and animation details.
- colorOnSurface
- Color for text that appears over the content view, transaction status badges text, and outlined button stroke.
- colorPrimary
- Primary color that appears for the filled buttons and animations.
- colorSurface
- Background color that appears for the content view.
- colorSurfaceOnSurface
- Background color for displayed lists such as transaction history.
- contactlessStateActiveColor
- Active indicator color that appears when the contactless interface is ready or when a payment card is tapped on the device.
- contactlessStateErrorColor
- Error indicator color that appears when a problem occurs when the device attempts to read a card on the contactless interface.
- contactlessStateInactiveColor
- Inactive indicator color that appears when the contactless interface is not active.
- declinedErrorStateColor
- Indicator color that appears for these elements:
- Declined transaction badges and animation
- Error transaction badges and animation
- Error dialog boxes
- Input field error messages
- notificationColor
- Alert notification color that appears withPoor connectionandLow batterynotifications. The default color is yellow.
- preAuthorizedStateColor
- Indicator color that appears for the pre-authorized transaction badge.
- smallComponentCornerSize
- Defines the corner radius of the buttons and transaction status badge. Set this element to0dpfor square corners,4dpfor slightly square corners (default), or32dpfor round corners.
- toolBarLogo
- Logo that appears during transaction processing. The image must be rectangular, have the minimum dimensions of 144 x 36 pixels, and a 4:1 ratio.
Customize Style Elements Using a Theme
Follow these steps to customize the Default UI style elements.
- Introduce a new theme to your application that includes theTheme.PayButton2theme as a parent theme.<!-- Paybutton theme --> <style name="Theme.AppTheme.SampleTheme" parent="Theme.PayButton2"> <!-- Text color --> <item name="colorOnSurface">@color/black</item> <!-- Background color --> <item name="colorSurface">@color/white</item> <!-- Contactless indicators --> <item name="contactlessStateActiveColor">@color/dui_green</item> <item name="contactlessStateInactiveColor">@color/dui_light_gray2</item> <item name="contactlessStateErrorColor">@color/dui_red</item> <!-- Transaction status --> <item name="approvedStateColor">@color/dui_green</item> <item name="declinedErrorStateColor">@color/dui_red</item> <!-- Also used for error messages and dialogs --> <item name="preAuthorizedStateColor">@color/dui_dark_gray</item> <!-- Filled buttons and animations primary color --> <item name="colorPrimary">@color/dui_blue</item> <!-- Used over the primary color for text on filled buttons and details on animations --> <item name="colorOnPrimary">@color/dui_white</item> <!-- Corner radius for the buttons and transaction status badges --> <item name="smallComponentCornerSize">4dp</item> <!-- Company logo --> <item name="toolBarLogo">@drawable/logo_140x36</item> <!-- Stroke color for icons and animations --> <item name="animationStrokeColor">@color/dui_black</item> </style>
- Call one of these methods to set the theme:mposUi.themeRes = R.style.Theme_AppTheme_SampleTheme
Customize Style Elements Using a UiConfiguration Instance
UiConfiguration
InstanceUse this customization feature to dynamically change some Default UI style elements while
the app is in use. These style elements can be customized using a
UiConfiguration
instance: - toolbarLogo
- colorScheme(and its sub-elements)
- cornerRadius
UiConfiguration
instance:- Create theUiConfigurationinstance.mposUi.configuration = UiConfiguration( // other UiConfiguration parameters toolbarLogo = "....", colorScheme = UiConfiguration.ColorScheme( colorPrimary = 0xFF1A1F71, colorOnPrimary = 0xFFFFFFFF, colorSurface = 0xFFFFFFFF, colorOnSurface = 0xFF1C1B1B, ), cornerRadius = UiConfiguration.CornerRadius.ROUND )
Enable Dark Mode in the Default User Interface
When the payment device is set to dark mode, the Default UI payment screens automatically
adjust to display darker, high-contrast colors compared to the default light mode settings.
This feature is particularly useful in low-light environments such as restaurants and bars.
By default, the dark mode background color is dark gray (
#121212
). To
customize the background to pure black (#000000
), define a new
Theme.PayButton2
theme in the values-night
resource
folder.For more information about the dark mode setting on Android devices, see the Android documentation.
Follow this step to change dark mode behavior:
- Use this Android method to enforce light or dark mode across your entire application and the Default UI, regardless of the system setting on the device. This example enforces night mode.AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES)
Enabling Device Enrollment
Use the information in this section to enable device enrollment and view the device
enrollment result in the Tap to Pay on Android SDK. The enrollment workflow guides you
through the device enrollment activity.
Enroll a Device
Before starting the device enrollment process, make sure the Tap to Pay Ready
app is installed on the Android device. Download the app using this Google Play Store link. If the app is not
installed before device enrollment, you will be prompted to install it during the
enrollment process. To learn more about the Tap to Pay Ready app, see PCI MPoC Standard Compliance.
Use the information in this
section to enroll a device using the
enrollDevice
activity. This
activity presents a merchant-facing UI that enables users to enroll a new device or
a previously enrolled device by selecting or entering the device’s serial
number.- Use theenrollDeviceactivity to enroll the device.val mposUi: MposUi = ... mposUi.tapToPhone.enrollDevice(activity, requestCode) ... override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) { if (EnrollResultIntent.isEnrollmentSuccessful(resultCode, data)) { onDeviceEnrolled() } super.onActivityResult(requestCode, resultCode, data) }
Step Result
Theenrollactivity returns the result Intent.
Enroll a Previously Enrolled Device
Use the information in this section to enroll a previously enrolled device by using
the
reEnrollDevice
activity. This activity enables you to perform
device re-enrollment through the SDK by supplying a stored serial number. This
streamlined workflow eliminates the need for the merchant to manually select or enter
the serial number during re-enrollment.- Use thereEnrollDeviceactivity to enroll the previously enrolled device.val mposUi: MposUi = ... mposUi.tapToPhone.reEnrollDevice(activity, serialNumber, requestCode) ... override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) { if (EnrollResultIntent.isEnrollmentSuccessful(resultCode, data)) { onDeviceEnrolled() } super.onActivityResult(requestCode, resultCode, data) }
Step Result
Theenrollactivity returns the resultIntent.
View the Device Enrollment Result
After completing device enrollment, use the
enroll
activity or
isDeviceEnrolled
function to view the device enrollment result. The
enroll
activity returns the result Intent
when
the device enrollment process is successful. This example shows the information that
is returned in the result
Intent
:RESULT_CODE: EnrollResultIntent.ENROLMENT_RESULT_CODE (3489523) EXTRA: EnrollResultIntent.ENROLMENT_RESULT_EXTRA (enrolmentResult = deviceEnrolled) EXTRA: EnrollResultIntent.ENROLLMENT_RESULT_EXTRA_SERIAL_NUMBER (serialNumber)
The
isDeviceEnrolled
function returns a true
value
when the device is enrolled or a false
value when not. This example
shows how to use the function:enrollmentstatus = isDeviceEnrolled()