Google Pay on Android

Accept Google Pay in your Android application using Finix.

This guide details how to get started accepting Google Pay on Android devices using Finix.

Dues and Assessments

We recommend that you pass the address field listed in the steps below. If the address is not passed, you will be charged additional dues and assessments per transaction from the card network.

Step 1: Onboard with Google

Start by familiarizing yourself with the prerequisites for using Google Pay with Finix.

Step 2: Define Google Pay API Version

Declare the version of the Google Pay API that your application uses. The major and minor versions affect the fields expected in each passed object and are included in the response.

Create a base request object that contains properties that are present in all other request objects.

private val baseRequest = JSONObject()
    .put("apiVersion", 2)
    .put("apiVersionMinor", 0)

Step 3: Request a Finix Payment Token

Now that you've defined your Google Pay API Version, request a Finix payment token.

gateway should be set to finix
gatewayMerchantId should be set to the application owner identity or merchant owner identity. To choose the appropriate Identity ID, see Choose Merchant Identifier Value.

private fun gatewayTokenizationSpecification(): JSONObject {
    return JSONObject().apply {
        put("type", "PAYMENT_GATEWAY")
        put("parameters", JSONObject(mapOf(
                "gateway" to "finix",
                "gatewayMerchantId" to "IDxxx")))
    }
}

Step 4: Define Allowed Card Networks

Now that we've requested a Finix payment token, you can set which card networks will be accepted on your site.

private val allowedCardNetworks = JSONArray(listOf(
        "AMEX",
        "DISCOVER",
        "INTERAC",
        "JCB",
        "MASTERCARD",
        "VISA"))

Defining allowedCardAuthMethods sets the authentication methods supported by your site and gateway.

private val allowedCardAuthMethods = JSONArray(listOf(
        "PAN_ONLY",
        "CRYPTOGRAM_3DS"))

For both PAN_ONLY and CRYPTOGRAM_3DS authorization methods, support for 3D Secure is dictated by the processors you integrate with in allowedCardNetworks. Finix accepts both PAN_ONLY and CRYPTOGRAM_3DS authorization methods.

Step 5: Describe Allowed Payment Methods

After you've defined the supported payment card networks, you need to describe your allowed payment methods. You can do this with the following steps:

Combine allowedAuthMethods and allowedCardNetworks to describe how your application supports the CARD payment method.
Extend the baseCardPaymentMethod object and describe the information you expect to be returned to your application. Include a description of the tokenized payment data.

private fun baseCardPaymentMethod(): JSONObject =
    JSONObject()
        .put("type", "CARD")
        .put("parameters", JSONObject()
                .put("allowedAuthMethods", allowedCardAuthMethods)
                .put("allowedCardNetworks", allowedCardNetworks)
                .put("billingAddressRequired", true)
                .put("billingAddressParameters", JSONObject()
                        .put("format", "FULL")
                )
        )
private val cardPaymentMethod: JSONObject = baseCardPaymentMethod()
    .put("tokenizationSpecification", gatewayTokenizationSpecification)

Step 6: Create a PaymentsClient Instance

Create a PaymentsClient instance to interact with the Google Pay API.

fun createPaymentsClient(context: Context): PaymentsClient {
    val walletOptions = Wallet.WalletOptions.Builder()
        .setEnvironment(Constants.PAYMENTS_ENVIRONMENT)
        .build()

return Wallet.getPaymentsClient(context, walletOptions)
}

Step 7: Check Readiness to Pay with Google Pay

Now that you've described your allowed payment methods, you need to check readiness to pay with the Google Pay API. To check readiness to pay with Google Pay's API:

Add allowedPaymentMethods to the baseRequest object.
Call isReadyToPay() to determine if the user can make payments with the Google Pay API.

fun isReadyToPayRequest(): JSONObject? =
    try {
        baseRequest
            .put("allowedPaymentMethods", JSONArray().put(baseCardPaymentMethod()))
    } catch (e: JSONException) {
        null
    }

private fun possiblyShowGooglePayButton() {
    val isReadyToPayJson = PaymentsUtil.isReadyToPayRequest() ?: return
    val request = IsReadyToPayRequest.fromJson(isReadyToPayJson.toString()) ?: return
    // The call to isReadyToPay is asynchronous and returns a Task. We need to provide an
    // OnCompleteListener to be triggered when the result of the call is known.
    val task = paymentsClient.isReadyToPay(request)
    task.addOnCompleteListener { completedTask ->
        try {
            completedTask.getResult(ApiException::class.java)?.let(::setGooglePayAvailable)
        } catch (exception: ApiException) {
            // Process error
            Log.w("isReadyToPay failed", exception)
        }
    }
}

Step 8: Add Google Pay Button

Now that you've checked readiness to pay with Google Pay API, you can add a Google Pay payment button to your website.

For information about the different button types and display requirements, see Google's Brand guidelines.
To try all the different Google Pay buttons, see Google Pay's interactive demo.

PayButton(
    modifier = Modifier
        .testTag("payButton")
        .fillMaxWidth(),
    onClick = onGooglePayButtonClick,
    allowedPaymentMethods = PaymentsUtil.allowedPaymentMethods.toString()
)

Initialize Google Pay Button

override fun onCreate(savedInstanceState: Bundle?) {
  super.onCreate(savedInstanceState)

// Use view binding to access the UI elements
  layout = ActivityCheckoutBinding.inflate(layoutInflater)
  setContentView(layout.root)

// Setup buttons
  googlePayButton = layout.googlePayButton
  googlePayButton.initialize(
      ButtonOptions.newBuilder()
          .setAllowedPaymentMethods(PaymentsUtil.allowedPaymentMethods.toString()).build()
  )
  googlePayButton.setOnClickListener { requestPayment() }

// Check Google Pay availability
  model.canUseGooglePay.observe(this, Observer(::setGooglePayAvailable))
}

Step 9: Create a Payment Data Request

After creating a Google Pay payment button, you need to create a PaymentDataRequest object. The PaymentDataRequest takes in information about the merchant and transaction which is required to start the payment process with Google Pay.

Get Transaction Info

private fun getTransactionInfo(price: String): JSONObject =
    JSONObject()
        .put("totalPrice", price)
        .put("totalPriceStatus", "FINAL")
        .put("countryCode", Constants.COUNTRY_CODE)
        .put("currencyCode", Constants.CURRENCY_CODE)

private val merchantInfo: JSONObject =
    JSONObject().put("merchantName", "Example Merchant")

Request Arguments

Field	Type	Description
`countryCode`	string, required	The ISO country code.
`currencyCode`	string, required	The currency code of the locale.
`totalPrice`	string, required	Total value of the transaction with an optional decimal precision of two decimal places.
`totalPriceStatus`	string, required	The status of the total price used. - Pass FINAL if the total price doesn't change from the amount presented to the buyer. - Pass ESTIMATED if the total price might adjust based on the details of the response, such as sales tax collected that's based on a billing address. - Pass NOT_CURRENTLY_KNOWN when using `totalPriceStatus` for a capability check.

Merchant Info Request Arguments

Field	Type	Description
`merchantID`	string, required	A Google merchant identifier issued after registration with the Google Pay Business Console. Required when PaymentsClient is initialized with an environment property of LIVE
`merchantName`	string, required	Pass in the name of the `Merchant` .

Strong Customer Authentication (SCA) requires the countryCode, totalPrice, and merchantName parameters to meet SCA requirements.

Step 10: Get Buyer Identity

A buyer identity is required before you can proceed with the next steps. You can either create a new buyer identity through the Finix API or use an existing one you’ve already created.

Buyer Identity Data

All buyer Identity fields are optional. However, Finix recommends including basic information (name, email, address, and phone) to make payment operations easier.

Use an existing buyer or create a new buyer.

Buyer Identity Request

curl -i -X POST \
  -u USfdccsr1Z5iVbXDyYt7hjZZ:313636f3-fac2-45a7-bff7-a334b93e7bda \
  https://finix.sandbox-payments-api.com/identities \
  -H 'Content-Type: application/json' \
  -H 'Finix-Version: 2022-02-01' \
  -d '{
    "entity": {
      "phone": "7145677613",
      "first_name": "John",
      "last_name": "Smith",
      "email": "finix_example@finix.com",
      "personal_address": {
        "city": "San Mateo",
        "country": "USA",
        "region": "CA",
        "line2": "Apartment 7",
        "line1": "741 Douglass St",
        "postal_code": "94114"
      }
    },
    "identity_roles": [
      "BUYER"
    ],
    "tags": {
      "key": "value"
    },
    "type": "PERSONAL"
  }'

Buyer Identity Response

{
  "id": "IDmkDvJfxZWMEK56FDFtbozo",
  "created_at": "2024-08-09T09:34:36.87Z",
  "updated_at": "2024-08-09T09:34:36.87Z",
  "application": "APgPDQrLD52TYvqazjHJJchM",
  "entity": {
    "phone": "7145677613",
    "first_name": "John",
    "last_name": "Smith",
    "email": "finix_example@finix.com",
    "personal_address": {
      "line1": "741 Douglass St",
      "line2": "Apartment 7",
      "city": "San Mateo",
      "region": "CA",
      "postal_code": "94114",
      "country": "USA"
    }
  },
  "identity_roles": [],
  "tags": {
    "key": "value"
  },
  "type": "PERSONAL"
}

Step 11: Create a Payment Instrument

Call loadPaymentData using the Google Pay PaymentsClient object, which results in a Task object. Extract the payment token from the PaymentData result object.

Payment Instrument Request

curl -i -X POST \
  -u USfdccsr1Z5iVbXDyYt7hjZZ:313636f3-fac2-45a7-bff7-a334b93e7bda \
  https://finix.sandbox-payments-api.com/payment_instruments \
  -H 'Content-Type: application/json' \
  -H 'Finix-Version: 2022-02-01' \
  -d '{
    "address": {
      "city": "San Francisco",
      "country": "USA",
      "line1": "900 Metro Center Blv",
      "line2": "APT 200",
      "postal_code": "94404",
      "region": "CA"
    },
    "identity": "ID78Fh8mcnnzukVzbdoyex5y",
    "merchant_identity": "IDwhCCvPwCDEmiFd8Be7pDzN",
    "name": "Finix Sandbox",
    "third_party_token": "{\"signature\":\"MEYCIQCYTkaEMgug7pcjzEEdbIn+R57kYO5yYc2KYj41AQQn9wIhAN1QvylvZ2XydVecfejwi2xYS9y3Y9y/MmDnRnUfNw5H\",\"intermediateSigningKey\":{\"signedKey\":\"{\\\"keyValue\\\":\\\"MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE4xc3fjeM9SMTjd1TL2GQCPmgqPf2h42aM3akPh/mTUBqWEgOITruK10A02rQ+4YZOvLCpQKQZzLSAd09nctnuA\\u003d\\u003d\",\\\"keyExpiration\\\":\"1648843199734\"}\\",\"signatures\":[\"MEQCICwCI4s5YCLu4qRCyXwSJ3qG8y3ocFtP1Mque4Uzysl8AiARoD/0qbj5W0Q2PWKpxkEnfcP+nU5kwYS8FyQ9boDTmQ\\u003d\\u003d\"]},\"protocolVersion\":\"ECv2\",\"signedMessage\":\"{\\\"encryptedMessage\\\":\\\"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\\u003d\",\"ephemeralPublicKey\":\"BMqIyb1IyXhuZ4YpWm1PiRr74i3tCwDfQqJ1P4OZ3zK4Rq16SuwgJ605fCEvlViwSQuo2Hpv+CcR+2D3+/YrLB8\\u003d\",\"tag\":\"5K4LlTucDK7jAThbIozYtyoxX95hRNd5cJJGfxWAxw8\\u003d\"}",
    "type": "GOOGLE_PAY"
  }'

Step 12: Create a Payment

Similar to other Finix transactions, after the Payment Instrument is created, you can use the instrument and create a transfer or an authorization to process transactions.

Example Transfer Request

curl https://finix.sandbox-payments-api.com/transfers \
    -H "Content-Type: application/json" \
    -H 'Finix-Version: 2022-02-01' \
    -u  USsRhsHYZGBPnQw8CByJyEQW:8a14c2f9-d94b-4c72-8f5c-a62908e5b30e \
    -d '{
        "merchant": "MUeDVrf2ahuKc9Eg5TeZugvs",
        "currency": "USD",
        "amount": 662154,
        "source": "PIf8dyFFcEGBqPhaG22hPyYs",
    }'

Example Transfer Response

{
  "id": "TR29av3LN1TAGPbXscsup1tt",
  "amount": 662154,
  "state": "SUCCEEDED",
  "currency": "USD",
  "created_at": "2022-08-25T20:39:37.59Z",
  "updated_at": "2022-08-25T20:39:38.17Z"
}