Google Pay via Direct API

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Google Pay with DEUNA
1. Get the payment methods
2. Initialize the Google Pay Web SDK
3. Purchase with Google Pay

This guide covers how to integrate Google Pay directly with DEUNA's API. Direct integration gives you full control over the payment flow, making it ideal for merchants who need custom implementations or have existing payment systems. This integration supports one-time payments.

Google Pay with DEUNA#

The following is the standard process for a Google Pay purchase with DEUNA:

Get the payment methods
Initialize the Google Pay Web SDK
Purchase with Google Pay

1. Get the payment methods#

Retrieve the Google Pay credential ID and SDK configuration parameters.

→ See Get Payment Methods API reference

Response

JSON

{
  "data": [
    {
      "allow_installments_plan": true,
      "credentials": {
        "external_merchant_id": "DEUNA_GOOGLE_MERCHANT_ID"
      },
      "enabled": true,
      "extra_params": {
        "allowed_auth_methods": [
          "PAN_ONLY",
          "CRYPTOGRAM_3DS"
        ],
        "allowed_card_networks": [
          "VISA",
          "MASTERCARD",
          "AMEX"
        ],
        "merchant_name": "Test DEUNA"
      },
      "id": "ef2319fe-f88d-4d8d-b4d1-e4fa08f18651",
      "method_type": "wallet",
      "payment_provider": "google_pay",
      "processor_name": "google_pay"
    }
  ]
}

2. Initialize the Google Pay Web SDK#

Refer to the following Google Pay documentation for the full reference:

Import the Google Pay JS SDK

Add the following script to your page:

HTML

<script src="https://pay.google.com/gp/p/js/pay.js"></script>

Complete integration example

JavaScript

// 1. Check availability
const paymentsClient = new google.payments.api.PaymentsClient({
  environment: 'PRODUCTION' // or 'TEST' for sandbox
});

const isReadyToPayRequest = {
  apiVersion: 2,
  apiVersionMinor: 0,
  allowedPaymentMethods: [
    {
      type: 'CARD',
      parameters: {
        allowedAuthMethods: ['PAN_ONLY', 'CRYPTOGRAM_3DS'], // from extra_params.allowed_auth_methods
        allowedCardNetworks: ['VISA', 'MASTERCARD', 'AMEX'] // from extra_params.allowed_card_networks
      }
    }
  ]
};

paymentsClient.isReadyToPay(isReadyToPayRequest).then((response) => {
  if (!response.result) {
    // Google Pay not available — hide the button or show a fallback
  }
});

// 2. Build the payment data request (use values from Get Payment Methods endpoint)
const paymentDataRequest = {
  apiVersion: 2,
  apiVersionMinor: 0,
  allowedPaymentMethods: [
    {
      type: 'CARD',
      parameters: {
        allowedAuthMethods: ['PAN_ONLY', 'CRYPTOGRAM_3DS'],
        allowedCardNetworks: ['VISA', 'MASTERCARD', 'AMEX']
      },
      tokenizationSpecification: {
        type: 'PAYMENT_GATEWAY',
        parameters: {
          gateway: 'deuna',
          gatewayMerchantId: '{external_merchant_id}' // from credentials.external_merchant_id
        }
      }
    }
  ],
  merchantInfo: {
    merchantId: '{google-merchant-id}',
    merchantName: 'Test DEUNA' // from extra_params.merchant_name
  },
  transactionInfo: {
    countryCode: 'MX',
    currencyCode: 'MXN',
    totalPrice: '1.00',
    totalPriceStatus: 'FINAL'
  }
};

// 3. Load payment data on button click (must be inside a user gesture)
// The credential-id comes from the `id` field in the Get Payment Methods response
paymentsClient.loadPaymentData(paymentDataRequest).then((paymentData) => {
  // 4. Handle payment authorization
  // Extract the raw token string — send it as-is to DEUNA, without parsing or re-serializing
  const googlePayToken = paymentData.paymentMethodData.tokenizationData.token;

  // Use googlePayToken in step 3 — Create Card or Purchase V2
}).catch((err) => {
  console.error('Google Pay error:', err);
});

3. Purchase with Google Pay#

Once the customer authorizes the payment, loadPaymentData() resolves and delivers an encrypted ECv2 token via paymentData.paymentMethodData.tokenizationData.token. This token must be sent as-is, without any modification, to DEUNA.

You have three options depending on your use case:

3.1 Create Card

Use this option when you want to save the card for future purchases. The token from tokenizationData.token is sent to the Create Card endpoint, which returns a card_id that can be reused in subsequent purchases.

→ See Create Card API reference

JSON

{
  "google_pay": {
    "paymentData": {
      "token": {
        "protocolVersion": "ECv2",
        "signature": "MEQCIH6Q4OwQ0jAceFEkGF0JID6sJNXxOEi4r+mA7biHQS9nwiiNwOrr24RyPeHA0Q==",...
        "intermediateSigningKey": {
          "signedKey": "{\"keyExpiration\":\"1542323393147\",\"keyValue\":\"MFJeFRxyCw==\"}",...
          "signatures": [
            "MEYCIQCO2EIi48s8VTH+ilMEpoXLFfkxAwHjfPSCVED/QDSHmQWpeNmIP+z+tCQHQxP0v"...
          ]
        },
        "signedMessage": "{\"tag\":\"jpGz1F1BVrKbRU9K8+7cZs=\",\"en:\"mKOoXwi8OavZ...\"}"...
      }
    }
  },
  "credential_source": "google_pay"
}

3.2 Purchase with Card ID

Use this option when the card has already been saved via Create Card. This is a standard Purchase V2 request using the card_id returned by the Create Card endpoint — no Google Pay token needed.

→ See Purchase V2 API reference

JSON

{
  "order_token": "{order-token}",
  "order_type": "DEUNA_CHECKOUT",
  "payer_info": {
    "email": "customer@example.com",
    "card_holder_dni": "12345678"
  },
  "payment_source": {
    "method_type": "credit_card",
    "card_info": {
      "card_id": "{deuna-card-id}"
    }
  }
}

3.3 Direct Purchase

Use this option for one-time payments where you don't need to save the card. The token from tokenizationData.token is sent directly in the purchase request.

→ See Purchase V2 API reference

JSON

{
    "order_token": "{{order-token}}",
    "order_type": "DEUNA_CHECKOUT",
    "payer_info": {
        "email": "{{random_user}}@testuser.com",
        "card_holder_dni": "12345678"
    },
    "payment_source": {
        "method_type": "credit_card",
        "card_info": {
            "credential_source": "google_pay",
            "credential_source_config": {
                "type": "google_pay",
                "values": {
                    "system": "DIRECT",
                    "encrypted_data": "{\"signature\":\"MEUCI...Qb27X0\\u003d\",\"intermediateSigningKey\":{\"signedKey\":\"{\\\"keyValue\\\":\\\"MFkwEw...dwluLc74w\\\\u003d\\\\u003d\\\",\\\"keyExpiration\\\":\\\"1732...316\\\"}\",\"signatures\":[\"MEU...z+94I\\u003d\"]},\"protocolVersion\":\"ECv2\",\"signedMessage\":\"{\\\"encryptedMessage\\\":\\\"06PdX...wYvlX4\\\\u003d\\\",\\\"ephemeralPublicKey\\\":\\\"BNPW...4O2S6j0\\\\u003d\\\",\\\"tag\\\":\\\"m3Iv...KY8g\\\\u003d\\\"}\"}"
                }
            }
        }
    },
    "anti_fraud_info": {
        "device": {
            "id": "eyJPUEVOUEFZIjoiIiwiTUVSQ0FET1BBzAzLTk2NjRkYzE3MWQzYiJ9..."
        }
    }
}

Response:

JSON

{
  "order_type": "DEUNA_CHECKOUT",
  "order_token": "4598f493-de86-4fe0-b9fd-c4c6c9847e39",
  "order": {
    "order_id": "DEUNA_CHECKOUT_b6a5c0b6-3df9-4b3b-b778-7086c190062b",
    "currency": "MXN",
    "total_amount": 10000,
    "display_total_amount": "MXN 100,00",
    "status": "succedeed",
    "payment": {
      "data": {
        "status": "processed"
      }
    }
  }
}