Deep Linking Done Right: Integrate Apple & Google Pay with Nexi in One Flow

Aug 04, 2025 |

12 minutes read

Seamless Apple & Google Pay Integration with Nexi via Deep Linking

To streamline the payment process and improve user experience, Apple and Google Pay have been integrated into the Flutter application using Nexi’s payment gateway with deep linking. This empowers users to complete secure, real-time transactions seamlessly, whether the app is running in the foreground or background, ensuring smooth and reliable payment workflows, a hallmark of effective Flutter app development.

Leveraging Nexi and Flutter’s capabilities, the following key functionalities are integrated based on project requirements:

Platform-Specific Payment Handling: Use Nexi’s SDKs and Flutter plugins to ensure Apple Pay and Google Pay transactions work seamlessly on both Android and iOS, including support for deep linking to handle return flows after payment.
Real-Time Transaction Confirmation: Leverage Nexi’s APIs to instantly confirm payment status, ensuring users receive up-to-date transaction feedback.
Event-Based Payment Triggers: Payments can be triggered on specific user actions, such as checkout or in-app purchases, to deliver a streamlined and responsive experience.
Actionable Responses: Allow users to complete purchases, verify transactions, or view receipts directly from their mobile devices with minimal friction.
Background & Foreground Payment Handling: Transactions are properly handled in all app states, maintaining a seamless experience whether the app is active or in the background.
Secure Data Handling: Ensure sensitive payment data is securely transmitted and stored, following PCI-DSS and best security practices.

These integrations provide a secure, seamless, and responsive payment experience, delivering real-time confirmations and enhancing user trust.

Problem Learning

The client project required a robust, user-friendly payment solution to support secure in-app purchases and checkout flows. Key technical implementations included:

Cross-Platform Payment Integration

Integrated Nexi to enable Apple Pay on iOS and Google Pay on Android devices.
Ensured seamless payment handling in both foreground and background states.
Configured merchant IDs, payment profiles, and environment-specific endpoints for consistent behavior.

Foreground & Background Payment Handling

Implemented deep linking to handle payment return flows, whether the app is in the foreground, background, or terminated.
Ensured secure verification of transaction results when the user returns from the payment provider.
Implemented receipt generation and transaction logs to keep records up to date.

Event-Triggered Payments

Triggered payment flows based on checkout or in-app purchase events.
Enabled real-time transaction updates so users are aware of payment status instantly.
Delivered confirmations through in-app messages or emails to maintain transparency.

These integrations ensured a smooth payment experience with minimal friction while maintaining secure, reliable processing.

Overcoming Challenges

1. Cross-Platform Payment Delivery

Integrated Nexi payment gateway with support for both Apple Pay and Google Pay.
Addressed platform-specific requirements, such as iOS entitlements and Android Pay configurations.
Ensured consistent user experience across all devices.

2. Handling Background Transactions

Configured deep linking to handle the return flow from the payment app to the Flutter app.
Verified transaction details securely in the background and updated app state accordingly.
Managed potential transaction cancellations or interruptions gracefully.

3. Dynamic and Personalized Payment Experience

Enabled storing user preferences (e.g., saved cards, preferred payment method) for faster future checkouts.
Used Nexi’s tokenization features to avoid re-entering card details and improve security.
Personalized payment confirmation messages based on user profile and purchase details.

4. Accessing Payment History & Records

Implemented Nexi’s transaction query APIs to retrieve past payment records.
Enabled users to review their previous transactions through a secure history screen.
Designed efficient data caching to minimize repeated server calls while ensuring up-to-date data.

How the Problem Was Solved

1. Efficient Payment Integration

Integrated Nexi SDK with Apple Pay and Google Pay to support in-app payments.
Set up merchant profiles, certificates, and environment configurations for each platform.
Enabled deep linking return flows to handle post-payment redirection seamlessly.

2. Background Payment Handling

Implemented transaction confirmation on background or terminated states using deep linking callbacks.
Verified payments securely through Nexi’s APIs before updating the app state.
Ensured a consistent user experience even when the app is reopened after a transaction.

3. Personalized Checkout & Confirmation

Added deep links within payment confirmations to navigate users to the order summary or receipt pages.
Dynamically generated confirmation messages based on purchase type.
Displayed a paginated transaction history to help users easily browse their payments.

4. Robust Error & Retry Handling

Implemented a robust retry mechanism for failed or interrupted payments, allowing users to safely attempt a transaction again without data loss.
Used clear, user-friendly error messaging and status indicators to keep users informed about any payment issues and guide them through recovery steps.

5. Security & Compliance

Ensured all payment data is handled according to PCI-DSS standards for secure payment processing.
Integrated tokenization and encryption methods to protect sensitive user data both in transit and at rest, meeting strict compliance requirements from Apple Pay, Google Pay, and Nexi.

A) Configured iOS permissions for Apple Pay and Google Pay

<key>NSAppleMusicUsageDescription</key>
<string>We use Apple Pay to process your payments securely.</string>
<key>com.apple.developer.in-app-payments</key>
<array>
<string>merchant.com.yourcompany.app</string>
</array>

B) Configured Android permissions for Apple Pay and Google Pay:

<uses-permission android:name=”android.permission.INTERNET”/>
<uses-permission android:name=”android.permission.ACCESS_NETWORK_STATE”/>

C) configured merchant profiles



final nexi = NexiSdk();
await nexi.initialize(
  merchantId: "your_merchant_id",
  environment: NexiEnvironment.production,
);

D). Retrieved and handled secure tokens for transaction processing



Future getTransactionToken() async {
  final tokenResponse = await nexi.requestPaymentToken(
    amount: 19.99,
    currency: "EUR",
    paymentMethod: PaymentMethod.applePay,
  );
  if (tokenResponse.isSuccess) {
    print("Received secure token: ${tokenResponse.token}");
    // Proceed to confirmation
  } else {
    print("Token error: ${tokenResponse.errorMessage}");
  }
}

Payment Flow Summary

A). Configured iOS permissions for Apple Pay and Google Pay.
B). Configured Android permissions for Apple Pay and Google Pay.
C). Initialized Nexi SDK and configured merchant profiles.
D). Retrieved and handled secure tokens for transaction processing.

Scalability and Performance Best Practices

1. Efficient Data Sync & API Rate Optimization

Batched transaction data uploads to minimize network load.
Used secure caching to avoid redundant calls to Nexi’s servers.

2. Optimized Payment Data Retrieval & Storage

Leveraged local secure storage for tokens to prevent unnecessary re-fetching.
Applied real-time payment status streaming for a faster confirmation UI.

3. Personalized Checkout & Progress Tracking

Integrated user-preference saving for repeat purchases.
Designed animated payment progress indicators to build user trust.
Triggered personalized payment reminders for abandoned carts or saved checkouts.

These optimizations ensure a smooth, secure, and high-performance payment experience while maintaining a scalable, real-time transaction processing environment.

Enable Seamless Apple & Google Pay with Nexi

The Way Forward

By integrating Apple Pay and Google Pay through Nexi’s payment gateway, developers can deliver a fast, secure, and seamless payment experience across both iOS and Android platforms. Leveraging deep linking ensures reliable handling of foreground and background transactions, real-time confirmations, and personalized user interactions, all crucial components for modern in-app payment systems.

This implementation not only enhances user satisfaction but also demonstrates the importance of choosing the right Flutter development company to handle complex, cross-platform payment solutions. With the right expertise, businesses can ensure scalable, compliant, and high-performance payment workflows tailored to evolving customer expectations.