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3.3.5 - External Payments Program (Japan)

· 3 min read
Hyo
Hyo
Expo IAP Maintainer

Expo IAP 3.3.5 brings Google Play Billing Library 8.3.0 support with the new External Payments program for Japan.

New Features​

External Payments Program (Android 8.3.0+, Japan Only)​

The External Payments program introduces a side-by-side choice between Google Play Billing and the developer's external payment option directly in the purchase flow.

Key Differences from User Choice Billing​

FeatureUser Choice BillingExternal Payments
Billing Library7.0+8.3.0+
AvailabilityEligible regionsJapan only
When presentedAfter initConnection()During requestPurchase()
UISeparate dialogSide-by-side choice in purchase dialog
ListeneruserChoiceBillingListenerAndroiddeveloperProvidedBillingListenerAndroid

New APIs​

developerProvidedBillingListenerAndroid()​

New listener that fires when a user selects the developer's payment option in the External Payments dialog.

import {developerProvidedBillingListenerAndroid} from 'expo-iap';

const subscription = developerProvidedBillingListenerAndroid(async (details) => {
  console.log('User selected developer billing');
  console.log('Token:', details.externalTransactionToken);

  // Process payment with your gateway
  await processPaymentWithYourGateway(details.externalTransactionToken);

  // IMPORTANT: Report to Google within 24 hours
  await reportExternalTransactionToGoogle(details.externalTransactionToken);
});

// Clean up
subscription.remove();

OpenIapEvent.DeveloperProvidedBillingAndroid​

New event type for the External Payments flow.

import {OpenIapEvent} from 'expo-iap';

// Event: 'developer-provided-billing-android'
console.log(OpenIapEvent.DeveloperProvidedBillingAndroid);

BillingProgramAndroid.ExternalPayments​

New billing program type for External Payments.

import {isBillingProgramAvailableAndroid} from 'expo-iap';

// Check if External Payments is available (Japan only)
const result = await isBillingProgramAvailableAndroid('external-payments');
if (result.isAvailable) {
  // External Payments is available for this user
}

New Types​

// Developer billing option for purchase requests
interface DeveloperBillingOptionParamsAndroid {
  billingProgram: BillingProgramAndroid; // should be 'external-payments'
  linkUri: string;
  launchMode: DeveloperBillingLaunchModeAndroid;
}

// Launch mode options
type DeveloperBillingLaunchModeAndroid =
  | 'unspecified'
  | 'launch-in-external-browser-or-app'
  | 'caller-will-launch-link';

// Details received when user selects developer billing
interface DeveloperProvidedBillingDetailsAndroid {
  externalTransactionToken: string;
}

// Updated BillingProgramAndroid
type BillingProgramAndroid =
  | 'unspecified'
  | 'external-content-link'
  | 'external-offer'
  | 'external-payments'; // New in 8.3.0

Complete External Payments Flow Example​

import {useEffect} from 'react';
import {
  initConnection,
  isBillingProgramAvailableAndroid,
  developerProvidedBillingListenerAndroid,
  requestPurchase,
} from 'expo-iap';
import {Platform} from 'react-native';

export default function ExternalPaymentsComponent() {
  useEffect(() => {
    if (Platform.OS !== 'android') return;

    const initialize = async () => {
      // Initialize with External Payments program
      await initConnection({
        enableBillingProgramAndroid: 'external-payments',
      });

      // Check availability (Japan only)
      const result = await isBillingProgramAvailableAndroid('external-payments');
      if (!result.isAvailable) {
        console.log('External Payments not available');
        return;
      }

      // Set up listener for when user selects developer billing
      const subscription = developerProvidedBillingListenerAndroid(
        async (details) => {
          console.log('User selected developer billing');

          // Process payment with your gateway
          await processPayment(details.externalTransactionToken);

          // Report to Google within 24 hours
          await reportToGoogle(details.externalTransactionToken);
        },
      );

      return () => subscription.remove();
    };

    const cleanup = initialize();
    return () => {
      cleanup.then((fn) => fn?.());
    };
  }, []);

  const purchaseWithExternalPayments = async (sku: string) => {
    // Request purchase with developer billing option
    await requestPurchase({
      request: {
        google: {
          skus: [sku],
          developerBillingOption: {
            billingProgram: 'external-payments',
            linkUri: 'https://your-payment-site.com/checkout',
            launchMode: 'launch-in-external-browser-or-app',
          },
        },
      },
      type: 'in-app',
    });
  };

  // Rest of component
}

OpenIAP Updates​

  • openiap-google: 1.3.16 → 1.3.18
  • openiap-gql: 1.3.8 → 1.3.9

Installation​

bun add expo-iap@3.3.5
# or
npm install expo-iap@3.3.5
# or
yarn add expo-iap@3.3.5

References​

Questions or feedback? Reach out via GitHub issues.