flutter_wallet_kit

One API for adding Apple Wallet .pkpass files and Google Wallet metadata or signed JWTs.

Features

Presents Apple's native PKAddPassesViewController.
Calls Google Wallet's PayClient.savePasses or savePassesJwt flow.
Checks device/API availability.
Detects an installed Apple pass through PKPassLibrary.containsPass.
Returns strongly typed results instead of leaking platform exceptions.
Includes Apple's native PKAddPassButton and Google's official localized Android XML assets.

Install

dependencies:
  flutter_wallet_kit: ^0.0.1

Supported targets: iOS 15+ and Android API 24+.

Use

import 'dart:typed_data';

import 'package:flutter_wallet_kit/flutter_wallet_kit.dart';

const wallet = FlutterWalletKit();

final supported = await wallet.isWalletSupported();
if (!supported) return;

final result = await wallet.addPass(
  iosPassData: myPkpassBytes,
  androidJwt: mySignedGoogleWalletJwt,
);

if (result == WalletResult.success) {
  print('Pass added!');
}

Both arguments may be supplied from shared code. Native code uses only its platform's value.

Build Google Wallet metadata

GoogleWalletPass.metadata supports generic, loyalty, offer, giftCard, eventTicket, flight, and transit. It generates standard envelope fields and qualified object/class IDs. Add only pass-specific fields through values.

final passId = DateTime.now().microsecondsSinceEpoch.toString();

final pass = GoogleWalletPass.metadata(
  type: GoogleWalletPassType.generic,
  issuerEmail: 'google-wallet-backend@example.iam.gserviceaccount.com',
  issuerId: AppConstants.issuerId,
  objectId: passId,
  classId: 'car_card',
  values: {
    'hexBackgroundColor': '#4285f4',
    'cardTitle': {
      'defaultValue': {
        'language': 'en',
        'value': 'My personal card [DEMO ONLY]',
      },
    },
    'subheader': {
      'defaultValue': {
        'language': 'en',
        'value': 'You are just better',
      },
    },
    'header': {
      'defaultValue': {
        'language': 'en',
        'value': 'OOOOOOO Satalana',
      },
    },
    'barcode': {'type': 'QR_CODE', 'value': passId},
    'textModulesData': [
      {'header': 'POINTS', 'body': '67 69', 'id': 'points'},
    ],
  },
);

Android SDK signs this metadata using your registered app-signing certificate. No service-account private key is stored in Flutter.

Check Apple pass status

final status = await wallet.getPassStatus(iosPassData: myPkpassBytes);
final isAdded = status == WalletPassStatus.added;

Google Wallet has no equivalent client API, so Android returns WalletPassStatus.unsupported.

Official buttons

AddToAppleWalletButton(
  onPressed: () => wallet.addPass(iosPassData: myPkpassBytes),
)

AddToGoogleWalletButton(
  pass: pass,
  onSuccess: () => showSnackBar(context, 'Success!'),
  onCanceled: () => showSnackBar(context, 'Action canceled.'),
  onError: (error) => showSnackBar(context, error.toString()),
)

For complete control, pass developer-authored JSON directly:

AddToGoogleWalletButton(
  pass: myCompleteJsonString,
  onSuccess: onSuccess,
  onCanceled: onCanceled,
  onError: onError,
)

Or validate/store it first with GoogleWalletPass.custom(myCompleteJsonString). Existing manual button usage remains supported through onPressed.

Each button renders only on its native platform. Apple uses system-provided, localized PKAddPassButton. Android bundles Google's official localized XML assets, enforces its 200dp × 48dp minimum, and includes required 8dp clear space by default.

Backend requirement

For signed JWT mode, generate and sign Google Wallet JWTs on a trusted backend. Never ship a service-account private key in a Flutter app. For metadata mode, Android's SDK signs the JSON using the app certificate. Register the Android package name and signing-certificate SHA-1 fingerprint in Google Wallet Business Console.

Apple .pkpass files must include a valid Apple-issued signature. Pass bytes may be downloaded by the app, but pass signing belongs on a secure server.

Results

addPass returns one of:

success
cancelled
alreadyAdded (iOS)
unsupportedPlatform
walletUnavailable
invalidPass
operationInProgress
internalError

Platform notes

No Wallet entitlement is needed merely to present and add a signed .pkpass. Access to other passes remains governed by Apple's PassKit entitlements.

Android SDK dependency: com.google.android.gms:play-services-pay:16.5.0.