Google Wallet loyalty card integration in mobile app

Google Wallet Integration for Loyalty Cards in Mobile Apps

Google Wallet API works differently from PassKit. There's no file archive — a card is created via REST API, and a JWT token containing the object is sent to the device. For loyalty cards, use the LoyaltyClass + LoyaltyObject. Skipping the LoyaltyClass creation is impossible: Google will reject an object without a class.

Setup: Google Pay & Wallet Console

Before coding, three steps in console.wallet.google.com:

1. Create an issuer account (Issuer Account)
2. Create a LoyaltyClass — a card template with logo, colors, fields
3. Get service account credentials for server calls

issuerId is a numeric issuer identifier, e.g., 3388000000022142. classId is formed as {issuerId}.{classPostfix}, e.g., 3388000000022142.loyalty_2024.

Creating LoyaltyClass via API

from google.oauth2 import service_account
from googleapiclient.discovery import build

credentials = service_account.Credentials.from_service_account_file(
    'service_account.json',
    scopes=['https://www.googleapis.com/auth/wallet_object.issuer']
)
service = build('walletobjects', 'v1', credentials=credentials)

loyalty_class = {
    "id": "3388000000022142.loyalty_2024",
    "issuerName": "YourShop",
    "reviewStatus": "UNDER_REVIEW",
    "programName": "YourShop Loyalty Program",
    "programLogo": {
        "sourceUri": { "uri": "https://yourshop.com/logo.png" },
        "contentDescription": { "defaultValue": { "language": "en", "value": "YourShop Logo" } }
    },
    "hexBackgroundColor": "#1E5AC8",
    "countryCode": "US",
    "localizedIssuerName": {
        "defaultValue": { "language": "en", "value": "YourShop" }
    }
}

service.loyaltyclass().insert(body=loyalty_class).execute()

reviewStatus: "UNDER_REVIEW" is the required initial state. Google manually reviews the class (usually 1–3 days). Until approved, cards can only be added in test mode.

Creating LoyaltyObject and JWT

Each user gets a separate LoyaltyObject:

import jwt
import time

loyalty_object = {
    "id": f"3388000000022142.user_{user_id}",
    "classId": "3388000000022142.loyalty_2024",
    "state": "ACTIVE",
    "loyaltyPoints": {
        "label": "Points",
        "balance": { "int": user_points }
    },
    "barcode": {
        "type": "QR_CODE",
        "value": f"USER-{user_id}",
        "alternateText": f"USER-{user_id}"
    },
    "textModulesData": [
        {
            "header": "Level",
            "body": user_tier,
            "id": "tier"
        }
    ]
}

# Create the object via API
service.loyaltyobject().insert(body=loyalty_object).execute()

# Generate JWT for client
payload = {
    "iss": service_account_email,
    "aud": "google",
    "typ": "savetowallet",
    "iat": int(time.time()),
    "payload": {
        "loyaltyObjects": [{ "id": loyalty_object["id"] }]
    }
}

token = jwt.encode(payload, private_key, algorithm="RS256")

JWT is sent to the mobile app. JWT lifespan is maximum 1 hour.

Android: Adding Card via Google Wallet API

import com.google.android.gms.pay.Pay
import com.google.android.gms.pay.PayApiAvailabilityStatus
import com.google.android.gms.pay.PayClient

private lateinit var walletClient: PayClient

override fun onCreate(savedInstanceState: Bundle?) {
    walletClient = Pay.getClient(this)
    checkWalletAvailability()
}

private fun checkWalletAvailability() {
    walletClient
        .getPayApiAvailabilityStatus(PayClient.RequestType.SAVE_PASSES)
        .addOnSuccessListener { status ->
            if (status == PayApiAvailabilityStatus.AVAILABLE) {
                showAddToWalletButton()
            }
        }
}

private fun saveToWallet(jwt: String) {
    walletClient.savePasses(jwt, this, ADD_TO_GOOGLE_WALLET_REQUEST_CODE)
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    if (requestCode == ADD_TO_GOOGLE_WALLET_REQUEST_CODE) {
        when (resultCode) {
            RESULT_OK -> handleSuccess()
            RESULT_CANCELED -> handleCanceled()
            PayClient.SavePassesResult.SAVE_ERROR ->
                data?.let { handleError(it.getStringExtra(PayClient.EXTRA_API_ERROR_MESSAGE)) }
        }
    }
}

PayClient.RequestType.SAVE_PASSES checks that Google Wallet is installed and functional. On devices without GMS (Huawei), Google Wallet is unavailable.

Updating Card Data

Change the points balance — PATCH request to the existing object:

patch_body = {
    "loyaltyPoints": {
        "balance": { "int": new_points_value }
    }
}
service.loyaltyobject().patch(
    resourceId=f"3388000000022142.user_{user_id}",
    body=patch_body
).execute()

Google Wallet automatically syncs changes on the device within minutes. No push notifications required.

Timeline

2–3 days: creating LoyaltyClass, server-side object generation and JWT, integrating PayClient into Android app. Plus 1–3 days for Google's class review. Pricing is calculated individually.