YooKassa Payment Gateway Integration for Mobile Apps

When integrating payments into a mobile app, the primary challenge is security compliance. Direct handling of bank card data requires PCI DSS Level 1 certification, costing millions of rubles and annual audits. We, a team with 7 years of mobile development experience and over 30 YooKassa projects, solve this via tokenization: the client SDK generates a one-time payment token, and your server processes the payment using this token. No card data leaves the device, eliminating the need for PCI certification.

Problems We Solve

PCI DSS Compliance Overhead

Without tokenization, you must handle sensitive card data and pass a costly PCI DSS Level 1 audit. Our approach through YooKassa tokenization removes this burden entirely. Your infrastructure never touches real card numbers, significantly reducing security risks and compliance costs.

3D Secure Complexity

3D Secure flows often break in mobile apps if not implemented correctly. We handle automatic 3D Secure processing via YooKassa SDK, ensuring smooth redirects and callback handling. In one recent e-commerce project, we reduced payment failure rates from 12% to 2% by optimizing 3D Secure handling.

Supporting Multiple Payment Methods

Users expect flexibility: cards, SberPay, SBP, Apple Pay, Google Pay, and YooMoney. We configure the YooKassa SDK to present the right methods based on your app’s logic, increasing conversion. For a retailer client, adding SBP boosted mobile payments by 30%.

How We Do It: Technical Deep Dive

Tokenization Architecture

YooKassa SDK on the client side (iOS or Android) encrypts card data and sends it directly to YooKassa. The SDK returns a payment token to your app. This token is then passed to your backend, which creates a payment via YooKassa API. Your server never sees real card details.

iOS Integration with YooKassaPayments SDK

We integrate the SDK via CocoaPods or SPM. The payment screen is launched as shown below. We handle token retrieval and error states.

import YooKassaPayments

let inputData = TokenizationModuleInputData(
    clientApplicationKey: "live_your_client_key",
    title: "Your Company",
    subtitle: "Order No. 1234",
    amount: Amount(value: 1500, currency: .rub),
    paymentTypes: [.bankCard, .sberbank, .sbp, .applePay, .yooMoney],
    savePaymentMethod: .on,
    isLoggingEnabled: false
)

let viewController = TokenizationAssembly.makeModule(
    inputData: inputData,
    moduleOutput: self
)
present(viewController, animated: true)

Result handling:

extension PaymentViewController: TokenizationModuleOutput {
    func tokenizationModule(
        _ module: TokenizationModuleInput,
        didTokenize token: Tokens,
        paymentMethodType: PaymentMethodType
    ) {
        dismiss(animated: true)
        sendTokenToBackend(token.paymentToken, paymentMethodType: paymentMethodType.rawValue)
    }

    func didFinish(on module: TokenizationModuleInput, with error: YooKassaPaymentsError?) {
        dismiss(animated: true)
        if let error = error {
            print("YooKassa error: \(error)")
        }
    }
}

Android Integration with YooKassa Payments SDK

We add the dependency (latest version in official documentation):

implementation("ru.yoomoney.sdk.kassa.payments:yookassa-android-sdk:7.x.x")

Payment screen launch:

private val tokenizeLauncher = registerForActivityResult(
    ActivityResultContracts.StartActivityForResult()
) { result ->
    if (result.resultCode == Activity.RESULT_OK) {
        val token = Checkout.createTokenizationResult(result.data!!)
        sendTokenToBackend(
            token.paymentToken,
            token.paymentMethodType.name
        )
    }
}

fun startPayment() {
    val paymentParameters = PaymentParameters(
        amount = Amount(BigDecimal.valueOf(1500), Currency.getInstance("RUB")),
        title = "Your Company",
        subtitle = "Order No. 1234",
        clientApplicationKey = "live_your_client_key",
        shopId = "your_shop_id",
        savePaymentMethod = SavePaymentMethod.ON,
        paymentMethodTypes = setOf(
            PaymentMethodType.BANK_CARD,
            PaymentMethodType.SBERBANK,
            PaymentMethodType.SBP,
            PaymentMethodType.GOOGLE_PAY,
            PaymentMethodType.YOO_MONEY
        )
    )

    val intent = Checkout.createTokenizeIntent(this, paymentParameters)
    tokenizeLauncher.launch(intent)
}

Server-Side Payment Confirmation

Your backend receives the token and creates a payment via YooKassa API:

POST https://api.yookassa.ru/v3/payments
Authorization: Basic base64(shopId:secretKey)
Content-Type: application/json
Idempotence-Key: unique-uuid

{
    "amount": { "value": "1500.00", "currency": "RUB" },
    "capture": true,
    "payment_method_data": {
        "type": "bank_card"
    },
    "confirmation": {
        "type": "mobile_application",
        "return_url": "yourapp://payment/result"
    },
    "payment_token": "token_from_client",
    "description": "Order No. 1234"
}

If the response includes status: pending and confirmation.type: redirect, 3D Secure is required. The SDK handles this automatically; for direct integration, open confirmation_url in SFSafariViewController or Custom Tabs.

Case Study: E-commerce App Performance Boost

On a recent project for a large online store, we integrated YooKassa with tokenization and optimized the payment flow. By fine‑tuning the token request and backend response handling, we reduced average payment processing time from 8 seconds to 1.2 seconds. The mobile checkout abandonment rate dropped by 15%.

Our Integration Process

1. Data Collection – We discuss your payment scenarios, required methods, and app architecture.
2. Audit – Review your current codebase and identify any blocking issues.
3. Design – Plan the tokenization flow, backend endpoints, and error handling.
4. Estimate – Provide a fixed price after analysis (timeline and cost tailored to your project).
5. Development – Integrate YooKassa SDK on iOS/Android, write server-side payment logic, set up webhooks.
6. Testing – Test with YooKassa test environment covering all scenarios.
7. Launch – Assist with App Store and Google Play compliance checks.

Timeline and Cost

Basic integration (one platform, card payments only) takes 2–3 days. Adding extra payment methods or second platform extends time accordingly. Cost is determined after a free audit of your project. Our engineers have 7+ years of mobile experience and have delivered 30+ YooKassa integrations. We guarantee correct 3D Secure handling, refund flows, and adherence to App Store Review Guidelines (sections 4.2 & 5.1).

Common Mistakes to Avoid

• Exposing secret key – never hardcode it in mobile app code.
• Forgetting idempotency key – always send a unique key to avoid duplicate charges.
• Ignoring 3D Secure redirect – test the redirect flow in a controlled environment.
• Not handling network errors – implement retry logic and token regeneration.

What’s Included in Our Work

• Full YooKassa SDK integration (iOS / Android / Flutter)
• Configuration of payment methods per your requirements
• Server‑side endpoint for payment creation and confirmation
• Webhook setup for final status callbacks
• Testing in YooKassa test shop
• Assistance with App Store / Google Play publishing (compliance checks)

To get started, request a free audit from our engineers. We’ll review your app and provide an optimal integration plan with a fixed quote.

Payments in Mobile Apps: In-App Purchase, StoreKit 2, Google Billing, Stripe, RevenueCat

In every monetization project, we balance App Store and Google Play policies, PCI DSS requirements, and purchase verification logic on the backend. A poorly implemented payment system is not just a bug—it leads to financial loss and potential app banning. Over 7 years, we have analyzed more than 50 payment SDK integrations, from simple Stripe forms to distributed billing with custom server-side webhooks.

In-App Purchase: Two Platforms, Two Different APIs

If your app sells digital content or subscriptions, Apple and Google require you to use their payment systems. This is non-negotiable: violating App Store rule 3.1.1 or Google Play Developer Policy results in app removal. Physical goods and offline services are a different story.

StoreKit 2 (iOS 15+)

StoreKit 2 is a complete overhaul of the original StoreKit with async/await API. Product.products(for:), product.purchase(), Transaction.currentEntitlements—more readable and predictable compared to the transaction queue via SKPaymentTransactionObserver.

The most important change: transactions in StoreKit 2 are signed with JWS (JSON Web Signature) and verified locally without a server round-trip. Transaction.verificationResult returns .verified(Transaction) or .unverified(Transaction, VerificationError). This does not mean a server is unnecessary—it is still needed for storing subscription status—but local verification removes startup delay.

StoreKit.AppTransaction verifies the actual app download from the App Store. Required for paid downloads or non-renewing purchases.

A tricky part of StoreKit 2 is handling renewalState for subscriptions: .subscribed, .expired, .inBillingRetryPeriod, .inGracePeriod, .revoked. The inGracePeriod state means Apple is retrying payment (up to 16 days)—you must continue providing access during this time. Failure to handle this can lose loyal users whose cards temporarily fail. Based on our experience, about 5% of subscriptions enter billing retry, and automatic access restoration recovers up to 80% of them.

Google Play Billing Library (v6+)

Google Billing is more complex than StoreKit in terms of scenario handling. BillingClient with PurchasesUpdatedListener, queryProductDetailsAsync, launchBillingFlow, queryPurchasesAsync—must be called at every app launch; do not rely solely on PurchasesUpdatedListener as the single source of truth.

Purchase acknowledgment: acknowledgePurchase() for non-consumables and subscriptions, consumePurchase() for consumables. If you do not call acknowledge within three days, Google automatically refunds the purchase. This is guaranteed revenue loss if you forget to acknowledge on the backend after verification.

ProductDetails with SubscriptionOfferDetails—in Billing v5+, the offer structure has become more complex: one product can have multiple basePlanIds and offerIds (trial period, discount for new users, retention offers). BillingFlowParams.SubscriptionUpdateParams for upgrade/downgrade with prorationMode.

Why Is Server-Side Verification Mandatory?

Never trust only client-side code when unlocking paid content. Client-side verification can be bypassed by modifying the app.

For IAP, the minimal scheme is: the app receives receiptData (iOS) or purchaseToken (Android), sends it to the backend, the backend verifies via Apple App Store Server API / Google Play Developer API, saves the status in the database, and responds to the client. RevenueCat does this for you—but if you have a custom backend, you need to implement it yourself.

Webhooks are more important than they seem. Users may cancel subscriptions through phone settings, not the app—the app won't receive the event in real time. Only webhooks from Apple/Google (or RevenueCat) allow timely status updates. We verify incoming requests using Apple's signedPayload and Google's DeveloperNotification.

How Does RevenueCat Simplify Integration?

Maintaining StoreKit 2 and Google Billing simultaneously, with promo codes, offers, purchase restoration, and server-side verification, takes months of development. RevenueCat handles most of this layer.

RevenueCat is not just a payment SDK. It offers:

• A unified API for iOS and Android (and Stripe for web)
• Server-side verification and subscription status storage
• Webhooks for events (purchase, renewal, cancellation, billing issue)
• Analytics for cohorts, MRR, churn
• A/B testing of offers via Experiments

Purchases.configure(withAPIKey:) at startup, Purchases.shared.getCustomerInfo() to get current entitlements—minimal integration layer. Purchases.shared.purchase(package:) instead of directly calling StoreKit/Billing.

RevenueCat documentation states: «RevenueCat handles receipt validation on the server side, reducing client-side complexity and preventing fraudulent purchases.»

Limitations of RevenueCat: it is paid (free up to $2.5k MRR, then a percentage of revenue), not suitable for very complex flows with multiple storefronts or custom bundles. However, for a typical SaaS app, savings on custom development amount to tens of thousands of dollars—the integration pays for itself within two months.

Stripe in Mobile Apps

Stripe is used for physical goods, services, and B2B payments where IAP is not required by platform policy.

Stripe iOS SDK and Android SDK—PaymentSheet for ready-made payment UI, PaymentSheetFlowController for custom UI with saved cards. Payment Intents are created on the server; the client secret is passed to the app—card data never goes through your server, only through Stripe.

Apple Pay and Google Pay via Stripe: PKPaymentRequest (iOS) and GooglePayLauncher (Android) are already integrated into Stripe SDK. Apple Pay conversion rates are 1.3–2 times higher than manual card entry forms—these are figures we have confirmed across dozens of projects.

Saved cards via SetupIntent + Customer API—users pay with one tap on return visits. Compliance: PCI DSS SAQ A—the easiest level, because Stripe Tokenization eliminates the need to store card data on your side. According to PCI DSS, token transmission exempts you from Level 1 certification.

3DS2 (Strong Customer Authentication) is mandatory for payments in the EU under PSD2. Stripe handles it automatically via PaymentIntent.confirmPayment, but you need to correctly handle the .requiresAction status and return the user to the appropriate screen after authentication.

What Is Included in the Work (Deliverables)

Process and Timeline

We start by clarifying the business model: subscriptions, one-time purchases, consumables, freemium. The architecture depends on this. Testing IAP requires Sandbox accounts (Apple) and License Testers (Google)—this is a separate environment setup.

Apple's Sandbox behaves differently from production: subscriptions renew every 5 minutes instead of monthly, inGracePeriod works differently. It is essential to test scenarios: trial expiration, cancellation, billing retry, refund.

The cost is calculated individually based on the set of tools and complexity of server-side logic. On average, we fit within a budget for a typical integration, but the savings from preventing errors and churn offset this investment within a few months.

Get a consultation for your project—contact us. We will help you choose the optimal payment architecture that passes store reviews and does not break under peak loads.