Flutter SDK

The Flutter SDK embeds Payment Platform checkout into a Flutter app via a WebView. It supports the Checkout protocol only and handles the full payment flow including 3DS app-to-app authentication and deep link callbacks.

The SDK is maintained at openpaymentplatform-net/flutter_openpaymentplatform.

Installation

Add the package to your pubspec.yaml:

dependencies:
  openpaymentplatform_flutter: ^1.0.4

Then run:

flutter pub get

Initialize the SDK

Call initialize once at app startup before making any payment requests:

OpenPaymentPlatform().initialize(
  backendUrl: 'https://your-checkout-url.example.com',
  merchantKey: 'your-merchant-key',
  password: 'your-api-password',
);

Parameter	Description
backendUrl	Your CHECKOUT_URL provided by your account manager
merchantKey	Admin panel → Merchants → your merchant → Test key
password	Admin panel → Merchants → your merchant → Password. Used for hash computation only — never sent in requests.

Create a payment request

Build an OpenPaymentPlatformRequest with your order details and callback URLs:

final request = OpenPaymentPlatformRequest(
  operation: OpenPaymentPlatformOperation.purchase,
  successUrl: 'https://your-app.example/payment/success',
  cancelUrl: 'https://your-app.example/payment/cancel',
  errorUrl: 'https://your-app.example/payment/error',
  order: OpenPaymentPlatformOrder(
    number: 'ORDER-123',
    amount: '10.00',
    currency: 'USD',
  ),
);

Available operations

Method	Description
OpenPaymentPlatform().checkStatus(paymentId)	Retrieve the current status of a payment
OpenPaymentPlatform().refundPayment(paymentId, amount)	Issue a full or partial refund
OpenPaymentPlatform().voidPayment(paymentId)	Void an authorized payment before capture

3DS handling

The SDK manages 3DS app-to-app authentication automatically. Configure your app to handle deep links for the redirect back from the card issuer. See your framework's deep link documentation for setup details.

Related

• Resources and configuration — full parameter reference for the session creation request
• Callbacks — server-to-server payment result notifications
• Redirects and returns — how success_url and cancel_url work