am_flutter_paypal

A Flutter plugin for PayPal Advanced Checkout integration (Approval Only). This plugin handles the secure entry and approval of card details using PayPal's native SDKs.

Repository: https://github.com/Abdul520Mannan/am_flutter_paypal

Security Architecture

This plugin follows a secure, backend-driven architecture:

1. No Backend Secrets: Client Secrets and API credentials never exist in the mobile app.
2. Backend Order Creation: Your server creates the PayPal Order using the Orders v2 API.
3. Approval Only: This plugin ONLY handles the approveOrder step.
4. Backend Capture: Your server captures the payment after the plugin returns a success status.

Getting Started

1. Requirements

• Android: minSdk 24+
• iOS: iOS 14.0+

2. Android Setup

In your android/app/src/main/AndroidManifest.xml, add the following intent filter inside the <activity> tag that handles the PayPal return:

<intent-filter android:label="paypalpay">
    <action android:name="android.intent.action.VIEW" />
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="android.intent.category.BROWSABLE" />
    <data android:scheme="com.am.amflutterpaypal" android:host="paypalpay" />
</intent-filter>

3. iOS Setup

In your ios/Runner/Info.plist, add the URL Scheme:

<key>CFBundleURLTypes</key>
<array>
    <dict>
        <key>CFBundleTypeRole</key>
        <string>Editor</string>
        <key>CFBundleURLName</key>
        <string>paypalpay</string>
        <key>CFBundleURLSchemes</key>
        <array>
            <string>com.am.amflutterpaypal</string>
        </array>
    </dict>
</array>

Usage

1. Initialization

Initialize the SDK once with your Client ID and a unique return URL.

final bool initialized = await AmFlutterPaypal.initialize(
  clientId: "YOUR_PAYPAL_CLIENT_ID",
  environment: PayPalEnvironment.sandbox, // or PayPalEnvironment.live
  returnUrl: "com.am.amflutterpaypal://paypalpay",
);

2. Approve Order

Call your backend to get an orderId, then pass it to the plugin along with the PayPalCard details.

final card = PayPalCard(
  cardholderName: "John Doe",
  cardNumber: "1234567812345678",
  expirationMonth: "12",
  expirationYear: "2025",
  securityCode: "123",
  billingAddress: {
    "street": "123 Main St",
    "city": "San Jose",
    "state": "CA",
    "zip": "95131",
    "country": "US",
  },
);

final result = await AmFlutterPaypal.approveOrder(
  orderId: "ORDER_ID_FROM_BACKEND",
  card: card,
);

if (result.success) {
  print("Payment Approved! Order ID: ${result.orderId}");
  // Now call your backend to CAPTURE the payment using result.orderId
} else {
  print("Payment Failed: ${result.errorCode} - ${result.message}");
}

Error Codes

Error Code	Description
SDK_NOT_INITIALIZED	initialize was not called or failed.
PAYMENT_IN_PROGRESS	Another payment approval is already active.
PAYMENT_TIMEOUT	No response from native SDK after 60 seconds.
USER_CANCELLED	User closed the payment/3DS UI.
INVALID_ARGUMENTS	Missing Order ID or card details.
AUTHORIZATION_REQUIRED	Additional authorization (like 3DS) was required but not completed.
PLATFORM_ERROR	An error occurred in the native Android or iOS layer.

Important Security Note

Never include your PayPal Secret Key in your Flutter code. Always use a secure backend to interact with PayPal's REST APIs for order creation and capture.