eps_payment_gateway 1.0.0

Flutter package for EPS (Easy Payment System) payment gateway integration. Supports sandbox and live environments with full-screen and modal bottom sheet payment flows. Handles authentication, HMAC-SH [...]

eps_payment_gateway

A Flutter package for integrating the EPS (Easy Payment System) payment gateway into your Flutter application. Supports sandbox and live environments, handles HMAC-SHA512 request signing, JWT authentication, and transaction verification automatically.

Supported payment methods: Visa · Mastercard · American Express · bKash · Nagad · Rocket · and more.

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Features

• One-call payment flow — EpsPaymentGateway.pay()
• Full-screen page or modal bottom sheet display modes
• Automatic HMAC-SHA512 x-hash signing on every request
• Automatic JWT token acquisition
• Post-payment transaction verification
• Sandbox and live environment toggle
• Auto-detects platform (Android / iOS / Web) for the correct transactionTypeId
• Typed result: success, failed, cancelled, error — never throws

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Installation

dependencies:
  eps_payment_gateway: ^1.0.0

Android

Add internet permission to android/app/src/main/AndroidManifest.xml:

<uses-permission android:name="android.permission.INTERNET" />

iOS

Add the following to ios/Runner/Info.plist:

<key>NSAppTransportSecurity</key>
<dict>
  <key>NSAllowsArbitraryLoads</key>
  <true/>
</dict>

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Quick Start

import 'package:eps_payment_gateway/eps_payment_gateway.dart';

// 1. Create the gateway once (e.g. in a service or provider).
final eps = EpsPaymentGateway(
  config: EpsConfig(
    merchantId: 'your-merchant-id',
    storeId:    'your-store-id',
    hashKey:    'your-hash-key',
    userName:   '[e-mail]',
    password:   'yourPassword',
    environment: EpsEnvironment.sandbox, // switch to .live for production
  ),
);

// 2. Call pay() from a widget.
Future<void> checkout(BuildContext context) async {
  final result = await eps.pay(
    context: context,
    order: EpsOrder(
      orderId:         'ORDER-001',
      amount:          150.00,
      customerName:    'Rahim Uddin',
      customerEmail:   '[e-mail]',
      customerPhone:   '01712345678',
      customerAddress: 'Uttara, Dhaka',
      customerCity:    'Dhaka',
      customerPostcode:'1230',
      products: [
        EpsProduct(name: 'T-Shirt', quantity: 2, price: 75.00),
      ],
    ),
    mode: EpsDisplayMode.modalBottomSheet, // or .fullScreen
  );

  // 3. Handle the result.
  switch (result.status) {
    case EpsPaymentStatus.success:
      print('Paid! EPS TXN: ${result.epsTransactionId}');
    case EpsPaymentStatus.failed:
      print('Payment failed: ${result.errorMessage}');
    case EpsPaymentStatus.cancelled:
      print('User cancelled.');
    case EpsPaymentStatus.error:
      print('Error: ${result.errorMessage}');
  }
}

---

Display Modes

Mode	Description
EpsDisplayMode.fullScreen	Pushes a full-screen Scaffold with an app bar
EpsDisplayMode.modalBottomSheet	Slides up a bottom sheet at 92 % of screen height

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API Reference

EpsConfig

Property	Type	Required	Description
merchantId	String	✅	Your EPS merchant UUID
storeId	String	✅	Your EPS store UUID
hashKey	String	✅	Secret key for HMAC-SHA512 signing
userName	String	✅	EPS merchant login email
password	String	✅	EPS merchant login password
environment	EpsEnvironment		.live (default) or .sandbox

EpsOrder

Property	Type	Required	Description
orderId	String	✅	Your unique order ID
amount	double	✅	Payment amount
customerName	String	✅
customerEmail	String	✅
customerPhone	String	✅
customerAddress	String	✅
customerCity	String	✅
customerPostcode	String	✅
products	List<EpsProduct>		Product line items
merchantTransactionId	String?		Auto-generated if omitted (≥ 10 digits)
transactionTypeId	int?		1=Web, 2=Android, 3=iOS. Auto-detected if omitted

EpsPaymentResult

Property	Type	Description
status	EpsPaymentStatus	success, failed, cancelled, error
isSuccess	bool	Convenience getter
merchantTransactionId	String?	Your transaction ID
epsTransactionId	String?	EPS-assigned transaction ID
errorMessage	String?	Error description if applicable
details	EpsTransactionStatus?	Full verification response

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Environments

Environment	API Base URL
EpsEnvironment.sandbox	https://sandboxpgapi.eps.com.bd
EpsEnvironment.live	https://pgapi.eps.com.bd

Sandbox credentials are available from the EPS merchant portal.

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How It Works

Your App
  │
  ├─ 1. EpsPaymentGateway.pay()
  │       POST /v1/Auth/GetToken          → JWT token
  │       POST /v1/EPSEngine/InitializeEPS → RedirectURL
  │
  ├─ 2. Opens RedirectURL in WebView
  │       User selects payment method and completes payment
  │
  ├─ 3. EPS redirects to internal callback URL
  │       WebView intercepts it (page never loads)
  │
  └─ 4. GET /v1/EPSEngine/CheckMerchantTransactionStatus
          Returns EpsPaymentResult to your code

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License

MIT © Pritom Chaki