Flutter

Installation

flutter pub add sanwo_flutter sanwo_paystack

Provider packages

Provider	Package
Paystack	sanwo_paystack
Flutterwave	sanwo_flutterwave
Razorpay	sanwo_razorpay
Monnify	sanwo_monnify
Interswitch	sanwo_interswitch

Requirements

• Flutter >= 3.10
• Dart >= 3.0

The SDK uses webview_flutter internally. On Android, no extra setup is needed. On iOS, webview_flutter requires iOS 12+.

Quick start

import 'package:sanwo_flutter/sanwo_flutter.dart';
import 'package:sanwo_paystack/sanwo_paystack.dart';

final sanwo = Sanwo(
  provider: paystackProvider,
  publicKey: 'pk_test_xxxxxxxxxxxx',
);

// In a button handler:
final result = await sanwo(
  context: context,
  options: CheckoutOptions(
    amount: 500000, // 5,000.00 NGN in kobo
    currency: 'NGN',
    customer: CheckoutCustomer(email: 'customer@example.com'),
  ),
);

switch (result.status) {
  case CheckoutStatus.successful:
    print('Paid! Ref: ${result.reference}');
    break;
  case CheckoutStatus.cancelled:
    print('User cancelled');
    break;
  case CheckoutStatus.failed:
    print('Payment failed: ${result.error}');
    break;
}

Sanwo

final sanwo = Sanwo(
  provider: paystackProvider,
  publicKey: 'pk_test_xxxxxxxxxxxx',
  debug: false,   // optional
  timeout: 120,   // optional, seconds
);

Parameter	Type	Required	Default	Description
provider	SanwoProvider	Yes	—	Provider from a provider package
publicKey	String	Yes	—	Your provider public key
debug	bool	No	false	Enable debug logging
timeout	int	No	120	Timeout in seconds

Calling the instance

final result = await sanwo(
  context: context,
  options: CheckoutOptions(...),
);

The context parameter is required — the SDK uses it to present a full-screen webview_flutter page via Navigator.push.

CheckoutOptions

CheckoutOptions(
  amount: 500000,
  currency: 'NGN',
  customer: CheckoutCustomer(email: 'customer@example.com'),
  reference: 'order_abc123',       // optional
  channels: ['card', 'bank'],      // optional
  metadata: {'plan': 'premium'},   // optional
)

CheckoutResult

enum CheckoutStatus { successful, cancelled, failed }

class CheckoutResult {
  final CheckoutStatus status;
  final String? reference;
  final String? error;
  final dynamic providerResponse;
}

Events

Subscribe to lifecycle events:

sanwo.on(SanwoEvent.success, (data) {
  print('Payment succeeded: ${data['reference']}');
});

sanwo.on(SanwoEvent.cancelled, (_) {
  print('User cancelled checkout');
});

Event	Description
SanwoEvent.started	Checkout initiated
SanwoEvent.opened	Checkout UI visible
SanwoEvent.loaded	Provider UI finished loading
SanwoEvent.success	Payment successful
SanwoEvent.cancelled	User dismissed checkout
SanwoEvent.failed	Payment failed
SanwoEvent.closed	Checkout UI dismissed

Removing listeners

// Remove a specific listener
sanwo.off(SanwoEvent.success, myCallback);

// Remove all listeners
sanwo.removeAllListeners();

Full example

import 'package:flutter/material.dart';
import 'package:sanwo_flutter/sanwo_flutter.dart';
import 'package:sanwo_paystack/sanwo_paystack.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: const CheckoutPage(),
    );
  }
}

class CheckoutPage extends StatefulWidget {
  const CheckoutPage({super.key});

  @override
  State<CheckoutPage> createState() => _CheckoutPageState();
}

class _CheckoutPageState extends State<CheckoutPage> {
  final sanwo = Sanwo(
    provider: paystackProvider,
    publicKey: 'pk_test_xxxxxxxxxxxx',
  );

  bool _loading = false;

  Future<void> _pay() async {
    setState(() => _loading = true);

    final result = await sanwo(
      context: context,
      options: CheckoutOptions(
        amount: 500000,
        currency: 'NGN',
        customer: CheckoutCustomer(email: 'customer@example.com'),
        reference: 'order_${DateTime.now().millisecondsSinceEpoch}',
      ),
    );

    setState(() => _loading = false);

    if (!mounted) return;

    switch (result.status) {
      case CheckoutStatus.successful:
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Paid! Ref: ${result.reference}')),
        );
        break;
      case CheckoutStatus.cancelled:
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Payment cancelled')),
        );
        break;
      case CheckoutStatus.failed:
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Failed: ${result.error}')),
        );
        break;
    }
  }

  @override
  void dispose() {
    sanwo.removeAllListeners();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('My Store')),
      body: Center(
        child: ElevatedButton(
          onPressed: _loading ? null : _pay,
          child: Text(_loading ? 'Processing…' : 'Pay ₦5,000'),
        ),
      ),
    );
  }
}

Switching providers

To switch from Paystack to Flutterwave, change the import and provider:

// Before
import 'package:sanwo_paystack/sanwo_paystack.dart';
final sanwo = Sanwo(provider: paystackProvider, publicKey: 'pk_test_xxx');

// After
import 'package:sanwo_flutterwave/sanwo_flutterwave.dart';
final sanwo = Sanwo(provider: flutterwaveProvider, publicKey: 'FLWPUBK_TEST-xxx');

Everything else stays the same.