A Flutter plugin for making payments via Paystack Payment Gateway. Fully supports Android and iOS.

To use this plugin, add flutter_paystack as a dependency in your pubspec.yaml file.

Then initialize the plugin preferably in the initState of your widget.

import 'package:flutter_paystack/flutter_paystack.dart';

class _PaymentPageState extends State<PaymentPage> {
  var publicKey = '[YOUR_PAYSTACK_PUBLIC_KEY]';
  final plugin = PaystackPlugin();

  @override
  void initState() {
    plugin.initialize(publicKey: publicKey);
  }
}

No other configuration required—the plugin works out of the box.

There are two ways of making payment with the plugin.

1. Checkout: This is the easy way; as the plugin handles all the processes involved in making a payment (except transaction initialization and verification which should be done from your backend).
2. Charge Card: This is a longer approach; you handle all callbacks and UI states.

You initialize a charge object with an amount, email & accessCode or reference. Pass an accessCode only when you have initialized the transaction from your backend. Otherwise, pass a reference.

Charge charge = Charge()
      ..amount = 10000
      ..reference = _getReference()
       // or ..accessCode = _getAccessCodeFrmInitialization()
      ..email = '[email protected]';
    CheckoutResponse response = await plugin.checkout(
      context context,
      method: CheckoutMethod.card, // Defaults to CheckoutMethod.selectable
      charge: charge,
    );

Please, note that an accessCode is required if the method is CheckoutMethod.bank or CheckoutMethod.selectable.

plugin.checkout() returns the state and details of the payment in an instance of CheckoutResponse .

It is recommended that when plugin.checkout() returns, the payment should be verified on your backend.

You can choose to initialize the payment locally or via your backend.

1.a. This starts by making a HTTP POST request to paystack on your backend.

1.b If everything goes well, the initialization request returns a response with an access_code. You can then create a Charge object with the access code and card details. The charge is in turn passed to the plugin.chargeCard() function for payment:

  PaymentCard _getCardFromUI() {
    // Using just the must-required parameters.
    return PaymentCard(
      number: cardNumber,
      cvc: cvv,
      expiryMonth: expiryMonth,
      expiryYear: expiryYear,
    );
  }

  _chargeCard(String accessCode) async {
    var charge = Charge()
      ..accessCode = accessCode
      ..card = _getCardFromUI();

    final response = await plugin.chargeCard(context, charge: charge);
    // Use the response
  }

The transaction is successful if response.status is true. Please, see the documentation of CheckoutResponse for more information.

Just send the payment details to plugin.chargeCard

      // Set transaction params directly in app (note that these params
      // are only used if an access_code is not set. In debug mode,
      // setting them after setting an access code would throw an error
      Charge charge = Charge();
      charge.card = _getCardFromUI();
      charge
        ..amount = 2000
        ..email = '[email protected]'
        ..reference = _getReference()
        ..putCustomField('Charged From', 'Flutter PLUGIN');
      _chargeCard();

You are expected but not required to build the UI for your users to enter their payment details. For easier validation, wrap the TextFormFields inside a Form widget. Please check this article on validating forms on Flutter if this is new to you.

NOTE: You don't have to pass a card object to Charge. The plugin will call-up a UI for the user to input their card.

You can validate the fields with these methods:

This method helps to perform a check if the card number is valid.

Method that checks if the card security code is valid.

Method checks if the expiry date (combination of year and month) is valid.

Method to check if the card is valid. Always do this check, before charging the card.

This method returns an estimate of the string representation of the card type(issuer).

This is quite easy. Just send a HTTP GET request to https://api.paystack.co/transaction/verify/$[TRANSACTION_REFERENCE]. Please, check the official documentaion on verifying transactions.

Paystack provides tons of payment cards for testing.

For help getting started with Flutter, view the online documentation.

An example project has been provided in this plugin. Clone this repo and navigate to the example folder. Open it with a supported IDE or execute flutter run from that folder in terminal.

The project is open to public contribution. Please feel very free to contribute. Experienced an issue or want to report a bug? Please, report it here. Remember to be as descriptive as possible.

Thanks to the authors of Paystack iOS and Android SDKS. I leveraged on their work to bring this plugin to fruition.