Mpesa plugin

Use this plugin to implement Lipa Na MPESA Online.

Getting Started


  1. Create an account on the Safaricom Developer Portal
  2. Create a Lipa na MPESA Online App
  3. Get your keys -> ConsumerKey and ConsumerSecret


This plugin requires good understanding of the MPESA C2B concept, in as much as it will help you complete the process, you will also need to get things right in order to have it serve you right. With that said,

These two places will help you get started on a better gear.

  1. Safaricom API Tutorial
  2. Safaricom Developer Portal Docs

From here, it's now simpler to have it on your app.

  1. You will need to set the keys before initiating the payment.
    import 'package:mpesa_flutter_plugin/mpesa_flutter_plugin.dart';
    void main(){
    runApp(new MyApp());
  1. Initiate the payment.

dynamic transactionInitialisation;
//Wrap it with a try-catch
try {
//Run it
transactionInitialisation =
        await MpesaFlutterPlugin.initializeMpesaSTKPush(
                businessShortCode: <your_code>,//use your store number if the transaction type is CustomerBuyGoodsOnline
                transactionType: TransactionType.CustomerPayBillOnline, //or CustomerBuyGoodsOnline for till numbers
                amount: <amount_in_string_format>,
                partyA: <users_phone_to_request_payment>,
                partyB: <your_code>,
                callBackURL: <uri_to_receive_payment_results>,
                accountReference: <could_be_order_number>,
                phoneNumber: <users_phone_to-request_payment>,
                baseUri: <live_or_sandbox_base_uri>,
                transactionDesc: <short_description>,
                passKey: <your_passkey>);
} catch (e) {
//you can implement your exception handling here.
//Network un-reachability is a sure exception.

  Other 'throws':
  1. Amount being less than 1.0
  2. Consumer Secret/Key not set
  3. Phone number is less than 9 characters
  4. Phone number not in international format(should start with 254 for KE)


With that you are pretty much done. Here is a breakdown of the params required :

  1. businessShortCode & partyB which you can apply from the developer portal mentioned in credentials, alternatively, use 174379 for test purposes.
  2. amount amount you expect from customer, in Ksh, double.
  3. phoneNumber & partyA the user's phone number to request payment from.
  4. callBackURL is where the payment results will be POSTed to you, Uri, if it has a path then specify host & path.
  5. accountReference what are the payments for? a short ref like users' order, account number...will be displayed to the user when requesting completion of payment.
  6. transactionDesc brief description of the transaction. Not actually a description, a descriptive word. (Sometimes optional)
  7. passKey obtained from portal, will be blended with a few more things to generate your final password later, alternatively, use bfb279f9aa9bdbcf158e97dd71a467cd2e0c893059b10f78e6b72ada1ed2c919 for test purposes.
  8. baseUri is the url that your transaction should be processed in. Now required as Uri for uniformity purposes, Note: Remember to switch to live instance URL before moving to prod.( is for testing)

Docs at a glance.

When you place the request, and network does it's job well, the MPESA payment processor will validate your parameters and send your an acknowledgement or an error response immediately: case success: expect something of this sort in transactionInitialisation var.

    "MerchantRequestID": "1466 - 405147 - 1",
    "CheckoutRequestID" : "ws_CO_DMZ_370754209_06062019172849964",
    "ResponseCode" : "0",
    "ResponseDescription": "Success.Request accepted for processing",
    "CustomerMessage" : "Success.Request accepted for processing"

It means just that, accepted for processing, yet to be processed.

else, if some of your params are not accepted, expect something of this sort:

    "requestId": "751-526141-1",
    "errorCode": "400.002.02",
    "errorMessage": "Bad Request - Invalid Amount"

After this, the payment processor will proceed to seek the user and hopefully find, hopefully accepts the payment by giving correct pin, and hopefully they have enough amount ... case success, expect something like this on your backend, where the callBackURL points to:

{ "Body":
    { "stkCallback":
            { "MerchantRequestID": "1466-405147-1",
            "CheckoutRequestID": "ws_CO_DMZ_370754209_06062019172849964",
            "ResultCode": 0,
            "ResultDesc": "The service request is processed successfully.",
            "CallbackMetadata": {
                                        "Name": "Amount",
                                        "Value": 100.00
                                        "Name": "MpesaReceiptNumber",
                                        "Value": "NF68F38A1G"
                                        "Name": "Balance"
                                        "Name": "TransactionDate",
                                        "Value": 20190606172857




case failure of a transaction, this is a sample of your result:

                "ResultDesc":"[MpesaCB - ]The initiator information is invalid."




That's what in the docs in summary.

Plugin In Action


Pull Requests are welcomed to this plugin project on GitHub.