This should act as a drop-in solution for CodeIgniter 3 applications that use Mpesa functionality. Currently, only lipa na Mpesa (STK push) has been implemented as it is the most widely used. This is an opensource project though, so feel free to add the rest of the functionality.

config/mpesa.php contains Mpesa configuration you may need. By default, it comes already setup with sandbox credentials, so all you need to change is the CONSUMER_KEY and CONSUMER_SECRET which you can get from Safaricom when you create a new app

libraries/Mpesa_lib.php is the Mpesa API abstraction implementation that contains all the methods you can use

Copy and paste the all directories into your application/ directory

Get your consumer key and secret from Safaricom Daraja

Replace the values in config/mpesa.php to your corresponding credentials

Import the library into your controller

  // Load the mpesa library
  $this->load->library('mpesa_lib');
 
 // $this->mpesa_lib is how you will be accessing the library from now on

Call the lipa_na_mpesa method in your controller

  // $phone - The phone number initiating the transaction - your customer's phone
  // $amount - A non-zero amount (integer)
  $this->mpesa_lib->lipa_na_mpesa($phone, $amount)

This should trigger an STK push request on your customer's device. You can add this to an API request endpoint that accepts a phone number and amount and pass those into the lipa_na_mpesa method

If a transaction succeeds or fails, you'd want to know about it. That's where your callback url comes in. This is where Mpesa will send more information about a transaction to your application.

Ideally, you can create a controller specifically for handling the transaction requests and map your callback url to it. For example: controllers/payments/Handler.php would probably result in your callback url being something on the lines of site.com/payments/handler.

More details on how this works can again be found through Daraja.

The callback urls can be set through config/mpesa.php

Details on what kind of information is returned by the Mpesa API upon completion can be found here.

With that, you should be able to implement both the request and handling of Mpesa requests.