mpesa stk-push for lipaNaMpesa online sandbox only, expressjs.

mpesa-stk-push-expressjs.js

const express = require('express');
const app = express();
const bodyParser = require('body-parser');
const request = require('request');

app.use(bodyParser.json());

app.listen(3000, () => {
  console.log('Server started on port 3000');
});


let accessToken = '';

const getAccessToken = () => {
    const username = 'your_consumer_key';
    const password = 'your_consumer_secret';
    const url = 'https://sandbox.safaricom.co.ke/oauth/v1/generate?grant_type=client_credentials';

    const auth = 'Basic ' + new Buffer.from(username + ':' + password).toString('base64');

    request(
        {
            method: 'GET',
            url: url,
            headers: {
                Authorization: auth
            }
        },
        (error, response, body) => {
            if (error) {
                console.error(error);
                res.status(500).send('An error occurred while processing the payment.');
            } else {
                console.log(body);
                accessToken = JSON.parse(body).access_token;
                console.log(accessToken);
            }
        }
    );
};

const pay = async () => {
    console.log('accessToken', accessToken);
    const payload = {
        BusinessShortCode: '174379',
        Password:
            'MTc0Mzc5YmZiMjc5ZjlhYTliZGJjZjE1OGU5N2RkNzFhNDY3Y2QyZTBjODkzMDU5YjEwZjc4ZTZiNzJhZGExZWQyYzkxOTIwMTkxMjEzMTA1NzEz',
        Timestamp: '20191213105713',
        TransactionType: 'CustomerPayBillOnline', // or CustomerBuyGoodsOnline
        Amount: '1',
        PartyA: '2547...', // mobile number that will pay
        PartyB: '174379',
        PhoneNumber: '2547...', // mobile number that will pay
        CallBackURL: 'http://arbaaz.herokuapp.com/log.txt', // condider your own firebase functions callBackURL to monitor logs, can still work without it
        AccountReference: 'Clinton',
        TransactionDesc: 'Test'
    };

    request(
        {
            method: 'POST',
            url: 'https://sandbox.safaricom.co.ke/mpesa/stkpush/v1/processrequest',
            headers: {
                Authorization: `Bearer ${accessToken}`,
                'Content-Type': 'application/json'
            },
            body: JSON.stringify(payload)
        },
        (error, response, body) => {
            if (error) {
                console.error(error);
                res.status(500).send('An error occurred while processing the payment.');
            } else {
                console.log(body);
                // res.send(body); res is not defined
            }
        }
    );
};

function initializePayment (){
    getAccessToken();
    setTimeout(pay, 5000);
}
// you can export function here
module.exports = {
    initializePayment
}



// uncomment this to execute with nodemon on the expressjs server

// call getAccessToken to generate access_token
// getAccessToken();

// call pay function after 5 seconds to use access_token generated by getAccessToken
// setTimeout(pay, 5000);