In this post we are going to see bKash PGW integration in Angular8, ASP.Net Core Webapi.

The Basic Flow:

• Create Grant token by calling token API
• Then call create payment API with information
• Then invoke bKash wallet authentication iframe
• Pass the authentication by providing Wallet number, OTP and PIN
• Get a callback in execute
• Then call execute API

Request for merchant credentials to bKash.

• app_key : “YOUR_APP_KEY”
• app_secret : “YOUR_SECRET_KEY”
• username : “YOUR_MERCHANT_USERNAME”
• password : “YOUR_MERCHANT_PASSWORD”

Back-End

Please overview: https://developer.bka.sh/docs also go through: https://developer.bka.sh/reference

Grant Token:

// GET api/bKash/getbKashToken
[HttpGet("[action]")]
public async Task

Create Payment:

// POST:  api/bKash/createPayment
[HttpPost("[action]")]
public async Task

Execute Payment:

// POST: api/bKash/executePayment
[HttpPost("[action]")]
public async Task

Please follow:

Front-End

Generate authorization token by calling back-end.

//Generate bKash Authorization Token
genToken() {
    let result: any;
    this._dataService.get(this._genTokenUrl)
        .subscribe(response => {
            result = response;
            let resdata = result.resdata;
            if (resdata!= null)
                this.initBkash(resdata);            
        }, error => {
            console.log(error);
        });    
}

bKash checkout process.

//bKash Checkout
initBkash(resdata) {
    let dataService = this._dataService;
    let bkPayCreateUrl = this._bkPayCreateUrl;
    let bkPayExecuteUrl = this._bkPayExecuteUrl;

    //Pay Amount
    let amount = 231.00; //Change Amount

    //Authorization Token
    this.token = JSON.parse(resdata.authToken).id_token;

    //Create PaymentModel
    let createPayModel = {
        authToken: this.token,
        amount: amount,
        intent: resdata.intent,
        currency: resdata.currency,
        merchantInvoiceNumber: resdata.merchantInvoiceNumber
    };

    //Execute PaymentModel
    let executePayModel = {
        authToken: this.token,
        paymentID: null
    };

    //Init bKash
    bKash.init({
        paymentMode: 'checkout', 
        paymentRequest: {
            "amount": amount,
            "intent": resdata.intent,
            "currency": resdata.currency,
            "merchantInvoiceNumber": resdata.merchantInvoiceNumber
        },
        //Payment Process
        createRequest: function () {
            dataService.save(createPayModel, bkPayCreateUrl)
                .subscribe(response => {
                    var data = JSON.parse(response.resdata);
                    if (data && data.paymentID != null) {
                        executePayModel.paymentID = data.paymentID;

                        //Call iFrame
                        data.errorCode = null;
                        data.errorMessage = null;
                        bKash.create().onSuccess(data);
                    }
                    else {
                        bKash.create().onError(); 
                    }
                }, error => {
                    bKash.create().onError(); 
                });
        },
        //Payment Execute
        executeRequestOnAuthorization: function () {
            $('#payment_status').val('');
            dataService.save(executePayModel, bkPayExecuteUrl)
                .subscribe(response => {
                    $('#close_button').click();
                    this.result = JSON.parse(response.resdata);
                    if (this.result && this.result.paymentID != null) {
                        $('#bKashFrameWrapper').fadeOut(); 

                        //Save to Database
                        localStorage.setItem('paymentresult', JSON.stringify(this.result));
                        $('#hiddenButton').click();
                    } else {
                        bKash.execute().onError();                      
                    }
                }, error => {
                    bKash.execute().onError(); 
                });
        },
        //On Success
        onSuccess: function(){},
        //Close
        onClose: function () {}
    });

    $('#bKash_button').removeAttr('disabled'); 
}

Finally save transaction details to database

savePayment() {
    var paydata = JSON.parse(localStorage.getItem('paymentresult'));
    this.transResult = JSON.stringify(paydata);
    if(paydata!=null)
    {
        this._dataService.save(paydata, this._bkPaySaveUrl)
            .subscribe(response => {
                if(response != null) 
                    alert(response.resdata);
            }, error => {
                console.log(error);
            }); 
            
        localStorage.removeItem('paymentresult');
    }
}

Payment will complete after pass the authentication by providing wallet number, OTP, PIN.

Download/clone full source code from Hope this will help 🙂