Cancel API Tutorial

This tutorial gives a stepwise approach to call the Cancel API.

  • The customer uses a digital wallet to pay for the items of purchase.
  • The merchant selects “digital wallet” and the Point-of-Sale calls Pockyt’s /add API to generate a transaction object.
  • The customer finds that they are unable to generate a QR code for the merchant to scan due to a lack of connectivity (or another issue).
  • The merchant will then select “cancel” in the Point-of-Sale system by calling Pockyt’s /cancel API. The cancel API allows for canceling a payment transaction. This applies to transactions that are abandoned before submission.
  • Pockyt notifies the digital wallet server to abandon the transaction.
  • The digital wallet server responds by canceling the transaction and notifying Pockyt of the cancellation status.
  • Pockyt will then relay the information to the Point-of-Sale.
// POCKYT ADD API sandbox example  
// Import crypto for MD5 hash calculation

var crypto = require('crypto');

// Assign all Sanbox parameters

var URL = "<"> ;  
var merchantNo = "200043" ;  
var storeNo = "303660" ;  
var MyToken = "359c05eb811c7c8576f4a8a277dc6f6b" ;

// construct POS fields and assign to object  
var myPOSParamObject = {  
    merchantNo: merchantNo,  
    storeNo: storeNo,  
    refundAmount: "10",  
    currency: "USD",  
    settleCurrency: "USD",  
    transactionNo: "316129873376769782",  

// Calculate the VeriSign signature:

var MySignature = CalculateSignature(MyToken, myPOSParamObject)

// Add the signature to the POS parametes so we  
// can use it in the body of the API call

var MyPocketParamObject = {  
        merchantNo: myPOSParamObject.merchantNo,  
        storeNo: myPOSParamObject.storeNo,  
        verifySign: MySignature,  
        refundAmount: myPOSParamObject.refundAmount,  
        currency: myPOSParamObject.currency,  
        settleCurrency: myPOSParamObject.settleCurrency,  
        transactionNo: myPOSParamObject.transactionNo  

// function that calculates the signature according to Pockyt rules  
function CalculateSignature(token,parameters)  
 // calculate the hash value of the token

var ApiTokenHashvalue = crypto.createHash('md5').update(token).digest("hex")

 // order parameters alfabetically  
 var SortedParams = sortObj(parameters);

 // Concatenate: add '&' between key and value pair and replace : for =  
 var MyString = '' ;  
 for (const [key, value] of Object.entries(SortedParams)) {  
 MyString += (`${key}=${value}&`);}

 // add hash value of token at the and of the string  
 MyString += ApiTokenHashvalue ;

 // create the verifySign

 const MySignature = crypto.createHash('md5').update(MyString).digest("hex");

 return MySignature;

// algabetical sort helper function  
 function sortObj(obj) {  
 return Object.keys(obj).sort().reduce(function (result, key) {  
 result[key] = obj[key];  
 return result;  
 }, {});  

// Prepare JASON that will be used in the body of the API call

var MyPocketParamJason = JSON.stringify(MyPocketParamObject);  

fetch(URL, {  
 method: "POST",  
 headers: {  
 "Content-Type": "application/json"  
 body: MyPocketParamJason  
.then(response => response.json())  
.then(data => console.log(data))  
.catch(error => console.error(error));