Embedded QR Codes

Comprehensive guide on integrating and using Embedded QR Code payments through HitPay API.

Introduction

Embedded QR Code Payments allow seamless integration of QR payments directly into your platform without redirecting the users away.

Core Concept

At a high level, integrating payments into your system involves a 4-step process:

Create a Payment Request

The first step is to create a payment request in your system

Generate and Present the QR Code

Once the payment request is ready, generate and present the QR code to the user.

Client Scans and Initiates Payment

The client scans the QR code and initiates the payment through their banking app.

Handle Webhooks and Server Communication

After the payment is processed, handle webhooks to receive payment notifications and manage server-client communication.

Supported Methods

Please note that not all payment methods support embedded QR Codes. Here is the list of methods that support QR Codes:

Payment Method	Code
PayNow	paynow_online
ShopeePay	shopee_pay
QRIS	doku_qris (Indonesia merchants), ifpay_qris (other merchants)
WeChatPay	wechat_pay
VietQR	vietqr_payme
PromptPay	opn_prompt_pay
TrueMoney	opn_true_money_qr
GrabPay	grabpay_direct
GrabPay PayLater	grabpay_paylater
UPI	upi_qr
Gcash	gcash_offline
QRPH	qrph_netbank
Touch ‘n Go	touch_n_go
ShopBack	Coming Soon

Authentication

Before integration, it’s essential to understand how Hitpay APIs are authenticated. Hitpay utilizes API keys to grant access to the API. You can locate this key in your dashboard under “API keys.”

Hitpay requires the API key to be included in all API requests to the server. This key should be placed in a header that follows the format shown below:

X-BUSINESS-API-KEY: meowmeowmeow

PHP

$request->setHeaders(array(
  'X-BUSINESS-API-KEY' => 'meowmeowmeow',
  'Content-Type' => 'application/x-www-form-urlencoded',
  'X-Requested-With' => 'XMLHttpRequest'
));

API keys should be kept confidential and only stored on your servers. Do not store it on your mobile or web client

Step 1: Create a Payment Request

This is the first step of the payment flow. Once you have all the details from the user and are ready to collect payments, use this API to create a payment request.

Endpoint

POST /v1/payment-requests

Creates a payment request and generates a QR code for the paynow_online payment method.

Request Parameters

Parameter	Type	Description
amount	string	Required. The amount to be paid.
currency	string	Required. The currency of the payment (e.g., “sgd”).
payment_methods[]	array	Required. Specify paynow_online as the payment method.
generate_qr	boolean	Required. Set to true to generate the QR code.
name	string	Optional. The name of the customer.
email	string	Optional. The email of the customer.
phone	string	Optional. The phone number of the customer.
purpose	string	Optional. The purpose of the payment.
reference_number	string	Optional. A reference number for the payment.

Example Request

{
  "amount": "123.00",
  "currency": "sgd",
  "payment_methods": ["paynow_online"],
  "generate_qr": true,
  "expiry_date": "2024-06-01T14:37:11"
}

Response

The response will include a qr_code_data object, which contains the data to be converted into a scannable QR code (qr_code).

Example Response for Embedded QR Code Payment Request

{
  "id": "9c262fb5-f3cd-4187-8c3e-fbe20730b9c6",
  "name": null,
  "email": null,
  "phone": null,
  "amount": "123.00",
  "currency": "sgd",
  "is_currency_editable": false,
  "status": "pending",
  "purpose": null,
  "reference_number": null,
  "payment_methods": [
    "paynow_online"
  ],
  "url": "https://securecheckout.hit-pay.com/payment-request/@nitinmuthyala/9c262fb5-f3cd-4187-8c3e-fbe20730b9c6/checkout",
  "redirect_url": null,
  "webhook": null,
  "send_sms": true,
  "send_email": false,
  "sms_status": "pending",
  "email_status": "pending",
  "allow_repeated_payments": false,
  "expiry_date": null,
  "address": null,
  "line_items": null,
  "executor_id": null,
  "created_at": "2024-05-28T14:37:11",
  "updated_at": "2024-05-28T14:37:11",
  "qr_code_data": {
    "qr_code": "00020101021226550009SG.PAYNOW010120210201605883W030100414202405281445315204000053037025406123.005802SG5905Nitin6009Singapore62290125DICNP17168782314914MWULPX63043561",
    "qr_code_expiry": null
  }
}

Step 2: Generate and Present the QR Code

Once the payment request is created, generate the QR code using the response data and present it to the user.

Note for Sandbox Testing:

In sandbox, the qr_code value returned may be a URL (e.g. https://securecheckout.sandbox.hit-pay.com/...) instead of the raw PayNow QR string. This is intended to help you test the flow using a standard QR code reader or by visiting the link directly in a browser.
In production, the qr_code will be a raw PayNow payload string that you should convert into a scannable QR code for use with banking apps.

Step 3: Client Scans and Initiates Payment

The client scans the presented QR code with their banking app and initiates the payment process.

Step 4: Handle Webhooks and Server Communication

After the payment is processed, handle webhooks to receive payment notifications and manage server-client communication to update the payment status in your system.

What is a Webhook?

Webhook is a POST request sent from HitPay’s server to your server about the payment confirmation. If you are using hitpay APIs to integrate into your e-commerce checkout you must mark your order as paid ONLY after the webhook is received and validated.

Handling the webhook

• Create an endpoint (E.g. /payment-confirmation/webhook) in your server that accepts POST requests. This request is application/x-www-form-urlencoded.
• Validate the webhook data using your salt value
• Return HTTP status code 200 to Hitpay
• Mark your order as paid
• Sample webhook payload data

Sample Webhook Payload

payment_id=92965a2d-ece3-4ace-1245-494050c9a3c1&payment_request_id=92965a20-dae5-4d89-a452-5fdfa382dbe1&reference_number=ABC123&phone=&amount=599.00&currency=SGD&status=completed&hmac=330c34a6a8fb9ddb75833620dedb94bf4d4c2e51399d346cbc2b08c381a1399c

Webhook fields

Following fields are sent with the webhook request:

Parameter	Description
payment_id	Payment ID
payment_request_id	Payment request ID
phone	Buyer’s phone number
amount	Amount related to the payment
currency	Currency related to the payment
status	Payment status (completed / failed)
reference_number	Arbitrary reference number mapped during payment request creation
hmac	Message Authentication code of this webhook request

Validating a Webhook

To validate a webhook payload from HitPay, follow these steps:

1. Payload Extraction: Extract the key-value pairs from the webhook payload. For example:

payment_id=92965a2d-ece3-4ace-1245-494050c9a3c1&payment_request_id=92965a20-dae5-4d89-a452-5fdfa382dbe1&reference_number=ABC123&phone=&amount=599.00&currency=SGD&status=completed&hmac=330c34a6a8fb9ddb75833620dedb94bf4d4c2e51399d346cbc2b08c381a1399c

2. Exclude HMAC and Values: Remove the "hmac" key and its corresponding value from the extracted payload. For example:

3. Concatenation and Sorting: Concatenate the keys and values from the remaining key-value pairs without using "&" and "=", and arrange them in alphabetical order of the keys. For example:

amount1.00currencySGDpayment_id91d94138-b0b5-4ba0-b78c-babc59776876payment_request_id91d94124-0d1c-4fb4-921e-51953793106cphonereference_number201000000Dstatuscompleted

4. Signature Generation: Use the HMAC-SHA256 algorithm along with the secret salt from your dashboard to generate a signature for the concatenated string. This signature will be unique to this payload.

5. Comparison and Validation: Compare the generated signature with the HMAC value present in the original payload, both values must match.

By following these steps, you can ensure the authenticity and integrity of the webhook payload received from HitPay. This process guarantees that the payload can be trusted and processed securely.

Sample Code

PHP

function generateSignatureArray($secret, array $args) {   
  $hmacSource = [];        
  foreach ($args as $key => $val) {
    $hmacSource[$key] = "{$key}{$val}";
  }
  ksort($hmacSource);
  $sig            = implode("", array_values($hmacSource));
  $calculatedHmac = hash_hmac('sha256', $sig, $secret); 

  return $calculatedHmac;
}

FAQs

Webhook Signature Mismatch?

Possible reasons for wrong hmac value generated

• Ensure that you are using the correct salt value from the correct environment (Sandbox or Production)
• Make sure NOT to include the hamc value when calculating the hmac
• Make sure all the values stated above are included in the payload including reference_number. Use an empty string if the value does not exist

Facing Invalid Business API Key Error

Possible reasons for this error:

• You are using a production key in the sandbox or a sandbox key in production. Make sure the API base URL is correct.
• You are missing headers. Ensure that you include both the ‘Content-Type’ and ‘X-Requested-With’ headers. Refer to this section again.

Product Checklist

Ensure the following before moving to production

• Change the base URL for all API calls to https://api.hit-pay.com/v1/
• Finish paynow and other payment methods set up in production
• Update API keys and Salt values from the production dashboard
• If you are using Drop-In UI, update the default link to the production URL

Why does my charges `webhook status` show as failed?

If you are using a payment plugin, after every successful payment, a webhook is sent to your store to acknowledge the payment confirmation. Your order is marked as paid through this webhook.

A webhook status showing as "failed" indicates that Hitpay failed to communicate with your server. This can happen for the following reasons:

• Your store may have a security feature that blocked Hitpay's request.
• Your server was unavailable during this time.

To avoid this issue, ensure that you whitelist Hitpay's IP addresses:

• Production: 3.1.13.32, 52.77.254.34
• Sandbox: 54.179.156.147

For further details, please review your store's debug logs.