Payment Link Integration

Overview

This section enabled developers to integrate AXS Payment Link with their app/web to start collecting payments via redirection to AXS Hosted Payment Page (HPP).

If you prefer to generate QR code for customer-facing kiosk where users can easily scan a code to initiate payments using various banking apps, please click HERE.

Prerequisites: Do complete your Merchant Branding and get your Payment Link ready as the base URL.

Choose Link Type - Redirect to Payment Page when generating payment link.
The payment link generated should be similar to this https://{domain}/hpp/checkout/G_587G7D

Generating Client ID and Secret

Before integrating with AXS Checkout, it is essential to understand how AXS authenticate you and how the data is protected.
AXS uses Client ID and Secret to authenticate you and encrypt your payload to keep your data safe.
Follow the steps to generate Client ID and Secret:

Navigate to Developer page

Click 'Create' button on top right corner to create new credential

You may input the application name that is easy to recognise and represent your application.

Client ID and Secret should be kept confidential and only stored on your servers. Do not store them on your mobile or web client

Start Integrating

Starts your integration into your application in 3 + 1 optional steps:

1. Generate Complete Payment Link

Generate a complete payment link with user's payment information.

2. Redirect to Checkout Page

Once the complete payment link is ready, redirect user to AXS Checkout page.

3. Handle Webhook

After the payment is processed, webhook will be sent for payment notifications.

Optional: Payment Using Token

If you have collected token from customer's card, you will be able to charge the cardholder anytime by calling the payment API.

Step 1: Generate Complete Payment Link

This is the first step of the payment flow. Once you have the base payment link, client id and secret, follow this instruction to generate a complete payment link.

Endpoint

UAT

Production

GET https://checkout.svc.uat.pay.axs.com.sg/hpp/checkout/{merchantLinkId}?data={JWE compact serialization}

AXS uses JSON Web Encryption (JWE) to encrypt the request parameters. Do refer below for the JWE header info:

alg	PBES2-HS512+A256KW
enc	A256GCM
p2s	Salt (UUID)
p2c	Iteration (fixed value: 1000)
kid	Client ID

Request Parameters

Parameters	Required	Remarks
clientId		The Client ID generated in Merchant Portal
amount		Payment amount in cents. 1. Example: 100 = $1.00 2. Max amount = $9,999,999.00 3. Amount preset in Merchant Portal will be used if not specify
currency		Default is `SGD` Currently only support SGD.
merchantRef		Merchant's unique merchant reference. Max 40 characters.
scheme		- Available values: `credit_card`, `paynow`, `alipay`, `wechatpay` - Accepts multiple values separated by comma. - If not specified, default will be all available schemes.
terminalId		Merchant's input information. To be displayed in Merchant Portal.
webhookUrl		This URL will overwrite preset URL in Merchant Branding.
successUrl		This URL will overwrite preset URL in Merchant Branding.
failUrl		This URL will overwrite preset URL in Merchant Branding.
isTokenCreate		To define if requires AXS to return customer's card token to merchant. Default : `false`
merchantTransactionId		If provided, this will be used as the unique transaction id sent to payment gateway. This value will also be used for idempotency check to avoid duplicated payments.

Sample Request Data

{"clientId": "5fc53a20-e563-4f45-8dcc-4fd1f20f649c", "amount": "1023", "currency": "SGD", "merchantRef": "Ref123", "scheme": "", "terminalId": "Terminal-1", "webhookUrl": "https://webhook.site/", "successUrl": "https://axs.com.sg?session=243556", "failUrl": "https://axs.com.sg?session=243556", "isTokenCreate": true, "merchantTransactionId": "8743567837453758"}

Sample Code

Sample Final URL

Step 2: Redirect to Checkout Page

After the complete payment link is generated, navigate your user to the URL, and AXS will take care of the rest of the flow.

Step 3: Handle Webhook

Once the payment is completed, the user will be navigated back to the “successUrl/failUrl” that was configured in the Merchant Branding or during the payment request in Step 1, along with the status.
From backend, there is also a webhook notification from AXS' server to your server about the payment confirmation via POST method.

Please be advised to mark your order as paid ONLY after the webhook is received and validated.

Webhook Parameters

The following fields are sent with the webhook request:

Parameters	Required	Remarks
amount		Payment amount in dollar. Example: 101.01
currency		Default is `SGD` Currently only support SGD.
transactionRef		AXS' unique transaction reference or echo from `merchantTransactionId`. Example: 1448241333514969089
merchantRef		Merchant's unique merchant reference from Step 1.
status		Payment status: SUCCESS - Payment successful. DECLINED - Payment declined. Applicable to card payment. EXPIRED - QR code expired. Applicable to QR payment. Use the reserved amounts provided to simulate.
responseCode		Payment response code from Card Issuing Bank. Example: `00` - payment successful Other codes - unsuccessful Note: Empty value for QR payment.
paymentScheme		Payment scheme. Available value: VISA / MASTERCARD / PAYNOW / ALIPAY / WECHATPAY
paymentDateTime		Payment date time in (ISO 8601) standard. Example: 2025-12-10T09:14:01.201466Z
token		Object list of token details. Will be returned by AXS if the `isTokenCreate` was set as `true` from the request.
token.tokenId		Card token to be stored by merchant for future payment.
token.scheme		VISA / MASTERCARD
token.maskedPan		Masked card number. Example : 411111XXXXXX1111
token.expiry		Card expiry Example : 0139

After received webhook from AXS, decrypt the JWE payload using the same secret key used for encryption in Step 1.

Sample Response Data

{"amount":"10.23","currency":"SGD","transactionRef":"1428191406936641536","merchantRef":"Ref123","status":"SUCCESS","responseCode":"00","paymentScheme":"VISA","paymentDateTime":"2026-01-16T01:22:46.010508Z","token":{"tokenId":"5715E518056B491AE063AF598E0A2256","scheme":"VISA","maskedPan":"411111XXXXXX1111","expiry":"0139"}}

Sample Code

Optional : Payment Using Token

If you have set isTokenCreate as true in Step 1 and received the token details in Step 3, you will be able to charge the cardholder anytime by calling the payment API.

Endpoint

UAT

Production

POST https://member.uat.pay.axs.com.sg/api/hpp/v2/payment/pay

Request Body

Schema

{
  "data": "string (JWE compact serialization)"
}

AXS uses JSON Web Encryption (JWE) to encrypt the request parameters. Do refer below for the JWE header info:

alg	PBES2-HS512+A256KW
enc	A256GCM
p2s	Salt (UUID)
p2c	Iteration (fixed value: 1000)
kid	Client ID

Request Parameters

Parameters	Required	Remarks
token		Token of card received from webhook.
merchantTransactionId		Unique transaction id set by merchant to be sent to payment gateway. This value will also be used for idempotency check to avoid duplicated payments. Max 40 characters.
merchantRef		Merchant's unique merchant reference. Max 40 characters.
webhookUrl		This URL will overwrite preset URL in Merchant Branding. Refer Step 3 for the webhook handling and format details.
terminalId		Merchant's input information. To be displayed in Merchant Portal.
paymentTokenParams		Object list of payment token parameters
paymentTokenParams.amount		Payment amount in cents. 1. Example: 100 = $1.00 2. Min $0.01 and max amount = $9,999,999.00
paymentTokenParams.currency		Payment currency (e.g., SGD) based on ISO 4217 Currently only support SGD.

Sample Request Data

{"token": "5715E518056B491AE063AF598E0A2256", "paymentTokenParams": {"amount": 100, "currency": "SGD"}, "merchantTransactionId": "MyUniqID12345", "capture": true, "merchantRef": "MyRef09876", "webhookUrl": "https://webhook.site/", "terminalId": "Terminal-ABC"}

Sample Final URL

Response Parameters

Parameters	Remarks
paymentTransactionId	AXS internal payment trans Id.
status	SUCCESS / DECLINED
processorInformation	Object list of response from payment gateway.
processorInformation.approvalCode	Gateway approval code.
processorInformation.responseCode	Gateway response code. 00 - Success

processorInformation.retrievalReferenceNumber	Gateway RRN
processorInformation.merchantReference	From merchantRef parameter
processorInformation.merchantTransactionId	Unique transaction id set by merchant sent to payment gateway.
processorInformation.maskedPan	Masked card number. Example : 411111XXXXXX1111
processorInformation.expiry	Card expiry. Can be empty.
processorInformation.brand	VISA / MASTERCARD

Sample Response Data

{"paymentTransactionId": "7846203159486310203814", "processorInformation": {"approvalCode": "808280", "brand": "VISA", "expiry": "", "maskedPan": "411111XXXXXX1111", "merchantReference": "MyRef09876", "merchantTransactionId": "MyUniqID12345", "responseCode": "00", "retrievalReferenceNumber": "620207726401"}, "status": "SUCCESS"}

Congrats! You have now successfully completed the integration to AXS Checkout HPP.

Overview#

Generating Client ID and Secret#

Start Integrating#

Step 1: Generate Complete Payment Link#

Endpoint#

Request Parameters#

Step 2: Redirect to Checkout Page#

Step 3: Handle Webhook#

Webhook Parameters#

Optional : Payment Using Token#

Endpoint#

Request Body#

Schema#

Request Parameters#

Response Parameters#

Overview

Generating Client ID and Secret

Start Integrating

Step 1: Generate Complete Payment Link

Endpoint

Request Parameters

Step 2: Redirect to Checkout Page

Step 3: Handle Webhook

Webhook Parameters

Optional : Payment Using Token

Endpoint

Request Body

Schema

Request Parameters

Response Parameters