Krungsri (KMA)

Enable your customers to make payments using their KMA application right on mobile phone. Eliminating the need to enter their card details can help your customers checkout faster.

This guide walks you through the payment flow and details on how to implement.

The customer is required to have a mobile application KMA.

How to enable

• Supported Countries: Thailand
• Minimum API version: 2017-11-02

To enable Krungsri (KMA), send an email requesting this feature to support@opn.ooo. You will need to review and accept new terms and conditions.

Payment flow

Customers paying via Mobile Banking go through an off-site payment flow. This means that once the charge is created, it can only be authorized via the corresponding Bank’s application. The customer must authorize the payment using that banking app on their phone, to complete the flow.

After the customer selects Mobile Banking as their preferred payment method, your site should redirect to the bank’s application by using the resulting URI (a “deep link” that will automatically open the installed handler app). The following screenshots demonstrate completing payment flow using a mobile browser. The customer must pay via the bank's app to complete the payment.

Using a mobile browser

The customer chooses to pay with mobile banking ❶.The customer chooses the bank they want to pay with ❷. The payment details are shown, they then confirm the payment using their mobile phone ❸. The customer can choose to be redirected to the merchant's confirmation details page by pressing on Back to merchant ❹. Customer is redirected to merchant's website ❺.

Implementation

To create a charge using Krungsri (KMA), make the following API requests.

1. Create a new payment source (type: mobile_banking_bay) using Omise.js or one of the mobile SDKs (iOS and Android)
2. Create a new charge using the identifier of the source created in Step 1.
3. After receiving the charge completion webhook event, retrieve the charge to verify its status (optional, but recommended).

Use your public key to create the Krungsri (KMA) source on the client (a customer's browser or mobile phone). Use your secret key to create the Krungsri (KMA) charge on the server.

If both the creation and charge of a source must happen server-side, you can create and charge the source in a single API request using your secret key.

Creating a source

When the customer confirms that they wish to pay with this payment method, create a new source specifying the amount, currency, platform_type, and type.

The following examples demonstrate the creation of a new Krungsri (KMA) source for ฿1500. Replace the omise_public_key and $OMISE_PUBLIC_KEY variables with the test public key found on your dashboard.

Using Omise.js, the type parameter is supplied as the first argument to the createSource method.

Omise.setPublicKey(omise_public_key);

Omise.createSource('mobile_banking_bay', {
  "amount": 150000,
  "currency": "THB",
  "platform_type": "IOS"
}, function(statusCode, response) {
  console.log(response)
});

For testing, you can create the same request using curl.

curl https://api.omise.co/sources \
  -u $OMISE_PUBLIC_KEY: \
  -d "amount=150000" \
  -d "currency=THB" \
  -d "type=mobile_banking_bay" \
  -d "platform_type=IOS"

{
  "object": "source",
  "id": "src_test_5xkcm7v8akb5xnepnkm",
  "livemode": false,
  "location": "/sources/src_test_5xkcm7v8akb5xnepnkm",
  "amount": 150000,
  "barcode": null,
  "bank": null,
  "created_at": "2023-10-26T15:47:28Z",
  "currency": "THB",
  "email": null,
  "flow": "app_redirect",
  "installment_term": null,
  "ip": null,
  "absorption_type": null,
  "name": null,
  "mobile_number": null,
  "phone_number": null,
  "platform_type": "IOS",
  "scannable_code": null,
  "billing": null,
  "shipping": null,
  "items": [],
  "references": null,
  "provider_references": null,
  "store_id": null,
  "store_name": null,
  "terminal_id": null,
  "type": "mobile_banking_bay",
  "zero_interest_installments": null,
  "charge_status": "unknown",
  "receipt_amount": null,
  "discounts": []
}

The id attribute is the source identifier (begins with src).

Creating a charge

Create a charge specifying the parameters return_uri, source, amount, and currency.

• return_uri specifies the location on your website to which the customer should be redirected after completing the payment authorization step.
• source specifies the source identifier.
• amount and currency must match amount and currency of the source.

By default, the charge expires 15 minutes after creation.

The following example demonstrates how to create a new charge using curl. Replace $OMISE_SECRET_KEY with your test secret key found on your dashboard. Replace $SOURCE_ID with the id of the source.

curl https://api.omise.co/charges \
  -u $OMISE_SECRET_KEY: \
  -d "amount=150000" \
  -d "currency=THB" \
  -d "return_uri=https://example.com/orders/345678/complete" \
  -d "source=$SOURCE_ID"

{
  "object": "charge",
  "id": "chrg_test_5xkcm7za6qgtfifwi34",
  "location": "/charges/chrg_test_5xkcm7za6qgtfifwi34",
  "amount": 150000,
  "net": 148930,
  "fee": 1000,
  "fee_vat": 70,
  "interest": 0,
  "interest_vat": 0,
  "funding_amount": 150000,
  "refunded_amount": 0,
  "transaction_fees": {
    "fee_flat": "10.0",
    "fee_rate": "0.0",
    "vat_rate": "7.0"
  },
  "platform_fee": {
    "fixed": null,
    "amount": null,
    "percentage": null
  },
  "currency": "THB",
  "funding_currency": "THB",
  "ip": null,
  "refunds": {
    "object": "list",
    "data": [],
    "limit": 20,
    "offset": 0,
    "total": 0,
    "location": "/charges/chrg_test_5xkcm7za6qgtfifwi34/refunds",
    "order": "chronological",
    "from": "1970-01-01T00:00:00Z",
    "to": "2023-10-26T15:47:29Z"
  },
  "link": null,
  "description": null,
  "metadata": {},
  "card": null,
  "source": {
    "object": "source",
    "id": "src_test_5xkcm7ki2fbhu6c6ttu",
    "livemode": false,
    "location": "/sources/src_test_5xkcm7ki2fbhu6c6ttu",
    "amount": 150000,
    "barcode": null,
    "bank": null,
    "created_at": "2023-10-26T15:47:27Z",
    "currency": "THB",
    "email": null,
    "flow": "app_redirect",
    "installment_term": null,
    "ip": null,
    "absorption_type": null,
    "name": null,
    "mobile_number": null,
    "phone_number": null,
    "platform_type": "IOS",
    "scannable_code": null,
    "billing": null,
    "shipping": null,
    "items": [],
    "references": null,
    "provider_references": {
      "reference_number_1": "4K58jpBHjbtSA50R",
      "reference_number_2": null
    },
    "store_id": null,
    "store_name": null,
    "terminal_id": null,
    "type": "mobile_banking_bay",
    "zero_interest_installments": null,
    "charge_status": "pending",
    "receipt_amount": null,
    "discounts": []
  },
  "schedule": null,
  "customer": null,
  "dispute": null,
  "transaction": null,
  "failure_code": null,
  "failure_message": null,
  "status": "pending",
  "authorize_uri": "https://pay.omise.co/payments/pay2_test_5xkcm7zc3nhc29qaehc/authorize",
  "return_uri": "https://example.com/orders/345678/complete",
  "created_at": "2023-10-26T15:47:29Z",
  "paid_at": null,
  "expires_at": "2023-11-02T15:47:29Z",
  "expired_at": null,
  "reversed_at": null,
  "zero_interest_installments": false,
  "branch": null,
  "terminal": null,
  "device": null,
  "authorized": false,
  "capturable": false,
  "capture": true,
  "disputable": false,
  "livemode": false,
  "refundable": false,
  "partially_refundable": false,
  "reversed": false,
  "reversible": false,
  "voided": false,
  "paid": false,
  "expired": false
}

Creating a source and charge

Alternatively, you can create and charge a source in a single API request.

curl https://api.omise.co/charges \
  -u $OMISE_SECRET_KEY: \
  -d "amount=150000" \
  -d "currency=THB" \
  -d "return_uri=https://example.com/orders/345678/complete" \
  -d "source[type]=mobile_banking_bay" \
  -d "source[platform_type]=IOS"

Manually expiring the link

By default, the link expires 15 minutes after creation. If you wish to expire the link before that period ends, use the following API request to deactivate it.

curl https://api.omise.co/charges/$CHARGE_ID/expire \
  -X POST \
  -u $OMISE_SECRET_KEY:

Completing the charge

At this point, you have created a new charge with its status set to pending. Other possible values for charge status are successful, failed, and expired.

The following sections detail how to authorize a charge, receive its completion webhook event, and update its status.

Authorizing the charge

Redirect the customer to the location specified in authorize_uri so that they can authorize the charge.

The merchant can simulate this authorization phase in test mode by visiting authorize_uri to manually mark the charge as Successful or Failed.

After the customer has completed the authorization phase, they will be redirected to the location specified in return_uri.

Receiving the charge completion event

The best way to be notified about the completion of a charge is using webhook events.

Set up a location on the merchant server to receive webhook events, and add this location as a webhook endpoint on the dashboard.

Checking the charge status

After receiving this event, retrieve the charge using its id and confirm that its status matches the status of the charge contained in the event.

If the value of status is successful, you got paid.

If the value of status is failed, check the failure_code and failure_message in the charge object for an explanation.

Possible failure codes are as follows.

Mobile Banking charges cannot be voided or refunded through Opn Payments.

Limits

• Minimum: 2000 (THB20.00)
• Maximum: 15000000 (THB150,000.00)

Related API documentation

• Charge
• Source
• Webhook

How to check the public key and secret key

For information on how to obtain and check the public and secret keys, please refer to this document.