SDK Event Reference

SDK Events are Zero Latency, client-side triggers that synchronize user website's UI with the payment lifecycle. it allows the frontend to instantly react to user actions—such as a BIN validation or a canceled window—ensuring a fluid user experience and status transpancy without page reloads in Drop-in.

SDK Events occur in Main Order Flow

`payment_completed`

Returned when the payment is successfully completed.

Merchants can use this event to update UI or notify users of a successful transaction.

Field	Type	M/O	Description
type	String	M	Fixed value: `payment_completed`
sessionID	String	M	Same as sessionID in the payment command
merchantTransID	String	M	Merchant transaction ID, used for querying order details
econtext	Object	O	Returned when independent payment method info needs to be displayed

`payment_failed`

Returned when the payment fails.

Merchants should display code or message to the user for further action.

Field	Type	M/O	Description
type	String	M	Fixed value: `payment_failed`
sessionID	String	M	Same as sessionID in the payment command
merchantTransID	String	O	Merchant transaction ID
code	String	O	Response code returned for failed payment
message	String	O	Response message returned for failed payment

`payment_not_preformed`

Drop-in uses this event for errors that occur before calling the payment API. Example: sessionID in the payment command does not exist or is invalid.

Also returned if Drop-in finds no available payment methods for the current order.

Field	Type	M/O	Description
type	String	M	Fixed value: `payment_not_preformed`
sessionID	String	M	Same as sessionID in the payment command
code	String	O	Standard V/B class response code
message	String	O	Standard V/B class response message

Standard Response Codes

Code	Message
V0000	field invalid format
V0001	field absent or empty
V0002	field invalid value
B2001	Session ID not found
B2002	Order has been paid
B2003	Order closed
B2004	Payment error
B2005	No available payment method
B2006	Payment failed (fallback code)

`payment_cancelled`

Returned when the user actively terminates the payment process in Drop-in.

Merchants should not treat this as a failed transaction. The transaction result must be verified via backend query.

Field	Type	M/O	Description
type	String	M	Fixed value: `payment_cancelled`
sessionID	String	M	Same as sessionID in the payment command

SDK Events occur in optional Order Flow

`payment_method_select`

It is available in Card Bin Verification Function, which can be optional set-up in SDK Initialization.Returned when merchant request isVerifyPaymentBrand: true in SDK and user enter card information in drop-in page

Merchants can use this event to receive the card information and control in SDK response to allow if the card able to proceed the payment

Field	Type	M/O	Description
type	String	M	Fixed value: `payment_method_selected`
verificationID	String	M	16-character UUID identifying the verification request
first6No	String	O	The first 6 digits of the card number
last4No	String	O	The last 4 digits of the card number
paymentBrand	String	O	The card brand (e.g., Visa, Mastercard, JCB)

Merchant response: dropInInstance.value.callbackVerification({msg: '',isVaild: '', id})

Field	Type	M/O	Description
msg	String	M	Custom message displayed to the user when isValid is false
isVaild	String	M	true or false
id	String	O	16-character UUID identifying the verification request