SDK Parameter Reference

Field	Type	M/O	Description
type	String	M	Fixed value: `payment`
sessionID	String	M	The sessionID returned by the interaction (LinkPay) API (16-character UUID in current LinkPay URL)
locale	String	O	Language for Drop-in display. Example: `en-US`. Supports Chinese, Traditional Chinese, English, Japanese, Thai
environment	String	M	Set the environment for requests, e.g., `HKG_prod`, `BKK_prod`, `TYO_prod`, `UAT`, `TEST`
mode	String	M	`fullPage` or `embedded`
appearance	Object	O	Customize Drop-in appearance
colorAction	String	O	Checkbox or clickable button color, hex code (e.g., `#5E48FC`)
colorBackground	String	O	Drop-in background color, hex code
colorBoxStroke	String	O	Border/line color, hex code
colorDisabled	String	O	Disabled button color, hex code
colorError	String	O	Error border and text color, hex code
colorFormBackground	String	O	Input background color, hex code
colorFormBorder	String	O	Input border color, hex code
colorInverse	String	O	Button text color, hex code
colorBoxFillingOutline	String	O	Input border when selected, hex code
colorPlaceholder	String	O	Input placeholder color, hex code
colorPrimary	String	O	Primary font color, hex code
colorSecondary	String	O	Secondary font color, hex code
button/font	Object	O	Button font style
heading/font	Object	O	Heading font style
subHeading/font	Object	O	Subheading font style
headingPopup/font	Object	O	Popup heading font style
label/font	Object	O	Label font style
labelInfo/font	Object	O	Label info font style
labelPopup/font	Object	O	Popup label font style
inputField/font	Object	O	Input field font style
inputFieldInfo/font	Object	O	Input field info font style
inputFieldPopup/font	Object	O	Input field popup font style
paragraph/font	Object	O	Paragraph font style
placeholder/font	Object	O	Input placeholder font style
borderRadius	Array	O	Page corner radius `[radius1, radius2, radius3, radius4]`
logoPosition	String	O	Merchant logo position: `left`, `middle`, `right`. Default: `left`

`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