API Preface

Identification and authentication of the caller

All requests must include an Authorization header with the API key issued by Gate for the specific merchant connection point (merchant terminal):

Authorization: Bearer <MERCHANT_API_KEY>.

Idempotency

referenceId is treated as the unique request identity per merchant terminal. Re-registering a create payment or create payout with an already used referenceId is treated as a duplicate and returns duplicate_request.

Error Handling

Generic error envelope with fields code, name, and English description is used for non-200 responses:

{
 "code": "1004",
 "name": "duplicate_request",
 "description": "Duplicate request."
}

Receiving such a response from the system indicates that the request was unsuccessful.

A response with an HTTP code other than 200 but without a body may be received from the infrastructure, not from the Gate system. This response does not indicate that the request was unsuccessful. To obtain accurate payment status information, you should explicitly request the payment/payout status.

Error codes

Code	Name	Description
1000	processing_error	Processing Error.
1002	incorrect_request	The request parameters didn’t validate.
1003	unauthorized	Unauthorized access. Credentials missing or invalid.
1004	duplicate_request	Duplicate Request.
1005	payment_method_not_supported	Payment method is not supported.
1006	currency_not_supported	Currency is not supported.
1007	invalid_currency	The currency value specified is not valid.
1008	invalid_amount	The amount value specified is not valid.
1009	interface_operation_not_supported	The operation is not supported for the interface.
1010	bin_not_found	No card scheme found for provided BIN value.
1104	payment_not_found	Payment not found for provided identity value.
1105	invalid_payment_state	The payment is in a state that does not allow this operation.
1106	payout_not_found	Payout not found for provided identity value.
3001	declined_by_acquirer	Declined by acquirer.
4001	declined_by_issuer	Declined by issuer.
4002	issuer_insufficient_funds	Insufficient funds.
4003	issuer_invalid_card_number	Card number is invalid.
4004	issuer_card_expired	Card is expired.
4005	issuer_limits_reached	Issuer limits are reached.
4006	issuer_card_stolen	Card is declined by issuer.
4007	issuer_invalid_security_code	Invalid security code.
5001	declined_by_3ds	Declined by 3DS.
7001	declined_by_antifraud	Declined by antifraud.