Debit Lien

Create a Post endpoint on your application with the path /lien/debit. This endpoint is crucial for completing dual messaging, specifically for debiting the wallet when a lien is in place. It would be good to note that the amount in the debit lien request can differ from the amount placed on the lien.

This means that there are 3 main cases here and each of these cases is handled differently as explained below ;

Where the debit lien amount is equal to the amount placed on the lien: When the debit lien amount is equal to the amount placed on a lien, then the amount is just debited.
Where the debit lien amount is greater than the amount placed on the lien: In this case, the customer’s total balance (balance + amount placed on the lien) is computed and if this total balance is greater than or equal to the debit lien amount, then the amount is debited and a success response code is returned. But if this total balance is less than the debit lien amount, then an insufficient fund response is returned.
Where the debit lien amount is lesser than the amount placed on the lien: In this case, the debit lien amount is just debited from the placed lien, and the remaining lien amount is returned to the customer’s balance. A special case of this can be when the debit lien amount is 0, this is also very possible and is how the placed lien is reverted. In the case of a 0 amount, the placed lien is removed and the placed lien amount is added back to the customer’s balance.

📘
Make sure to read the following information since you'll probably encounter it in this section

Auth and MAC Generation

Response Code

Understanding Dual Messaging

Terminal Type

Additional Fields

Request

Attribute	Type	Description	Required
requestId	String	A unique ID for every request sent across. Very necessary for the mac	True
walletId	String	The wallet ID of the wallet to debit lien on	True
amount	Long	The actual amount to be debited. The amount can also be 0, in which case the lien is removed and no value is debited.	True
transactionReference	String	The reference that can be used to retrieve the transaction. The transaction reference is the same as the transaction reference of the request that places the lien.	True
mac	String	The hash included in every request is used to make sure the request is from the actual source and has not been tampered with	True
transactionDateTime	LocalDateTime	This is the date and time the transaction occurred	False
terminalId	String	This is an identifier for the terminal the transaction came from	True
terminalType	String	A 2-digit string that defines the type of terminal.	True
merchantId	String	The merchant that accepted the card	True
acquiringInstitutionId	String	An ID to identify the institution that acquired the transaction	False
currencyCode	String	A code that identifies the currency the transaction was done on	True
cardAcceptorNameLocation	String	The name and location of the card acceptor	True
rrn	String	This is the Retrieval Ref Number	True
stan	String	This is the System Trace Audit Number	True
transactionFee	Long	The transaction fee in minor	True
additionalFields	Map	Any other Iso field needed by a fintech	False

Request Mac

The request Mac is generated by concatenating the following attributes in the order which they occur, generating an HMAC using the shared private key, and getting the hex string of the result.

transactionReference, requestId, walletId, rrn, stan, amount, currencyCode

Response attributes

Attribute	Type	Description	Required
requestId	String	The request Id that came with the request.	True
responseCode	String	The code that signifies the status of the operation.	True
amount	Long	The amount that came with the request.	True
transactionReference	String	The reference that came with the request	True
mac	String	The hash included in every response is used to make sure the request is from the actual source it should be and has not been tampered with	True

Response Mac

The response Mac is generated by concatenating the following attributes in the order which they occur, generating an HMAC using the shared private key, and getting the hex string of the result.

transactionReference, requestId, responseCode

Sample requests

The sample requests for the debit only cover 3 scenarios. It should be noted that the difference between one response and another is just the response code. The response code table in section 4.0 can be used to know the response code that can be used for other scenarios that might not be covered in the sample requests.

Successful

Request

{
    "requestId": "1fds5d6f7g8hijokmojih6f5d",
    "walletId": "1234567894",
    "amount": 100,
    "transactionReference": "11123456789",
    "mac": "hexdigest",
    "transactionDateTime": "2020-05-15T13:32:09",
    "terminalId": "3IWPDVNA",
    "terminalType": "21",
    "merchantId": "WEBPAYDIRECTVNA",
    "acquiringInstitutionId": "428051043",
    "currencyCode": "566",
    "cardAcceptorNameLocation": "MATRIX ENERGY LIMITE   LA
    "rrn" : "000111000111",
    "stan" : "000018",
    "additionalFields=
        {
            "processingCode":"000000",
            "merchantType":"8850"
} }

Response

{
    "amount": 100,
    "responseCode": "00",
    "transactionReference": "11123456789",
    "requestId": "1",
    "mac": "hexdigest"
}

Invalid mac

Request

{
    "requestId": "1fds5d6f7g8hijokmojih6f5d",
    "walletId": "1234567894",
    "amount": 1000,
    "transactionReference": "11123456789",
    "mac": "hexdigest",
    "transactionDateTime": "2020-05-15T13:32:09",
    "terminalId": "3IWPDVNA",
    "terminalType": "21",
    "merchantId": "WEBPAYDIRECTVNA",
    "acquiringInstitutionId": "428051043",
    "currencyCode": "566",
    "cardAcceptorNameLocation": "MATRIX ENERGY LIMITE   LA LANG",
    "rrn" : "000111000111",
    "stan" : "000018",
    "additionalFields=
        {
            "processingCode":"000000",
            "merchantType":"8850"
} }

Response

{
  "amount": 1000,
  "responseCode": "12",
  "transactionReference": "11123456789",
  "requestId": "1",
  "mac": "hexdigest"
}

Insufficient funds

Request

{
    "requestId": "1fds5d6f7g8hijokmojih6f5d",
    "walletId": "1234567894",
    "amount": 1000,
    "transactionReference": "11123456789",
    "mac": "hexdigest",
    "transactionDateTime": "2020-05-15T13:32:09",
    "terminalId": "3IWPDVNA",
    "terminalType": "21",
    "merchantId": "WEBPAYDIRECTVNA",
    "acquiringInstitutionId": "428051043",
    "currencyCode": "566",
    "cardAcceptorNameLocation": "MATRIX ENERGY LIMITE   LA LANG",
    "rrn" : "000111000111",
    "stan" : "000018",
    "additionalFields=
        {
            "processingCode":"000000",
            "merchantType":"8850"
} }

Response

{
    "amount": 1000,
    "responseCode": "51",
    "transactionReference": "11123456789",
    "requestId": "1",
    "mac": "hexdigest"
}

📘Make sure to read the following information since you'll probably encounter it in this section

Response attributes

Sample requests

Successful

Invalid mac

Insufficient funds

📘
Make sure to read the following information since you'll probably encounter it in this section