Payment notice

C payment by VK Pay You may be notified of the result of the transaction (e.g., payment or refund).

In order to receive notifications,, connecting to the Payment System API Give the technical support the URL to which you want to receive notifications. You can give several addresses at once.

To change URLs or add new ones, write to technical support at vkpay_solutions@vk.team .

The notification must be processed and sent to the payment system a response with the result of processing: success or error. If you do not respond, the payment system will carry out the transaction, but will continue to send notifications, assuming that you have not processed the transaction.

Advice. We recommend that you keep these notifications on your side. They are useful for performing returns on unsuccessful transactions and for collecting statistics.

The payment system can send notifications from subnets: 176.112.170.160/29 , 188.93.57.60/32 , 188.93.57.3/32 , 188.93.57.39/32 , 188.93.57.33/32 , 188.93.57.38/32 , 188.93.57.50/32 .

The Interaction Scenario

1. 1.
   Get a notification .
2. 2.
   Check the signature of the notification .
3. 3.
   Handle the notification .
4. 4.
   Send a response to the payment system .

Step 1. Get a notification

After making a payment, the payment system will send a notification of the result of the transaction to the URL that you specified when connecting to VK Pay.

Notification is sent POST -request and contains three fields:

• •
  data JSON notification data encoded in the BASE64 string.
• •
  signature — signature of the notification .
• •
  version version of the API protocol.

Check authentication of Notification using the public key and process the data .

Example of notification

Step 2. Check the signature of the notification

The payment system generates a notification signature using OpenSSL (the RSA algorithm) using the system’s private key.

The signature of the payment notification is a field signature which contains the field data data BASE64 strings encoded using the RSA algorithm.

To verify the signature, use the public key that you received when you entered into a contract with the payment system operator.

Example of a public key

Example of verifying a notification signature in PHP

Step 3. Handle these notifications

Process the field data data .

Example of data in a structure data In the payment

Step 4. Send a response to the notification

For this purpose:

1. 1.
   Form the field data JSON notification data encoded in the BASE64 string. The structure depends on the result of processing the notification: successfully or unsuccessfully .
2. 2.
   Sign the Notice .
3. 3.
   Send a response to the payment system.

Example of response to a notification

Response to the notification

Structure of the response

The response to the JSON notification should include the fields:

• •
  version version of the protocol. The latest version: 2-03 .
• •
  data JSON notification data encoded in the BASE64 string.
• •
  signature — signature of response .

Field Formation data Successful processing of the notification

If the processing of the notification is successful, in response to the notification, send:

• •
  In the body of the answer body in the field notify_type One meaning: payment_delivered payment is made or payment_declined - payment denied.
• •
  In the title header in the field status meaning OK .

Example data Successful processing of the notification

Object Fields body Successful processing of the notification

Header Fields header Successful processing of the notification

Field Formation data Error handling the notification

If there was an error in processing the notification, in response to the notification, send:

• •
  In the body of the answer body in the field notify_type meaning TRANSACTION_STATUS .
• •
  in the title header : in the field error - code and description of the error, in the field status meaning ERROR . More specifically, in errors in Notification Processing .

Example data Error handling the notification

Object Fields body Error handling the notification

Header Fields header Error handling the notification

Notification Processing Errors error.code

Forming the signature of the notification response

Signing a response to a payment notification is a field signature which contains the result of the BASE64 string concatenation from the field encoded by the SHA256 cryptographic hashing algorithm in the HEX representation data The private key of the seller.

To sign the response to the notification:

1. 1.
   Form the field data .
2. 2.
   Encode the field data .
3. 3.
   Concatenate the field data with a private key .
4. 4.
   Compute the SHA256 cryptographic hash in the HEX representation .

Step 1. Form the field data

Field data A JSON object with a header and a request body. Structure data depends on the result of processing the notification: successfully or unsuccessfully .

Example data Successful processing of the notification

Step 2. Encode the generated field data in the BASE64 line

Example field data encoded in the BASE64 string

Step 3. Concatenate the BASE64 string obtained in the previous step with the seller’s private key

Example of field concatenation data and private key

Step 4. From the string obtained after combining, calculate the cryptographic hash SHA256 in the HEX representation

Done! Use the resulting value when sending a request in the parameter signature .

Example of the final result

Object Fields body In the payment notification

Object Fields body It depends on the transaction and the payment method.

Object Fields user_info

Object user_info It contains information about the payer. See other payment notification options in the section Object Fields body .

Object Parameters payment_info

Object payment_info contains data on the payment side of the payment system. See other payment notification options in the section Object Fields body .

Transaction Errors

Parameter decline_reason The payment notification may contain the following values: