Webhook

Note that X-Iyz-Signature and X-Iyz-Signature-V2 will no longer supported. We expect our merchants to enhance their system to X-Iyz-Signature-V3 in timely manner.

iyzico uses webhooks to notify your application when the transaction is done. (Success, Failure) When a payment attempt is made, it is possible to receive the transaction result via HTTP POST notification. The first notification will be sent after 10-15 seconds of the initial payment attempt. It is a JSON Payload and server to server HTTP request. iyzico will keep continuing sending notifications every 15 minutes until your server responds with a status of "2xx". Notifications will stop after 3 attemps.

In iyzico, all of the payment methods operations results directly which towards the use of webhooks could be optional. For an instance, in a successful payment request, latest response contains all the payment details. However webhooks can still be used to trigger different mechanisms if desired.

In order to send the "X-IYZ-SIGNATURE-V3" value in the header, the webhook signature feature must be enabled on your account. To activate this feature, you can contact [email protected].

How to activate Webhooks?

After login to iyzico Merchant Portal, you can find the Webhook Notifications under the menu called "Settings" > "Merchant Settings" > "Merchant Notifications" (HTTPS URL is required)

Webhook Forms

Webhooks posts on 3 distinguishable formats;

• Direct Format

• HPP(Hosted Payment Page) Format

• Subscription

Direct Format

Following webhook format appears on NON-3DS and 3DS payment requests.

Parameter	Type	Description
paymentConversationId	string	Merchant's reference id for the related payment.
merchantId	string	Merchant's id, MID.
paymentId	string	Relevant paymentId which belongs to the payment.
status	string	Payment status. Values: FAILURE, SUCCESS, INIT_THREEDS, CALLBACK_THREEDS, BKM_POS_SELECTED, INIT_APM, INIT_CONTACTLESS
iyziReferenceCode	string	A unique reference code for the notification
iyziEventType	string	Shows the request type. Values: PAYMENT_API, API_AUTH, THREE_DS_AUTH, THREE_DS_CALLBACK, BKM_AUTH, BALANCE, CONTACTLESS_AUTH, CONTACTLESS_REFUND
iyziEventTime	long	Unix timestamp value of first notification.
iyziPaymentId	long	Relevant paymentId which belongs to the payment.

HPP Format

Similar to above, next webhook format appears on hosted page solutions which are PWI, CF.

Parameter	Type	Description
paymentConversationId	string	Merchant's reference id for the related payment.
merchantId	string	Merchant's id, MID.
token	string	The token generated for the related payment
status	string	Payment status. Values: FAILURE, SUCCESS, INIT_THREEDS, CALLBACK_THREEDS, BKM_POS_SELECTED, INIT_APM, INIT_BANK_TRANSFER, INIT_CREDIT, PENDING_CREDIT, INIT_CONTACTLESS
iyziReferenceCode	string	A unique reference code for the notification.
iyziEventType	string	Shows the request type. Values: CHECKOUT_FORM_AUTH, BANK_TRANSFER_AUTH, BKM_AUTH, BALANCE, CONTACTLESS_AUTH, CONTACTLESS_REFUND, CREDIT_PAYMENT_AUTH, CREDIT_PAYMENT_PENDING,CREDIT_PAYMENT_INIT, PWI_TKN_FUND, PWI_TKN_AUTH, PWI_TKN_THREEDS_AUTH
iyziEventTime	long	Unix timestamp value of first notification.
iyziPaymentId	long	Relevant paymentId which belongs to the payment.

Subscription Format

In the subscription feature, after the subscription is started, you can receive webhook notifications not only for the initial transaction but also for the recurring payments to be collected under the plan.

You can check the status of recurring payments by defining a URL in the subscription notification field located under "Settings > Merchant Settings > Merchant Subscription Notifications" in the iyzico control panel.

Example subscription notifications for successful and failed transactions are as follows.

Success

{
  "orderReferenceCode": "ae5fcbf8-4fd2-46e5-b199-8f690ae9fae5",
  "customerReferenceCode": "ff4052ca-0588-40eb-81a9-848c0c409472",
  "subscriptionReferenceCode": "ea0362e2-a1c4-4fda-89f0-3758a5c20a28",
  "iyziReferenceCode": "18d7cc48-a64b-4cd3-ae68-71aff1c76ed9",
  "iyziEventType": "subscription.order.success",
  "iyziEventTime": 1758704403161
}

Failure

{
  "orderReferenceCode": "9ed2d128-b106-464b-8170-84325e75703b",
  "customerReferenceCode": "042f0b61-079a-4a38-9454-6564a3c11a5a",
  "subscriptionReferenceCode": "b0f6d38f-b2d1-4a72-9bf2-bc9375665f3a",
  "iyziReferenceCode": "aac139a9-43db-4f40-82dd-d4e5a77a3d2e",
  "iyziEventType": "subscription.order.failure",
  "iyziEventTime": 1579612261619
}

Subscription Notification Parameters

Parameter	Type	Description
orderReferenceCode	String	The reference code of the related payment attempt. It is used in the retry process for failed transactions.
customerReferenceCode	String	The reference code of the customer.
subscriptionReferenceCode	String	The reference code of the subscription.
iyziReferenceCode	String	The unique iyzico reference code generated for the request.
iyziEventType	String	Specifies the request type. Possible values are: "subscription.order.success" "subscription.order.failure"
iyziEventTime	Long	The Unix timestamp value of when the notification was created.

Validation of Notifications

To verify source of webhook, iyzico sends encrypted a variable in the header called X-IYZ-SIGNATURE-V3 that can be decrypt with only merchants their own SECRET KEY.

Note that X-Iyz-Signature and X-Iyz-Signature-V2 will no longer supported. We expect our merchants to enhance their system to X-Iyz-Signature-V3 in timely manner.

Validation of Direct Format

SECRET KEY, iyziEventType, paymentId, paymentConversationId, status should be created with the given order below. This string should be encrypted with HMACSHA256 and the result should be encoded with HEX. Final value should should be equal to X-IYZ-SIGNATURE-V3 in the header.

Hashing Sample for Direct Format

// Create the key for HMAC
const key = secretKey + iyziEventType + paymentId + paymentConversationId + status;

// Generate HMAC SHA256 signature
const hmac256 = crypto.createHmac('sha256', secretKey)
                       .update(key)
                       .digest('hex');

Order	Parameter	Description
1	secretKey	Merchant's secret key
2	iyziEventType	Shows the request type. Values: PAYMENT_API, API_AUTH, THREE_DS_AUTH, THREE_DS_CALLBACK, BKM_AUTH, BALANCE, CONTACTLESS_AUTH, CONTACTLESS_REFUND,
3	paymentId	Unique iyzico reference code of realted payment
4	paymentConversationId	Merchant's reference id for the related payment.
5	status	Payment status. Values: FAILURE, SUCCESS, INIT_THREEDS, CALLBACK_THREEDS, BKM_POS_SELECTED, INIT_APM, INIT_CONTACTLESS

Validation of HPP Format

SECRET KEY, iyziEventType, iyziPaymentId, token, paymentConversationId, status should be created with the given order below. This string should be encrypted with HMACSHA256 and the result should be encoded with HEX. Final value should should be equal to X-IYZ-SIGNATURE-V3 in the header.

Hashing Sample for HPP Format

// Create the key for HMAC
const key = secretKey + iyziEventType + iyziPaymentId + token + paymentConversationId + status;

// Generate HMAC SHA256 signature
const hmac256 = crypto.createHmac('sha256', secretKey)
                       .update(key)
                       .digest('hex');

Order	Parameter	Description
1	secretKey	Merchant's secret key.
2	iyziEventType	Shows the request type. Values: CHECKOUT_FORM_AUTH, BANK_TRANSFER_AUTH, BKM_AUTH, BALANCE, CONTACTLESS_AUTH, CONTACTLESS_REFUND, CREDIT_PAYMENT_AUTH, CREDIT_PAYMENT_PENDING,CREDIT_PAYMENT_INIT, PWI_TKN_FUND, PWI_TKN_AUTH, PWI_TKN_THREEDS_AUTH
3	iyziPaymentId	Relevant paymentId which belongs to the payment.
4	token	The token generated for the related payment.
5	paymentConversationId	Merchant's reference id for the related payment.
6	status	Payment status. Values: FAILURE, SUCCESS, INIT_THREEDS, CALLBACK_THREEDS, BKM_POS_SELECTED, INIT_APM, INIT_BANK_TRANSFER, INIT_CREDIT, PENDING_CREDIT, INIT_CONTACTLESS

Validation of Subscription Format

The X-IYZ-SIGNATURE-V3 value sent in the header can be used to validate that the request originated from iyzico, and this value can only be decrypted with your SECRET KEY.

The SECRET KEY, merchantId, eventType, subscriptionReferenceCode, orderReferenceCode, and customerReferenceCode must be concatenated in the exact order shown below. This string is then hashed with HMAC-SHA256, and the result is HEX-encoded. The final value must match the X-IYZ-SIGNATURE-V3 in the header.

Hashing Sample

// A Key (message) is generated for the HMAC
const key = merchantId 
          + secretKey 
          + eventType 
          + subscriptionReferenceCode 
          + orderReferenceCode 
          + customerReferenceCode;

// The signature is generated with HMAC SHA256 (in hex format)
const hmac256 = crypto.createHmac('sha256', secretKey)
                      .update(key)
                      .digest('hex');

PHP

<?php

$merchantId = "merchantId";
$secretKey  = "secretKey";

$eventType = "eventType_from_webhook_payload";
$subscriptionReferenceCode = "subscriptionReferenceCode_from_webhook_payload";
$orderReferenceCode        = "orderReferenceCode_from_webhook_payload";
$customerReferenceCode     = "customerReferenceCode_from_webhook_payload";

// message = merchantId + secretKey + eventType + subReferenceCode + orderReferenceCode + customerReferenceCode
$message = $merchantId
    . $secretKey
    . $eventType
    . $subscriptionReferenceCode
    . $orderReferenceCode
    . $customerReferenceCode;

// HMAC-SHA256 raw → hex
$hmac256Signature = bin2hex(hash_hmac('sha256', $message, $secretKey, true));

$signature_v3 = "signature_v3_from_webhook_header";

if ($hmac256Signature == $signature_v3) {
    echo "Signature verification successful.";
} else {
    echo "Signature verification failed.";
}

?>

Java

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;

public class WebhookSignatureCheck {
    public static void main(String[] args) throws Exception {
        String merchantId = "merchantId";
        String secretKey  = "secretKey";

        String eventType = "eventType_from_webhook_payload";
        String subscriptionReferenceCode = "subscriptionReferenceCode_from_webhook_payload";
        String orderReferenceCode        = "orderReferenceCode_from_webhook_payload";
        String customerReferenceCode     = "customerReferenceCode_from_webhook_payload";

        // message = merchantId + secretKey + eventType + subscriptionReferenceCode + orderReferenceCode + customerReferenceCode
        String message = merchantId
                + secretKey
                + eventType
                + subscriptionReferenceCode
                + orderReferenceCode
                + customerReferenceCode;

        // HMAC-SHA256 raw → hex
        Mac sha256_HMAC = Mac.getInstance("HmacSHA256");
        SecretKeySpec secret_key = new SecretKeySpec(secretKey.getBytes(StandardCharsets.UTF_8), "HmacSHA256");
        sha256_HMAC.init(secret_key);

        byte[] hashBytes = sha256_HMAC.doFinal(message.getBytes(StandardCharsets.UTF_8));
        StringBuilder sb = new StringBuilder();
        for (byte b : hashBytes) {
            sb.append(String.format("%02x", b));
        }
        String hmac256Signature = sb.toString();

        String signature_v3 = "signature_v3_from_webhook_header";

        if (hmac256Signature.equals(signature_v3)) {
            System.out.println("Signature verification successful.");
        } else {
            System.out.println("Signature verification failed.");
        }
    }
}

Node.Js

const crypto = require("crypto");

const merchantId = "merchantId";
const secretKey  = "secretKey";

const eventType = "eventType_from_webhook_payload";
const subscriptionReferenceCode = "subscriptionReferenceCode_from_webhook_payload";
const orderReferenceCode        = "orderReferenceCode_from_webhook_payload";
const customerReferenceCode     = "customerReferenceCode_from_webhook_payload";

// message = merchantId + secretKey + eventType + subscriptionReferenceCode + orderReferenceCode + customerReferenceCode
const message = merchantId
              + secretKey
              + eventType
              + subscriptionReferenceCode
              + orderReferenceCode
              + customerReferenceCode;

// HMAC-SHA256 raw → hex
const hmac256Signature = crypto.createHmac("sha256", secretKey)
                               .update(message)
                               .digest("hex");

const signature_v3 = "signature_v3_from_webhook_header";

if (hmac256Signature === signature_v3) {
  console.log("Signature verification successful.");
} else {
  console.log("Signature verification failed.");
}