Merchants can set up a callbackUrl in their merchant requests, and upon processing payments, CashPay will send you notifications in JSON format with all required information about the transaction, such as the amount and status, when the payment status is changed to Waiting, Confirming, Paid, Failed, or Expired.

To receive webhook notifications, first, you should implement a standard HTTP POST (application/json) call over an HTTPS URL to a CGI script on your server. Insert your created endpoint address in the callbackUrl field of merchant requests. You will receive payment updates (statuses) to this URL address.

However, you will initially receive a callback with the “Confirming” status. You should wait for a second callback where the “status” value will be “Paid”. When we confirm the transaction, we are ready to manage all the risks concerning accepting real funds later. You should not be concerned about it.

Merchant’s callbackUrl must return an HTTP Response 200 with content: ok for CashPay API to confirm the callback as successful. The system will try to deliver a webhook notification up to 5 times or until a successful delivery occurs, whichever happens first. If the first attempt fails, the second one is triggered after approximately 1 minute. The third one is delayed for 3 more minutes, the fourth for 30 minutes, and the last one for 3 hours.

The payout webhook is similar to a merchant webhook exactly. But for withdrawals, you will receive different values of the “address” parameter in every callback.

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Validating Callbacks

Merchants must validate the signature of callbacks coming from CashPay using either their Webhook Secret Key if the webhook was set up in the dashboard, or an API Keyassociated with the account if webhook is from callbackUrl. also for payout webhooks you must validate the signature using your PAYOUT_API_KEY. CashPay uses your MERCHANT_API_KEY as the HMAC shared secret key to generate an HMAC(sha512) signature of the raw POST data. The HMAC signature is sent as an HTTP header called HMAC. The body of the request contains the callback data in JSON format, similar to the Payment Information API response body.

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Testing Webhook

For payment callback handling, you can use tools like requestcatcher.com to create a test callbackUrl and inspect the callback data sent from CashPay. Note that CashPay payment callbacks will not be sent to private networks (e.g., localhost).

For local debugging, you can use services like https://ngrok.io to expose your local server to the internet and receive webhook callbacks.

To utilize the payment webhook, please follow these steps:

  1. Create a web server and define an endpoint to handle POST requests.

    • Ensure that the firewall software on your server (e.g., Cloudflare) allows incoming requests from CashPay. You may need to whitelist CashPay’s IP addresses on your side. Please reach out to support@cashpay.space to obtain the list of IP addresses.

  2. Configure your server to receive POST requests at the specified endpoint URL.

    • The POST request body will contain the necessary parameters sent by CashPay in JSON format.

  3. Validate the HMAC signature of the request to ensure the authenticity of the callback.

    • Use your MERCHANT_API_KEY to calculate the HMAC signature and compare it with the received HMAC header.

  4. Process the callback data accordingly based on the status and other parameters provided.

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Sample Payment IPN data

In this section, we will provide examples of the data CashPay send to your system at various stages of the payment process.

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Example codes

Again, please note that these code snippets serve as examples and may require modifications based on your specific implementation and framework.

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Troubleshooting

Here are some common issues you might encounter when implementing webhooks and how to solve them:

If you’re still experiencing issues after trying these solutions, please contact our support team at support@cashpay.space for further assistance.

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