When to use IPN and when WebHooks in PayPal as a notification mechanism?

Question

I'm looking at the documentation of WebHooks and IPN and I wonder: which one should I use my store where I don't need really real-time notifications? Even 1 hour delay will do. How do WebHooks and IPN differ for this matter?

Teetotal

Answer 1

IPN is the classical way of notifying merchants of events such as payments or subscriptions. It's coupled with the deprecated classic API. It might take a minute for events to reach the merchant.

Webhooks is the new REST API way where the event is sent almost instantly to the merchant.

It's better to implement Webhooks because it's the new way and IPN might be disposed of in the future.

Funiculate

webhooks have a couple of not so minor drawbacks. First, if you send a payouts with hundreds of payments the webhook will be notified hundreds of times. Sort of auto inflicted DDOS attack. Second events are not fired if you don't use the API. That is, if you make a simple payment from the PayPal webapp, the webhook won't be notified. This is also totally undocumented. – Babism

When designing such a system, it's best to make the Webhook receiver be behind a queue manager (such as RabbitMQ or other redis-supported queue workers) – Funiculate

@Babism Could you please elaborate on "the webhook won't be notified"? Do you mean when you send payments manually the webhook won't be triggered? Isn't this neglectable if you integrate the PayPal Checkout properly into your service? – Diecious

Answer 2

This is the entry point for PayPal's notification docs describing Webhooks, IPN and PDT: https://developer.paypal.com/docs/notifications/

I can't offer definitive differences but some sources say that Webhooks are faster on the first message than IPN. Webhooks are indeed more recently implemented. From my experience, IPN messages are complex and not straightforward at all. Webhook messages on first sight looked more straightforward.

Based on your description I don't think there're huge differences. I'd prioritize the approach with more existing libraries (if any) for your stack.

Sande

I am using Paypal Subscription API, which documented here https://developer.paypal.com/docs/api/subscriptions/v1/, I am using Paypal Webhook for callback/notification, but if a Payment of Subscription failed, Webhook didn't notified, But Paypal IPN have this feature that it notified me about skipped/failed payments. So I am thinking to use both Webhook and IPN, But I feared that Paypal deprecated many things, and may be IPN is the next one, So there is any possibility that Paypal will deprecate IPN? – Induct

Answer 3

Webhooks are HTTP callbacks that receive notification messages for events. Documentation : https://developer.paypal.com/docs/integration/direct/webhooks/

IPN Instant Payment Notification is a message service that automatically notifies merchants of events related to PayPal transactions.

Documentation : https://developer.paypal.com/docs/classic/products/instant-payment-notification/

Posh

And "how do webhooks and IPN differ" for the OPs purpose? – Worthen

In my opinion, webhooks would be cleaner. It also retries on failure and quicker than IPN as IPN takes around a minute. "If that application is unavailable or takes too long to respond, PayPal will cancel the request and retry 25 times over the course of 3 days." – Posh