How to sync paypal payment state to my own database

[tomnotcat]

The first solution I can think up is use webhook notification,

But what does paypal do when webhook notification not send successfully.

for situations like:
My webhook notification process server crashed, or some network problems.

Does paypal will resend the same notification later?

If not so, how should I handler situations like these, actively use paypal API to query payment state or what.

[MTS_Andre]

Hi, that's correct, in case the webhook can't be delivered at the first attempt PayPal will retry for other 25 times so any issue occurring during the delivery should be covered.