I'm working with PipeDrive API and I've started to use their webhooks. 
The problem is that it cause loops. 
Simple example:
There is a model Deal which has two methods - Deal.sync(), Deal.backsync()
Deal.sync() sends updated or created Deal object to the PipeDrive
Deal.backsync() fetches  Deal object from the PipeDrive
But the problem is that when I call sync, the Deal object is sent to the PipeDrive which invokes webhook so my server receives this webhook and automatically invokes Deal.backsync() etc.
I have some ideas but maybe there is some elegant way I don't know. Ideally, for example sync would send some uuid which would be sent in webhook so I know it was caused by sync.
Do you know how to make this work?
