Can I create Billing agreements for $0

[GuestPost]

Hi All,

I have a marketplace and I want to onboard my sellers by setting up a billing agreement with them.

Can I create Billing agreements for $0 and then whenever they make a sale on my portal. I will charge them fee afterwards. Is that possible? 

I had a look into this API here: https://developer.paypal.com/docs/api/payments.billing-agreements/v1/

But not clear enough hence asking a question.