You can use a Zapier Action to link a contact to a property in SweepBright. In order to do this, choose the Link Contact to Property Action Event in the latest SweepBright for Zapier app:

Once you have selected your account as usual, you will see two ID fields to link a contact to a property in SweepBright. When you use the Create Property Zapier Action or the Find or Create Contact Zapier Action, you will get these ID's.

At the moment, this only works for Sellers.