In-house mediation is a model that allows you to build your own mediation stack and run the auction instead of through a mediation platform. This provides high customizability and control and is generally for publishers with well-resourced developer teams. Facebook demand is accessed through Audience Network’s Bidding Kit.
To get started with in-house mediation, talk to your Facebook sales representative about the approval process for your business.
For in-house, an auction can be run on the server side or client side (the end user).