Receiving objects in Speckle Server

Hello,
I was looking around speckle server code for receiving a latest commit in an application, but I couldn’t find where in the server code it gets triggered to fetch data from postgresql.
Actually what I am trying to do, is use another Api to receive an object and send that information to Speckle client. Can you help me to point in the code how the receiving option works on server code.
Thank you!