Tax question regarding hard money loan

[Jonathan Smith]

A friend and I both provided half of the capital for a hard money loan used to flip a house.  He is a real estate agent and got to list the property as part of the deal.  In addition to the interest income I received on my principal, my friend shared his commission from selling the property with me.  What is the correct way to classify this part of my income from the deal?  What paperwork/records do I need to keep for tax purposes, both for the loan and the shared commission?  Thanks in advance for any advise!