Filtering out my Steam library

[cprn]

Hi, I'm new to this. Can I somehow filter out the games I already own on Steam?

The best option I found so far is to go through my Heroic library game by game, and put all games I own on Steam in some category, that I could filter out later on. I don't want to do it manually, though.

Is there an API that'd let me do it?

If not, is there a way to copy the game title from Heroic library or details view?

Because as a last resort, I could use dotools to automate mouse movements to read a game title, then compare with my Steam library, then right click, add to category, etc.