How to write a website that will display user statistics in Steam games?

Question

Steam

Good afternoon.
I play dota 2 from time to time. It became interesting how the sites dota2lounge.com, www.dotabuff.com interact with Steam and DotA itself.
Let's say you decide to write a site that displays user statistics in the game Dota 2. So where to dig? Which way to look?
I would be insanely happy with links to some tutorials (Google did not help. Google is very bad).

Answer 1

Most likely, each game server should provide an api with which you can receive certain data.
For example, use this library: https://github.com/kronusme/dota2-api