What are the ways to get twitch streaming on the site?

Question

Video broadcast

I guess that it is enough to insert a link into a frame, but I'm wondering how this is implemented from the point of view. player. Is there any way to find out that he started the game, except for asking him this link himself? It's not very clear from their API.
I think that for people with experience the answer to this is obvious, but I don’t know where to dig.