java – What are the steps to consume Real Time Streaming data API and do we always get a client library by their providers in order to consume it

I am having doubt most of the real time streaming API providers like twitter, YouTube etc. provide their client library as well to consume their streaming API. Is this the case with all streaming APIs.
I want to make a real time data pipeline by consuming real time streaming API and put data onto kafka topics. Suggestions for any free real time streaming API.