For follower count in helix you just use the Get Users Follows endpoint and set the
to_id to the channel you want to see the follower count of.
As for subscriptions in Helix, both Get Broadcaster Subscriptions and Get Broadcaster’s Subscribers are worded VERY badly. Both endpoints are exactly the same, they return a list of all users subscribed TO the broadcaster (which is the use who’s token with the
channel:read:subscriptions scope you’re using). All the latter endpoint does is then filter that list with the
user_id param so you can check if users are subbed without using pagination to go through the whole results.
As for getting total number of subscribers, use the first endpoint (so the same as the 2nd endpoint but without using the
user_id param) and page through all the results.
Having a ‘total’ field, as well as the fields for additional data from an undocumented endpoint that shows a breakdown of subs at each tier and points to next emote unlock, is something that several of us have asked for since these endpoints went live, especially a
total field at the very least. Sadly there has been no word of changes yet, and the docs remain in a confusing state.