Here are the requests I’m using for testing:
curl -X GET 'https://api.twitch.tv/helix/streams?user_id=26735539' -H 'Authorization: Bearer REDACTED' -H 'Client-Id: REDACTED'
curl -H "Accept: application/vnd.twitchtv.v5+json" https://api.twitch.tv/kraken/streams/?channel=26735539 -H 'Client-Id: REDACTED'
Where the user ID corresponds to my channel that I’m using for testing (http://twitch.tv/abcric).