Unofficial API's Spotify Login and Subscription checking, no API Key required.
This API is now deprecated.
This Class requires Curl extension.
With this Class, you could check if a given account works, and get its subscription.
For Example:
//include the class
include('class.spotify.php');
$spotify = new spotify();
echo $spotify->check("yourUsername", "yourPassword");
If you gave invalid credentials you'll get an output like: {"status":"fail","error":"errorInvalidCredentials"}
If you gave valid credentials you'll get an output like this: {"status":"success","error":"none","subscription":"PREMIUM"}
In this case, the user has a PREMIUM subscription, if the users hasn't a premium subscription, you'll get an output like this: {"status":"success","error":"none","subscription":"FREE"}