There is an endpoint on the private API for the subscriber score which is what is used on the dashboard.
https://api.twitch.tv/api/channels/:channel_name/subscriber_count
Where channel_name is the name of a channel. (Not the ID) You authorize normally in the headers:
Authorization: 'OAuth ' + token
Or as part of the query string: ?oauth_token=...
This is what the data might look like for an affiliate:
{
"count": 5,
"score": 5,
"count_breakdown": [
{
"plan": "1000",
"count": 5
},
{
"plan": "2000",
"count": 0
},
{
"plan": "3000",
"count": 0
}
],
"score_breakdown": [
{
"plan": "1000",
"score": 5
},
{
"plan": "2000",
"score": 0
},
{
"plan": "3000",
"score": 0
}
],
"next_level": null
}
And this is what the data might look like for a partner:
{
"count": 154,
"score": 172,
"count_breakdown": [
{
"plan": "1000",
"count": 144
},
{
"plan": "2000",
"count": 8
},
{
"plan": "3000",
"count": 2
}
],
"score_breakdown": [
{
"plan": "1000",
"score": 144
},
{
"plan": "2000",
"score": 16
},
{
"plan": "3000",
"score": 12
}
],
"next_level": {
"minimum_score": 400,
"emoticon_limit": 18
}
}