YouTube API. Check for user was subscribed

Question

What the best way to determine when authorized user was subscribed to YouTube channel by channel's id through YouTube Data API? I assuming it is possible somehow by "Subscriptions.list" API method. But how exactly?

Answer 1

If you know the channelId of the channel you want to check the user is subscribed to, you can perform an HTTP GET request on the subscriptions/list endpoint with the parameters part set to id and mine set to true:

HTTP GET https://www.googleapis.com/youtube/v3/subscriptions?part=id&mine=true&key={YOUR_API_KEY}

You could also pass in snippet for part to get information about each channel the user is subscribed to. With this approach, you would have to iterate through every channel that authenticated user is subscribed to, and check if your channel exists in that list.

You could also send an authenticated POST request to the subscriptions/insert endpoint with the channelId of the channel you want to subscribe to with the part param snippet, and if the user is already subscribed to that channel, the request will return a 400 error with the message subscriptionDuplicate.

HTTP POST https://www.googleapis.com/youtube/v3/subscriptions?part=snippet&key={YOUR_API_KEY}