As more YouTube channels start using Google+ page identities, here are some best practices to ensure that your code can make authorized API calls to access the channel.
With Google+ page identities, there can be many channels associated with a single Google Account. For example, when a user Alice Smith signs into her Google Account, she may have her “Alice Smith” (personal) channel on that account, and potentially additional channels, linked to Google+ pages, on associated accounts. These associated accounts do not have a password by default; she gets access to them by signing into her personal account, and then using a switcher to go back and forth between them.
How does this channel selection work with APIs? With API access through web-based OAuth 2, the switcher comes automatically. The web flow will ask Alice which account she wants to use, after she signs into her “Alice Smith” account. The OAuth 2 tokens your application gets back work just as they do today.
The OAuth 2 web-based “Select an account” interface, allowing a user to grant access to their personal channel or any channels linked to Google+ pages that they manage.
If you’re not using web-based OAuth 2 (you are still relying on one of our deprecated authorization methods), or if you are an Android developer who is using OAuth 2 (there is currently no native Android account switcher), then the API will choose the “wrong” channel in some cases, or even no channel (e.g., if the personal account doesn’t have a channel). When this happens, the user has two options to specify the correct channel:
- Use the Advanced Account Settings tool to select which channel should be used. This is recommended when a user has one channel they want to use for all applications.
- Set up login credentials for each of their Google+ pages, and specify those credentials, not their normal Google Account credentials, for each application that needs access.
As a best practice, we recommend that you ensure users know of these options, so your application will access the correct channel. Even more importantly, we recommend that all applications provide visual feedback letting users know which channel is currently authorized. If you’re still using version 2 of the YouTube Data API, you can retrieve the profile of the special identifier default; this corresponds to the currently authorized channel’s profile. In the version 2 response, the channel’s display name is returned as an attribute of yt:username, and the profile image can be found by looking at media:thumbnail. If you’ve started using version 3, then the method to use is channels.list() with the part=snippet and mine=true parameters set. The version 3 response contains a channel’s display name in channel.snippet.title and profile image in channel.snippet.thumbnails.default.url.
To summarize, here are the high-level points to keep in mind:
- OAuth 2 will automatically display a “Select an account” web interface, allowing users with multiple channels associated with their account to choose which one they’re authorizing access to.
- ...this doesn’t apply to Android OAuth 2, yet.
- All developers are strongly encouraged to display visual feedback letting their users know which channel is currently authorized.
Cheers,—Jeff Posnick, YouTube API Team