Google / Youtube Oauth2.0

[lmquang]

Google / YouTube Authentication using a Brand Account

Below describes the only way I was able to get (programmatic) access to the YouTube Analytics API on behalf of our Brand Account.
Google documentation is convoluted, to say the least, so if you know a more straightforward way, please do share.

Getting a Client ID and Refresh Token

1. Create a Project in the Developers Console - https://console.developers.google.com/
2. Go to the Library tab and enable desired APIs (e.g. YouTube Analytics)
3. Go to OAuth consent screen and make project external. Select Test mode
4. Go to Credentials and create OAtuh Client ID credential: Application type = web; redirect uri = https://developers.google.com/oauthplayground
5. Go to https://developers.google.com/oauthplayground
6. Select gear icon -> Access type = Offline, Force prompt = Select Account Screen, Use your own OAuth credentials = checked --> enter client id and client secret from step 4
7. Click Select & authorize API's and select the desired APIs (e.g. https://www.googleapis.com/auth/youtube.readonly , https://www.googleapis.com/auth/youtubepartner , https://www.googleapis.com/auth/yt-analytics-monetary.readonly and https://www.googleapis.com/auth/yt-analytics.readonly
8. Click 'Authorize APIs'
9. In the consent screen, first select your Google account, then in the next screen select your brand account
10. Back in the OAuth Playground, you received an Authorization Code. Click Exchange authorization code for tokens
11. Copy the Refresh token
12. Go back to your project in the Developers Console and change the User type to internal by clicking the Make internal button
13. Download your Client ID json from the Developers Console: Credentials -> OAuth 2.0 Client IDs table -> Click the download icon next to your Client Id (in the far right of that row)

source: https://gist.github.com/veuncent/e0b831ab41d598961d2656c7fc5cc0f9