Limits when accessing Google APIs using Service Account vs OAuth

Question

My current application access one of the Google APIs using "3-legs" OAuth 2.0. User authorizes the app on Google consent screen, then the app requests API on behalf of the user and shows him some fancy data loaded from API. Everyday my application loads and transforms data from this API, so when the user comes next time, he sees the most relevant and actual data.

Everything works fine on the start, but as time goes, I faced two problems: 1. Query limits. 2. Token lifetime.

My question is dedicated to the second one, that I refer as "token lifetime". After some amount of time, the access token expires, and when user comes back to the app, our app obliged to send him to consent screen again. Moreover, all the time while access token has been in expired state, my app cannot load relevant data for user.

How can I solve this problem? How to continue lifetime of access/refresh tokens? Would Service account help? Would Service account work for Google Search Console API for every user, or should the user be a G Suite user inside my domain or what? These questions are completely unclear from the official documentation here and from the Search Console API documentation .

If you have past experience with Google's APIs, please help me! Thank you

Answer 1

When you use OAuth with user-consent, you do not need to prompt the user for consent repeatedly.

[a] If your usecase is entirely online and you want to be able to request a token each time the user visits your app, use the Google Sign In library or see this documentation for client-side apps .

[b] If your usecase is that you want to be able to obtain access tokens even when the user is not present, then you need to request an authorization code and store your refresh token. Your refresh tokens are longer-lived tokens and can be exchanged periodically for access tokens .