Google Calendar "Calendar limits exceeded" 403 error, but "Queries per minute" are way under the limit

[davidp-ro]

Hello!

We're dealing with a weird situation where some Google Cal API requests respond with the 403 "Calendar limits exceeded", even though I look in the Console, we seem to be way under for "Queries per minute" (which I assume count "Queries per minute per user" as well?).

The setup is like this:

• We have two accounts (say worker1@our-domain.com and worker2@our-domain.com) that are signed in to our management platform (OAuth with all calendar scopes)
• We have client accounts (>20), that each share (w/ Edit events permissions) their calendars with either worker1@... or worker2@... in such a way that it's reasonably balanced)
• Both we and our clients use Google Workspace (so worker1@... and worker2@... are members of our workspace and let's say user1@client1.com, user2@client1.com, userx@clientx.com all are members of their own Workspace)

Every ~20 minutes we search for events with a custom criteria:

• we query for all events in the next 3 months, and cache results (so that if we're looking for events in a particular calendar we do not keep making requests)
• we search the cached events for that "custom" criteria
• if one is found it gets processed (modifying the title, moving the event, etc.)
  • these actions are run concurrently
  • the endpoint/API method that fails the most seems to be moving (calendar.events.move)
  • if the method fails with a 403 we wait a full minute before retrying, but it seems that this is not helping and that error is returned again.
• I should mention that at this time events are processed one by one! (initially, we were doing ~10 at once, but we have since [for the last 2 weeks or so] tried only to do them one at a time)

The bottom line is - where's the flaw and what is causing the API to trigger the rate limit when, if you look at the Queries per minute value for the entire project we're between 7-20 queries/min...

I know ideally each calendar used would be signed into our platform and thus we'd use their own account to make changes, but, that's not an option at this time.

Ideas/Opinions?

Thanks!

[davidp-ro]

It seems like this is the intended behaviour so I'll close this myself.

TLDR: When moving/creating/etc events, do not send notification emails as that will trigger the spam protection.