title: Google Calendar API v3 adding a duplicate event to attendees' personal calendars
body: <p>Recently migrated from v2 to v3. Previously (with v2), when events were synced to Google, an event was simply added to a non-personal calendar. The synced event also included the attendees' email address. With the newer version (v3), we've noticed Google creates a duplicate event on the attendees’ personal calendars using the same process as before. This creates a completely different event with its own eventId, unrelated to the one we created via the API. </p>
  
  <p>We came across this article while doing some research: <a href="http://bittwiddlers.org/index.php/2012/10/google-calendar-api-v3-undocumentation/#awp::index.php/2012/10/google-calendar-api-v3-undocumentation/" rel="nofollow">http://bittwiddlers.org/index.php/2012/10/google-calendar-api-v3-undocumentation/#awp::index.php/2012/10/google-calendar-api-v3-undocumentation/</a>. Here's a snippet:</p>
  
  <blockquote>
    <p><strong>Adding email addresses as attendees copies the event to the attendees’ personal calendars. This creates a completely different event with its own eventId, unrelated to the one you created via the API. As far as I can tell, there is no programmatic way to determine if this duplicated event originated from the event you created via the API.</strong></p>
  </blockquote>
  
  <p>Does anyone have any ideas as to why this behaviour is occurring? And how it can be prevented. Spent some time digging through the list of questions on calendar API, but didn't find anything useful. If there are similar threads, please feel free to point 'em out. Thanks.</p>