Running Google Apps Script by Event Notification from Google Calendar

Gists Overview This is a simple method running Google Apps Script by the event notification from Google Calendar. Description There are several event triggers in Google Apps Script. Ref1, Ref2 There is an event trigger for Google Calendar. The official document says An installable calendar event trigger runs when a user's calendar events are updated—created, edited, or deleted.. Ref3 If I want to use the trigger when the event in the calendar is starts and finished, it is required to use Calendar API by preparing the URL for receiving from Google.