n8n Webhook for Google Calendar RSVP: Gmail & Sheets

Turn Google Calendar RSVP emails into real updates—automatically

This n8n workflow powers a Webhook for Google Calendar RSVP, letting attendees confirm, reschedule, or cancel a meeting using email links. It then sends matching Gmail notifications, logs the action to Google Sheets, and returns a branded HTML response page to the attendee.

What this workflow does

• Receives an RSVP request via a webhook containing: action (confirm/reschedule/cancel), attendee email, and eventId (plus optional newDateTime/meetingDate for rescheduling).
• Validates inputs and returns an HTML error page if required fields are missing or the action is invalid.
• Fetches the Google Calendar event by eventId; if the event no longer exists, it returns an HTML “not found” page.
• Creates meeting context (attendee name, title, start/end time, and meeting link) and routes logic based on the selected action.
• Confirm: updates the Google Calendar event color to mark it as confirmed and sends a confirmation email via Gmail.
• Reschedule: parses the requested new time, updates the event’s start/end, and sends a reschedule email via Gmail (or returns an HTML error if the time can’t be parsed).
• Cancel: deletes the Google Calendar event (notifying guests), sends a cancellation email via Gmail, appends the action to Google Sheets, and returns a branded HTML success page.

Use cases

• Event teams that want RSVP links to immediately update Google Calendar and notify attendees.
• SaaS operators scheduling customer onboarding calls who need reliable confirm/reschedule/cancel flows.
• Automation engineers building a complete Google Calendar RSVP pipeline with audit logging in Google Sheets.

Technical details

• Webhook entry point for RSVP actions.
• Google Calendar OAuth2 for event retrieval and updates (confirm/reschedule/delete).
• Gmail node to send confirmation, reschedule, and cancellation emails.
• Google Sheets credentials to append RSVP actions.
• Control flow uses nodes including if, switch, set, and code, plus HTML responses.

Setup tip: Connect Google Calendar OAuth2 credentials, Gmail credentials, and Google Sheets credentials to the respective nodes, then configure the workflow in Workflow Config.