Cal.com No-Show Webhook to HighLevel CRM + WhatsApp + Sheets

Turn Cal.com no-shows into fast reschedules—automatically

This n8n workflow listens for Cal.com no-show webhooks, updates the matching contact in HighLevel (GoHighLevel), logs each no-show in Google Sheets, and—only when appropriate—sends the attendee a WhatsApp reschedule link.

What this workflow does

• Receives Cal.com no-show events via a POST webhook (configured at the workflow’s /cal-noshow path).
• Fetches full booking details from the Cal.com API, extracting attendee name, email, phone, booking UID, and the time slot.
• Prevents duplicate processing by checking the Google Sheets NoShowLog tab for an existing bookingUid.
• Updates HighLevel contacts by looking up the attendee in HighLevel using their email. If found, it updates custom fields to set a no_show flag and increments a no_show_count.
• Logs the no-show event to Google Sheets (timestamp, slot details, booking UID, contact details, and no-show count).
• Sends a WhatsApp reschedule message when the attendee’s no_show_count is below 3, including a Cal.com reschedule link containing the booking UID.

Use cases

• Service businesses using Cal.com who want an automatic no-show follow-up without manual outreach.
• Teams managing leads in HighLevel who need a reliable record of no-shows for reporting and outreach logic.
• SaaS operators who want database-style deduplication using Google Sheets to avoid repeated webhook side effects.

Technical details

• Cal.com webhook intake (webhook node at /cal-noshow)
• Cal.com API fetch for booking details
• Google Sheets OAuth2 integration with a NoShowLog tab and bookingUid column
• HighLevel (GoHighLevel) OAuth2 contact lookup and custom field updates
• WhatsApp messaging with a reschedule link (threshold: no_show_count < 3)
• Workflow logic using nodes such as if, set, and no op