Automate event ticketing and waitlists with multi-tier PDFs and PDF Generator API

Automate event registration with capacity management, a waitlist, and multi-tier PDF ticket generation using PDF Generator API. When attendees register, the workflow checks available spots, routes by tier (General / VIP / Backstage), generates a PDF ticket with a QR code, emails it, logs to Google Sheets, and notifies via Slack. Full event? Attendees are waitlisted and automatically promoted when a cancellation opens a spot.

Who is this for

Event organizers and developers who need automated ticketing with capacity control and waitlist logic — without a custom backend.

How it works

Flow A — Registration (form trigger): Attendee submits the form → workflow reads Sheets to check capacity → if spots available, a Switch routes by tier, each adding tier-specific perks → PDF Generator API creates a personalized ticket with QR code → confirmation email via Gmail → logged to Sheets → Slack notification. If full → added to waitlist tab → waitlist email sent.

Flow B — Cancellation & promotion (webhook trigger): Webhook receives a ticket ID → validates and removes from Sheets → checks waitlist → if someone is waiting, the first person is auto-promoted: new PDF generated, emailed, logged, waitlist entry removed, organizer notified. If waitlist is empty → cancellation-only Slack alert.

Set up

PDF Generator API — Create 3 templates (General, VIP, Backstage) using variables: ticket_id, attendee_name, event_name, venue, event_date, seat_number, ticket_tier, issued_date. Add a QR Code component bound to ticket_id. Google Sheets — One spreadsheet, two tabs: Registrations and Waitlist. Column details are in the workflow's sticky notes. Code nodes — Replace placeholder template IDs and set MAX_CAPACITY in the "Check Capacity & Prepare Data" and "Promote from Waitlist" nodes. Credentials — Connect PDF Generator API, Gmail, Google Sheets, and Slack in their respective nodes.

Requirements

PDF Generator API account (free trial available) Gmail (OAuth), Google Sheets (OAuth) Slack workspace (optional — remove the 3 Slack nodes if not needed)

How to customize

Tiers** — Add/rename tiers in the form, update the Switch and both Code nodes accordingly. Perks** — Edit the Set nodes to change tier-specific perks shown in emails. PDF output** — Switch from URL to File output to attach PDFs directly to emails. Payment** — Insert a Stripe node before capacity check for paid tickets.