Post-event thank-you emails and Slack recap for Eventbrite

Every morning at 8am local time, run a post-event follow-up routine for my Eventbrite events. The workflow has two jobs: send a personalized thank-you email to every attendee who actually checked in yesterday, and post a single recap of yesterday's events to a Slack channel.

Step 1: find yesterday's events. Use Eventbrite's List Events by Organization to fetch events for my organization and keep only the ones whose end.utc falls within the last 24 hours. Ignore events that are still upcoming or ended before yesterday.

Step 2: pull the roster for each event. For every event from step 1, call Eventbrite's List Attendees by Event and paginate through the full list. On each attendee, record the event name, the attendee's first name and email, the order status, and the checked_in boolean. Keep the full roster in memory so I can compute totals later; do not throw away no-shows or cancelled orders here, because I still want them in the Slack recap.

Step 3: draft and send the thank-you emails. For every attendee where checked_in is true and the order status is not cancelled or refunded, use Gmail's Send a Message action to send a personal thank-you email from my Gmail account. Personalize the greeting with the attendee's first name, name the specific event they attended in the subject line and first sentence, thank them warmly for coming, and include a short feedback ask. If I supply a feedback link, use that; otherwise ask them to simply reply with a sentence or two about their experience. Deduplicate by email address so a person who bought multiple tickets to the same event only gets one message. Skip any attendee with a missing or clearly invalid email address.

Step 4: post the Slack recap. After the emails are sent, use Slack Bot's Send a Message action to post one message to my chosen Slack channel. The recap should be a single, well-formatted message that lists each event that ran yesterday, and for each one shows: attendees checked in vs. total registered, the no-show rate as a percentage, and how many thank-you emails were sent. End with a one-line total across all events. If no events ended yesterday, post a short note saying so instead of a full recap.

Guardrails: never email attendees whose order was cancelled or refunded, never email no-shows, and count both categories only in the Slack recap. If Gmail rate limits or an individual send fails, continue with the rest of the attendees and note the failure count in the Slack recap. Never invent stats; every number in the recap must come from the attendee data returned by Eventbrite.