Attendarra turns any WordPress post type into a seat-limited event registration form. Attendees fill out a short form, are automatically confirmed or placed on a waitlist depending on seat availability, and — if a Calendly link is configured — are handed straight to a Calendly scheduler to pick their time slot.

Registration and waitlisting

Seat-limited registration with automatic waitlisting once a seminar is full.
Automatic waitlist promotion: when a confirmed registrant cancels or is removed, the oldest fitting waitlisted registration is promoted automatically (seat, Calendly link, and email notification included), oldest first.
Optional “bring a guest” field with a configurable max seats per registration.
Configurable extra fields per seminar (e.g. “Company”, “Job title”) that appear as extra text inputs on the form and are stored per registration.
Built-in honeypot spam protection — no CAPTCHA, no extra dependency, invisible to real visitors.

Scheduling and reminders

Built-in Calendly integration: embed a public scheduling link, or generate single-use scheduling links via the Calendly API. Entirely optional — leave it blank and the form works as a plain RSVP.
Optional seminar date/time field. When set, it powers automatic reminder emails (configurable hours before the seminar) and a downloadable .ics calendar file offered to confirmed registrants.

Self-service and admin tools

[atdra_seminar_my_registrations] shortcode lets attendees look up their own registrations by email and cancel them without contacting an admin (cancelling frees the seat and triggers waitlist promotion).
Admin dashboard for registrations (update status, bulk remove, one-click CSV export) and a separate participants archive that keeps contact history even after a registration is removed, with its own CSV export.
A Gutenberg block (“Seminar Registration Form”) lets editors pick a seminar from a dropdown instead of typing the shortcode by hand.
Configurable confirmation, waitlist, and consent messages per seminar.
Email notifications to the admin and the registrant on every submission, promotion, and reminder.

Design

Choose from 5 built-in color palettes (violet, blue, green, amber, slate), or enter your own custom hex colors — set a site-wide default and override it per seminar.

Privacy

Built-in support for the WordPress personal data export and erasure tools.
Data (custom database tables, seminars, and settings) is kept by default when the plugin is deleted; a setting lets you opt into full cleanup on uninstall instead.

Calendly modes:

Public link mode — embeds your existing Calendly link after a confirmed registration.
Single-use mode — requires a Calendly Personal Access Token and an Event Type URI, and creates a fresh one-time scheduling link per registrant.

External services

This plugin can optionally connect to Calendly, a third-party scheduling service, to let confirmed registrants pick a time slot. Calendly is only contacted if a site owner configures a Calendly link on a seminar; if left blank, the plugin works as a standalone registration form with no external connections at all.

Calendly scheduling widget (public link mode): if a seminar has a public Calendly link configured, the plugin loads Calendly’s widget script (https://assets.calendly.com/assets/external/widget.js) in the confirmed registrant’s browser to display the embedded scheduler. The registrant’s name and email, as entered on the registration form, are sent to Calendly to pre-fill the scheduling widget.
Calendly’s terms of service: https://calendly.com/legal/customer-terms-conditions
Calendly’s privacy policy: https://calendly.com/legal/privacy-notice
Calendly Scheduling Links API (single-use mode, opt-in): if a site owner enters their own Calendly Personal Access Token and Event Type URI to enable single-use scheduling links, the plugin’s server sends that Event Type URI to Calendly’s API (https://api.calendly.com/scheduling_links), authenticated with the site owner’s token, to generate a one-time booking link for each confirmed registrant. This request happens only when single-use mode is enabled; no registrant personal data is included in this particular request.
Calendly’s terms of service: https://calendly.com/legal/customer-terms-conditions
Calendly’s privacy policy: https://calendly.com/legal/privacy-notice