Google Calendar two-way sync

Booklink uses Google Calendar's push notification API to keep bookings and personal events in sync in real time. Once a user connects their Google account through OAuth, Booklink writes every confirmed booking as a calendar event on their primary Google Calendar, including the client's name, the service, and the booked duration. In the opposite direction, Booklink subscribes to changes on that calendar, so when the user adds a personal event (a school run, a doctor's visit, a holiday), that time slot is marked as busy on their public Booklink booking page. Clients cannot book over those times. Each team member on a Pro plan connects their own Google Calendar, so personal events only block that individual's availability, not the whole team's. Services can also generate a Google Meet link for every confirmed booking: the link is included in the client's confirmation email, the calendar invite, and their manage-booking page, which makes Booklink a natural fit for tutors, consultants, and coaches who work online. Providers can additionally opt in to grey out fully booked days on the public booking page based on Google Calendar busy times. Booklink only reads free/busy information from events it did not create - event titles, descriptions, and attendees of personal events are never stored or displayed.