iCal sync
Keeping calendars in sync by sharing a standard .ics feed between tools — for example, importing Airbnb and Booking.com availability into one calendar. It's one-directional and updates on a delay, so it isn't a real-time API connection.
How it works in Recal
Recal imports OTA calendars by iCal, shows exactly what synced and when, and flags overlapping dates so an iCal lag doesn't become a double booking.