Your calendars, connected to everything
Open protocols wherever possible, official APIs everywhere else. No scraping, no shortcuts, no surprise permissions.
Calendar providers
The calendars CalSync reads from and writes to.
Google Calendar
OAuth 2.0 with push notifications. Personal accounts and Google Workspace, across as many organisations as you like.
Microsoft Outlook
Microsoft Graph for Outlook.com and Microsoft 365, including shared and secondary calendars.
Apple iCloud
Standards-based CalDAV using an app-specific password you generate and can revoke.
Conferencing
Meeting links generated when someone books.
Google Meet
A fresh Meet link on every booking, attached to the calendar event.
Zoom
Attach your Zoom room to any booking link, or generate one per meeting.
Microsoft Teams
Teams meetings created alongside the calendar event for Outlook accounts.
Automation & AI
Push CalSync events into the rest of your stack.
Zapier
Trigger 9,000+ apps on a new booking, a cancellation or a failing sync.
MCP server
Give an AI assistant read access to your availability and let it book on your behalf, under rules you set.
Webhooks
Signed HTTPS callbacks for every booking and sync event, for anything custom.
Missing something you rely on?
The provider layer is a single interface with four methods. Adding a new calendar backend is a few hundred lines — contributions very welcome.
Read the contributor guide