Near-real-time calendar sync comes from a durable baseline, provider-native delta state, expiring notification subscriptions, idempotent application, and periodic reconciliation.
Discover the calendars the user authorizes, choose the date horizon, page all events in that scope, and record the provider's final sync token or delta link only after the local view is committed.
Google watch notifications indicate a collection changed but contain no event body. Run incremental events.list with the stored sync token, replace it with nextSyncToken, and perform a new full sync when Google returns 410 Gone.
Maintain delta state for the selected calendar view and follow opaque next and delta links. Validate and renew change-notification subscriptions, then reconcile from delta rather than treating each notification as the complete change.
Notification channels expire and renewal can overlap. Deduplicate changes by provider identity and version, serialize cursor advancement per collection, measure lag, and schedule a lower-frequency reconciliation pass.
No. Providers normally notify quickly, but delivery and processing can lag. Publish and monitor a realistic sync-lag objective with reconciliation for missed signals.
No. Their cursor formats and scopes differ. DewEngine can expose one normalized sync state while each connector owns its provider-specific token or link.
Not as released connectors. Google Calendar has one feature-flagged development method, calendar.event.create, plus list/get for DewEngine-confirmed creates and the resulting canonical creation event. Provider calendar reads and sync, update/delete, availability, recurrence, watches, and Microsoft Graph Calendar remain planned. The implemented slice has only local fake-provider evidence, not real-account or production conformance.
DewEngine is in development. Real use cases decide what ships first.