Apple iCloud and CalDAV

What’s available

CalDAV sync and CalDAV in AI connectors are available. Alvin and external MCP assistants such as ChatGPT and Claude can read events and availability, create, update or delete standalone events without guests, and change, move or delete single occurrences of your own series. You can connect a CalDAV account directly in the guided setup when you add an assistant. Available operations depend on the CalDAV service, calendar permissions and your assistant’s access.

Connect your account

Choose the provider preset in Ridian, then enter the username and provider-required password. iCloud requires an app-specific password. Enter it only in the connection form. For a custom server or Nextcloud, workspace enablement may be required; the plan must allow CalDAV.

Use an existing test calendar for verification. Calendar creation itself remains at the provider. A preset for GMX, WEB.DE, mailbox.org, Infomaniak, Posteo, STRATO or Nextcloud does not establish that every offering supports every interactive operation.

Supported interactive operations

• Read events and existing recurring occurrences in a bounded window.
• Find free times; free and cancelled events do not block a slot.
• Create, modify and delete supported standalone events without guests.
• Change, move or delete one occurrence of your own series without guests; all other occurrences stay unchanged.
• Rename an entire series or change its description or location.
• Retry the same creation request without creating a second event.

Alvin uses your saved personal default timezone when it has permission to read it and you have not specified another zone. Set it in Settings. Tell external MCP assistants your IANA zone, for example Europe/Berlin. If the calendar does not expose its zone, a live query requires this explicitly. All-day dates and daylight-saving transitions must not be guessed.

Write protection

Invitations, series with organizer/attendee data and sync-managed copies are protected from these writes. Updates and deletes require a strong ETag; a concurrent change produces a conflict rather than overwriting the other edit. Re-read and inspect the current event before deciding what to do next.

CalDAV accounts provide calendar functions here. Create series, change their schedule and delete entire series in your calendar app. Invitation responses, calendar creation, contacts (CardDAV), tasks, outgoing email and rooms are outside the CalDAV AI scope. Google and Microsoft have their own bounded feature scope; single occurrences of their series work the same way. An ICS feed is not a CalDAV AI calendar. Use reconnect to replace an expired app password on the existing account.

A protected event in a writable calendar

A writable calendar can contain protected series or invitations. “Event cannot be edited” therefore does not mean “calendar is read-only”. Use your calendar app for series with guests and for moving one occurrence of an all-day series. If write permission is missing, check the assistant’s access. If the current version cannot be verified, read the event again.

To test editing, create a new standalone event yourself without recurrence, guests or conference data. Ask Alvin to move that exact event and review the preview. Responding to invitations is outside the CalDAV scope.