Write access (creating events)

On every plan, you can allow the assistant to create events per calendar. When connecting an assistant and under AI assistant → Edit sharing, open the sliders icon next to the access label on a selected calendar to set the detail level and both write permissions. New grants start with the maximum supported permissions; you can narrow them before confirming. Reconnecting never broadens existing grants.

The second permission additionally allows changing and deleting existing events and responding to invitations. It remains separate because changing an existing event has different consequences from creating a new one.

What the assistant may do

With the first toggle:

• Create events — “Book me a meeting with XY on Tuesday 10–11am.”
• Change or delete its own events — the ones it created itself.

With the second toggle, additionally:

• Change and delete existing events — “Move the dentist to 2pm.” Only what you ask for changes: reminders, attendees and repeats stay. If the event has attendees, they are notified — on every provider.
• Answer invitations — accept, decline, tentatively accept. The organiser is notified; merely deleting an invitation would leave them expecting you.

Where the second toggle does not apply

It can only be switched on where it can actually work:

• Only at “All details”. If the assistant sees only “Busy” or title and time, it could not even tell you which appointment it is changing. Acting blind is worse than refusing.
• Not for iCal feeds. A subscribed feed is read-only. Google, Microsoft and every CalDAV provider (iCloud, GMX, WEB.DE, mailbox.org, Posteo, STRATO, Disroot, KSuite) work.
• Invitations on CalDAV providers only where the server delivers the answer. With CalDAV, the server itself sends the answer to the organiser. With iCloud this only covers invitations from other iCloud users. Where the server cannot, the assistant points you to your calendar app instead of sending an answer nobody receives. A note with the answer does not travel over CalDAV — the assistant then tells you so.
• Only for events you organise yourself. The assistant cannot rewrite someone else’s invitation. It can decline it for you, and that reaches the organiser.
• Not for synchronised copies. Change a copy and the next sync overwrites it. The assistant refuses and names the source calendar, where the change sticks.

Third toggle: syncs

Since server version 1.6.0 each calendar has a third toggle: “Manage syncs into this calendar”. It requires “create events” and is separate because a sync writes into the calendar continuously and keeps running after you revoke access. It is preselected for new connections. Details under syncs via the assistant.

The safety boundaries

• Recurring invitations ask back. For a series the assistant asks whether you mean this one date or the whole run — unless you named a date. A decline sent to the organiser cannot be taken back.
• Only shared, writable calendars. Write can only be enabled for a calendar you already share for reading. Read-only calendars (e.g. subscribed feeds) never appear as a write target.
• Confirmation happens in the client. Claude Code asks before every write. Turning on auto mode is a deliberate choice.
• Double-booking is reported, not prevented. If a new event overlaps an existing one it’s still created — but the overlap comes back as a warning. Whether a double-booking is intended is your call, not ours.
• Timezone is required. The assistant must send a timezone with every event, so it never lands at the wrong time.

Logging

Every write is in the access log — with calendar, outcome and duration, but without the event’s title. Zero retention applies here too.

Enabling write access later

If you enable write access after the assistant was already connected, it does not know about the new write tools yet — it loaded the tool list when it connected. It will keep telling you it cannot create events.

So after saving in the app, reload the tool list in your client once:

• Claude: open the three-dot menu on the connector and choose Refresh.
• Other clients: reload the connection, or disconnect and connect again. A new token is not needed.

You can switch write access off per calendar at any time, or revoke the access entirely.