CalDAV MCP server
To connect a CalDAV calendar to an AI agent, add its CalDAV address when you connect the mailbox in Prubex (iCloud, Yahoo and Fastmail fill it in for you). Your agent can then list, create and change events and see when you are free.
Connect CalDAV in 4 steps
- In Prubex, choose Connect an account, then your provider, or Other server.
- For Other server, enter your CalDAV address under Calendars, with the same password as mail or an app password.
- Add Prubex to your agent: in Claude or ChatGPT as a connector (you approve it in Prubex), or with an API key for Cursor, VS Code and other clients.
- Ask your agent for your agenda, or to find a free hour this week.
What your agent can do with CalDAV
| Capability | Supported |
|---|---|
| Read calendars | YesWhere the provider offers CalDAV (iCloud, Yahoo, Fastmail, many hosts). |
| Create and change events | Yes |
| Answer invitations | Yes, by PrubexOnly where the server sends the reply itself (CalDAV scheduling); without a comment. |
| Propose a new time | No |
| Free/busy | Yes, by PrubexComputed from the account’s own calendars. |
| Attendees’ free/busy | No |
| Online-meeting links | No |
| Read mail | Yes |
| Search mail | Yes |
| Conversations | Yes, by PrubexThreads are rebuilt from References and In-Reply-To headers. |
| Folders | Yes |
| Drafts | Yes |
| Send, reply and forward | YesSent over SMTP, with a copy saved to Sent. |
| Flag, label, move and trash | YesMoves need a server with MOVE; labels are single words (IMAP keywords). |
| See what changed | Yes, by PrubexNew mail since the last look, and flag changes where the server reports them. |
Good to know
Checked .
- iCloud, Yahoo and Fastmail calendars connect with their mail.
- Free/busy is worked out from your own calendars.
- Recurring events, including moved and cancelled occurrences, are read in full.
- Answering invitations works where the server sends the reply itself (CalDAV scheduling).
CalDAV questions
Can I connect a calendar without a mailbox?
For a calendar on its own, use its calendar (ICS) link, which connects read-only. Two-way CalDAV connects alongside a mailbox.
Does it work with Nextcloud?
Any standard CalDAV server should work: enter its CalDAV address under Other server. Prubex’s tests run against a standard CalDAV server.
Are recurring meetings supported?
Yes. Prubex expands repeating events, including occurrences that were moved or cancelled.