Lucie Sync for AI assistants
Lucie Sync exposes a remote Model Context Protocol (MCP)server that lets an AI assistant check when someone is free, book a meeting, and find a time that works across a whole group — without that person's raw calendar ever being shared. The assistant sees only the slots a host chooses to offer and the rules around them; it has no tool that can read calendar events, so it never learns what those meetings are, who they are with, or what they are called.
Connect it
Add this URL as a custom connector in Claude, or in any MCP client that supports remote servers over Streamable HTTP or SSE:
https://sync.lucie.network/api/mcp
That base URL gives you the free tools. To use the Sync Pro group tools, you need your personal connector URL instead — it ends in ?k=… and identifies you as its owner. Generate it in Lucie Sync under Settings → AI assistants, then add that URL as the connector. Treat it like a password: anyone holding it can act as you.
What the assistant can do
Five tools, three of them free:
check_availabilityRead-onlyReturns a host's open slots and their booking rules — durations offered, minimum notice, how far ahead you can book, buffer between meetings. Never returns calendar contents.
book_meetingWritesBooks a confirmed meeting at a specific slot. Creates the calendar event and emails both sides. Requires the booker's name, email and a short reason, which is shared with the host.
find_group_timesRead-onlyIntersects the availability of several Lucie hosts and returns the times when all of them are free. Read-only — nothing is booked or created.
create_group_eventWritesSync ProCreates a group poll pre-filled with everyone's common times and returns a vote link to share. People without a Lucie handle can vote too. Sends no emails and touches no calendars.
book_group_meetingWritesSync ProBooks one shared calendar event across several hosts at once, with everyone invited. Re-verifies that every participant is free at that instant and refuses if anyone isn't, so it never double-books.
The two writes that touch a calendar — book_meeting and book_group_meeting — are annotated as write operations, so a well-behaved client asks you to confirm before either one runs.
What it never does
- It cannot read your calendar. No tool returns events, titles, attendees or descriptions. Lucie computes free/busy internally and returns only bookable slots.
- It cannot see your other bookings. An assistant querying your handle learns when you are open, not who else has booked you.
- It cannot act as you without your connector. The group tools are gated on the personal
?k=URL, not on a self-declared email address, so an assistant cannot claim to be someone it isn't.
Full detail in the privacy policy.
Time zones
Every slot is an absolute instant in ISO-8601 UTC. Pass the booker's IANA time zone (for example Asia/Singapore) and times are presented in their local zone, so nobody has to do time-zone arithmetic. Confirmation emails and reminders follow the same zone.
Support
Questions, bug reports or access problems: support@lucie.network.
Frequently asked
- Does the connector give an AI assistant access to my calendar?
- No. The connector exposes computed availability — the open slots you offer and the rules around them. It has no tool that reads calendar events, so an assistant cannot see what your meetings are, who they are with, or what they are called. Your raw calendar never leaves Lucie.
- Do the people booking me need a Lucie account?
- No. Anyone can book you through your page at lucie.network/book/@yourhandle without an account, and an assistant on their side can book you through the connector without one either. Only hosts — the people being booked — have Lucie accounts.
- Which AI assistants can use this?
- Any MCP client that supports remote servers over Streamable HTTP or SSE. That includes Claude via a custom connector, and any other assistant or agent framework that speaks the Model Context Protocol.
- Can two people's assistants schedule a meeting with each other?
- Yes. Every Lucie handle is a live endpoint, so one person's assistant can query another person's availability and book against it directly. find_group_times extends that to several handles at once, returning only the times when everyone is free.
- What does it cost?
- Checking availability, booking 1:1 meetings and finding common times across a group are free. Creating group polls and booking a group meeting onto everyone's calendar require Sync Pro.
- What happens if a slot is taken between checking and booking?
- The booking is refused rather than double-booked. Every write re-verifies availability at the moment it runs, against every calendar the host has connected.