Connect all your calendars to Claude, ChatGPT or Gemini
Your AI assistant is great at juggling your week, right up until your week lives in three calendars it can't see. Here's how to hand it the whole picture, read-only.
Updated November 11, 2026
Why one calendar isn't enough
Most assistants connect to one calendar at a time, usually a single Google account. Ask "when am I free on Thursday?" and the answer ignores your client's Outlook, your Zoho calendar and the family plans on your iPhone. That's how a "free" slot turns into a double-booking. 🙈
Syncydo already brings those calendars together. Connect your assistant to Syncydo once, and it can read all of them in one go.
What your assistant can do
- List calendars: every calendar you've connected, and where each one comes from.
- Get agenda: your meetings across every calendar, up to 60 days ahead, with join links and whether you've said yes.
- Find free time: open slots of any length that are free in every calendar, inside your working hours and time zone.
It's strictly read-only. Your assistant can look, never touch: it can't add, move or delete anything.
Before you start
- A Syncydo account with your calendars connected. Google, Microsoft 365 and Outlook, Zoho, and the calendars on your iPhone (including iCloud) all count.
- Syncydo Plus or Pro. The assistant connection comes with both.
- The Syncydo address for your assistant:
https://app.syncydo.com/mcp
Claude
- On claude.ai, open Customize, then Connectors.
- Choose + Add, then Add custom connector. Name it Syncydo, paste
https://app.syncydo.com/mcpand choose Continue, then Add. - Sign in to Syncydo and choose Allow.
Works on every Claude plan (the free plan allows one custom connector). On Team and Enterprise, an owner adds it for the organization first, then you choose Connect.
ChatGPT
- On chatgpt.com (on the web), open Plugins, choose the + button, then Add custom MCP server.
- Name it Syncydo, paste
https://app.syncydo.com/mcpunder Connection, tick I understand and want to continue and choose Create as a plugin. - Sign in to Syncydo and choose Allow.
Custom connections are for ChatGPT Pro, Business and Enterprise, added on the web. On Business, an admin or owner sets it up.
Gemini
- On gemini.google.com, open Settings, then Connected Apps (or Personal Intelligence, then Connected Apps).
- Under Custom apps, choose Add a custom app, paste
https://app.syncydo.com/mcpand choose Next. - Sign in to Syncydo and choose Allow.
For now Google offers custom apps in the US, in English, on personal Google accounts, with Keep Activity on. Add it on the web and it works in the Gemini app too.
Things to ask
- "What's on this week across all my calendars?"
- "Find me 45 minutes on Thursday afternoon that's free everywhere, Vancouver time."
- "Do any of my meetings next week overlap?"
- "Which invitations haven't I answered yet?"
What it sees, and how to stop it
Your assistant sees what you'd see in Syncydo: meeting times, titles, calendars and join links. Calendars kept only on your phone share just their busy times, so they shape free time without giving anything away. What the assistant does with that is up to the company behind it, under its own terms.
Changed your mind? Disconnect the assistant any time from Configure in Syncydo, or remove the connector in your assistant's settings. More on what Syncydo keeps is on What Syncydo can see.
Questions
Can the assistant change my calendar?
No. The connection is read-only: it can list calendars, read your agenda and find free time, and nothing else.
Which plan do I need?
Plus or Pro. The free plan keeps 2 calendars in sync, without the assistant connection.
Do my iPhone calendars count?
Yes, for free time. They share only busy times, so they block slots without the assistant seeing the details.
How do I disconnect it?
In Syncydo, open Configure and disconnect the assistant, or remove the connector in your assistant's own settings.
More guides
- How to show your personal calendar as Busy at workStop colleagues booking over your personal appointments. The built-in ways in Outlook and Google Calendar, where they fall short, and how to block the time automatically without sharing details.
- How to sync Google Calendar and Outlook both waysTwo-way sync between Google Calendar and Outlook or Microsoft 365: the free subscribe-by-link method, why it's one-way and slow, and how to keep both calendars blocking time for each other.
- How to stop getting double-booked across calendarsWhy double-booking happens when you have more than one calendar, a simple routine to prevent it, and how to make every calendar block time for the others automatically.
- How to sync a Microsoft 365 or Teams calendar with Google CalendarGet your Microsoft 365 and Teams meetings into Google Calendar, or the other way around: the free publish-and-subscribe method, what IT may block, and how to keep both calendars blocking time.
- How to see two Google accounts' calendars in one placeCombine a work Google Workspace calendar and a personal Gmail calendar into one view: the free sharing method, what it doesn't do, and how to make each account block time for the other.
- One calendar view when you run several companiesFounders and fractional executives with a Google Workspace or Microsoft 365 account per company: how to see every company's calendar in one place and stop each one booking over the others.
- How to sync Zoho Calendar with Google Calendar or OutlookZoho Calendar with Google Calendar or Outlook: Zoho's own Google sync and its limits, sharing by iCal link, and how to make Zoho and your other calendars block time for each other.
- How to add your iCloud calendar to OutlookGet your iCloud (Apple) calendar into Outlook on Windows, the web or Mac, what each method can and can't do, and how to stop your iPhone plans and work meetings clashing.