Your AI speaks calendar now.
Every account. One interface.
Kalender Sync connects Claude and ChatGPT to all your calendars – Outlook, Google, iCloud, GMX, WEB.DE & co. at once, through a single connection. No more stitching together individual logins or API keys. Gemini and Mistral are coming soon.
That turns the chatbot into a real assistant: it knows what your day looks like – plans with you, finds slots, books events and gives answers that fit your life instead of anyone's.
Supported assistants
Claude 
Claude Code 
ChatGPT 
Gemini soon 
Mistral soon Connect your assistant
One click opens Claude with the address pre-filled – Claude Code and ChatGPT work the same way. No API keys, no fiddling; the connection is up in two minutes.
Grant your calendars
Pick the calendars your assistant should know – work, personal, side project. From now on it sees your whole schedule, no matter which provider it lives with.
Hand off the work
"Where do I have two free hours this week?" – "Put the call on Tuesday at 10." Your assistant answers across all calendars and books events straight into the right one.
All your calendars. One interface.
Other tools connect your AI to one account – we connect it to your entire schedule. Outlook, Google, iCloud, GMX, WEB.DE, mailbox.org, kSuite: one connection, and your assistant sees it all together. Your account logins never leave your hands – access runs centrally through Kalender Sync, and you manage everything in one place. "Where am I actually free?" now means: across every calendar at once.
From AI to assistant
An AI without your calendar gives generic answers. With it, it thinks along: it plans your day, suggests slots that are actually free, drafts the email with the meeting proposals right away – and from the Basic plan books the event itself. Everything your assistant can do, it can now do with your schedule in mind.
You decide what your AI sees
Per calendar you pick the detail level: busy only, title + time, or full details. Calendars you don't grant simply don't exist for the assistant – and attendees, attachments and links are never shared.
Safe by design
Your existing events can't be changed or deleted by the AI – it can't even address them. Every access can be revoked instantly (kill switch included), every query is logged. GDPR-compliant, hosted in Germany.
FAQ
Frequently asked questions about the AI assistant
What is MCP?
MCP (Model Context Protocol) is an open standard that lets AI assistants like Claude or ChatGPT access external services securely. Kalender Sync provides an MCP server that makes your calendars available to your assistant – on your terms.
Which AI assistants are supported?
Claude (web and desktop), Claude Code and ChatGPT (via developer mode). Gemini and Mistral are coming soon. Technically, any MCP-capable client works.
What does the assistant see of my events?
You decide per calendar: busy only, title + time, or full details. Attendees, attachments and links are never shared – and calendars you don't grant simply don't exist for the assistant.
Can the AI change or delete my existing events?
No. From the Basic plan the assistant can create events and manage only the ones it created itself. Your existing events aren't technically addressable for it – that's architecture, not a rule.
What does the AI assistant cost?
Reading availability is included on all plans; creating events starts with Basic (€4/month). New accounts test all Business features free for 14 days – no credit card.
How do I revoke access?
Any time with one click under "AI assistant" in the app – effective immediately. A kill switch ends all connections at once, every query is logged, and unused connections expire automatically.
Ready for an agent that truly knows your calendars?
Try free for 14 daysCurrently supported providers
Google Microsoft Apple iCloud KSuite GMX WEB.DE mailbox.org iCal-FeedsNewsletter
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