Connect Cursor

In Cursor you add Kalender Sync as a remote MCP server. Cursor’s agent then knows your calendars across every connected provider — Google, Outlook, iCloud, GMX, WEB.DE and more.

1. Create the access and key in Kalender Sync

No account yet? Create one at app.kalender-sync.de (7 days of Professional free, no credit card) and connect your calendars.

In the app, open AI assistant → Connect the assistant and choose Something else. As with every access, you pick the calendars one by one and set the detail level per calendar — calendars you don’t share don’t exist for Cursor.

Create key gives you your access key (a token starting with ksa_). It is shown only once. Treat it like a password: whoever holds the key holds exactly the access you gave this connection. Never paste it into a chat.

Why a key and not a sign-in window?

Sign-in through a browser window (OAuth) is currently available for Claude and ChatGPT only. Cursor therefore connects with an access key. Your permissions work exactly the same: you still decide per calendar what is visible and whether events may be created.

2. Add Kalender Sync in Cursor

1. Store the key as the environment variable KALENDER_SYNC_KEY in your shell profile or system environment (Cursor doesn’t read envFile for remote servers). Alternatively paste it directly instead of ${env:KALENDER_SYNC_KEY} — then keep the file out of any Git repository.
2. Add the entry to ~/.cursor/mcp.json (all projects) or .cursor/mcp.json (this project only). Existing servers stay as they are:

{
  "mcpServers": {
    "kalender-sync": {
      "url": "https://app.kalender-sync.de/mcp",
      "headers": {
        "Authorization": "Bearer ${env:KALENDER_SYNC_KEY}"
      }
    }
  }
}

3. Reload Cursor. kalender-sync and its tools should appear under Settings → MCP.

Then dive right in, e.g.: “Which calendars are shared via Kalender Sync?”, “Where do I have two hours in one block this week?” or “When is my dentist appointment?”

Troubleshooting

• 401 / “Unauthorized”: the key is mistyped, expired or revoked. Check the header: name exactly Authorization, value Bearer ksa_… (with the space). If in doubt, create a fresh key.
• A calendar is missing: it isn’t shared with this access. Add it in the app under AI assistant → Edit sharing — changes apply immediately, no new key needed.

Revoke access

In Kalender Sync under AI assistant, click Revoke on the access — effective immediately; the key is dead regardless of what is stored in Cursor. More under Revoke access.