Google Calendar MCP

Google Calendar MCP

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A1 Google Calendar MCP lets an AI app manage Google Calendar in plain language. Review your week, schedule a meeting with guests and a Google Meet link, reschedule or cancel it, find a slot when everyone is free, and block Out of Office or Focus Time.

It uses the Google Calendar API with your Google account. It distinguishes a whole recurring series from a single occurrence and makes the limits of the Calendar API explicit instead of implying that every calendar task is possible.

• 19 tools. Inspect calendars, events and free/busy, create and edit events, expand recurring series, and block Out of Office and Focus Time — plus six for connecting your Google account.
• Sign in from the chat. No credentials file to hand-write: ask the assistant to connect, approve access in the browser, and the very next request works — no restart. The client secret travels as a file path, never through the conversation.
• Nobody is emailed by accident. The Calendar API's default for invitations, changes and cancellations is silence; guests get email only when you ask for it via send_updates.
• Writes are never replayed. After an ambiguous failure the server does not retry a write — a duplicated event could re-email every guest.
• Minimal Google scopes. It uses calendar.events and calendar.readonly, without the broad calendar scope.

Start with a read-only question:

What's on my calendar this week? Point out any overlapping meetings.

Connect the server · Explore use cases · Open technical documentation

See it work in a minute

You: What does my Thursday look like, and when are Anna and I both free?

Assistant: Shows Thursday's events and the free slots you share. Nothing changes.

You: Book a 45-minute design review with Anna in the first shared slot, with a Google Meet link.

Assistant: Shows the proposed time, guest list and Meet link, then asks for confirmation before creating the event.

You: Confirm.

Assistant: Creates the event. Nobody gets an email unless you ask it to send invitations.

Contents

• Quick start
• What you can ask it to do
• How an event changes
• What can change
• Getting access
• Configuration
• Data, limits and background work
• Technical documentation
• Support

Quick start

You need Node.js 20+, a Google account and OAuth credentials from a Google Cloud project with the Google Calendar API enabled.

1. Prepare Google OAuth access.
2. Add the server to your AI app.
3. Ask the read-only question above.

In the app: open Settings → MCP servers, select Add server, choose STDIO, enter the command npx -y @a1-x-tech/mcp-google-calendar@latest and environment variables GOOGLE_CALENDAR_CLIENT_ID, GOOGLE_CALENDAR_CLIENT_SECRET, GOOGLE_CALENDAR_REFRESH_TOKEN, then select Save and Restart.

From the command line:

codex mcp add google-calendar \
  --env GOOGLE_CALENDAR_CLIENT_ID=your_client_id \
  --env GOOGLE_CALENDAR_CLIENT_SECRET=your_client_secret \
  --env GOOGLE_CALENDAR_REFRESH_TOKEN=your_refresh_token \
  -- npx -y @a1-x-tech/mcp-google-calendar@latest

codex mcp list

Codex MCP documentation

claude mcp add \
  --env GOOGLE_CALENDAR_CLIENT_ID=your_client_id \
  --env GOOGLE_CALENDAR_CLIENT_SECRET=your_client_secret \
  --env GOOGLE_CALENDAR_REFRESH_TOKEN=your_refresh_token \
  --transport stdio --scope user google-calendar \
  -- npx -y @a1-x-tech/mcp-google-calendar@latest

claude mcp list

Claude Code MCP documentation

The current official path is Settings → Extensions. For a custom desktop extension, open Advanced settings → Extension Developer → Install Extension…, select a .mcpb file and follow the prompts.

This repository currently publishes an npm stdio package and does not contain a .mcpb bundle. For Claude Desktop builds that still support local configuration, use the following JSON stdio configuration as a fallback:

{
  "mcpServers": {
    "google-calendar": {
      "command": "npx",
      "args": ["-y", "@a1-x-tech/mcp-google-calendar@latest"],
      "env": {
        "GOOGLE_CALENDAR_CLIENT_ID": "your_client_id",
        "GOOGLE_CALENDAR_CLIENT_SECRET": "your_client_secret",
        "GOOGLE_CALENDAR_REFRESH_TOKEN": "your_refresh_token"
      }
    }
  }
}

In those builds, save it to ~/Library/Application Support/Claude/claude_desktop_config.json on macOS or %APPDATA%\Claude\claude_desktop_config.json on Windows.

Claude Desktop MCP documentation

Add this to ~/.cursor/mcp.json on macOS/Linux or %USERPROFILE%\.cursor\mcp.json on Windows:

{
  "mcpServers": {
    "google-calendar": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@a1-x-tech/mcp-google-calendar@latest"],
      "env": {
        "GOOGLE_CALENDAR_CLIENT_ID": "your_client_id",
        "GOOGLE_CALENDAR_CLIENT_SECRET": "your_client_secret",
        "GOOGLE_CALENDAR_REFRESH_TOKEN": "your_refresh_token"
      }
    }
  }
}

Cursor MCP documentation

Run MCP: Open User Configuration and add:

{
  "servers": {
    "google-calendar": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@a1-x-tech/mcp-google-calendar@latest"],
      "env": {
        "GOOGLE_CALENDAR_CLIENT_ID": "${input:calendar_client_id}",
        "GOOGLE_CALENDAR_CLIENT_SECRET": "${input:calendar_client_secret}",
        "GOOGLE_CALENDAR_REFRESH_TOKEN": "${input:calendar_refresh_token}"
      }
    }
  },
  "inputs": [
    { "type": "promptString", "id": "calendar_client_id", "description": "Google OAuth client ID" },
    { "type": "promptString", "id": "calendar_client_secret", "description": "Google OAuth client secret", "password": true },
    { "type": "promptString", "id": "calendar_refresh_token", "description": "Google OAuth refresh token", "password": true }
  ]
}

Check it with MCP: List Servers.

VS Code MCP documentation

What you can ask it to do

See your schedule

• What meetings do I have this week? Include the recurring ones.
• Show tomorrow's 1:1 with its guests, Meet link and reminders.
• List every occurrence of the team sync in March.

Plan and change meetings

• Create a 45-minute review on Thursday with two guests and a Google Meet link.
• Reschedule the retro one hour later and update the guest list — but don't email anyone yet.
• Move the planning event to the team calendar.
• Cancel Friday's occurrence of the standup, leaving the rest of the series alone.

Protect your time

• When are Anna, Boris and I all free for an hour next week?
• Block Out of Office for my vacation and auto-decline new invitations.
• Create two hours of Focus Time tomorrow morning and silence Google Chat.

How an event changes

1. calendar_id: "primary" is your main calendar; other calendars come from list_calendars, and writes need writer access.
2. A recurring series and a single occurrence have different ids: the series id changes or cancels every occurrence, an instance id (from list_event_instances) exactly one.
3. update_event changes only the fields you provide, but a nested object replaces its predecessor wholesale — a new attendees list replaces the whole guest list.
4. No write emails anybody unless send_updates says so — the Calendar API's default is silence.

Out of Office and Focus Time blocks exist only on the primary calendar of a Google Workspace account; consumer Gmail and secondary calendars reject them. Creating an event does not check for conflicts — ask for a free/busy check first. All-day events end on an exclusive date: an event through Friday ends on Saturday's date.

What can change

The AI client controls confirmation prompts. The server marks reads, writes and destructive tools so the client can distinguish an inspection from a live change.

Getting access

Access to your own calendars requires OAuth 2.0; an API key is not enough. There are two ways to connect, and the first one needs no configuration file at all.

Sign in from the chat

Start the server with no credentials and ask the assistant to connect. It walks you through it with six built-in tools:

The login takes effect immediately: the next tool call works without restarting the AI client. The token is stored in ~/.config/mcp-google-calendar/credentials.json (on Windows, under %APPDATA%), readable only by your account, and never leaves your machine.

Or configure environment variables

The classic path, and the one to use for CI and headless installs:

1. Create or select a Google Cloud project and enable Google Calendar API.

2. Configure the OAuth consent screen and create a Desktop app OAuth client.

3. Authorize the Google account whose calendars you want to manage. The OAuth 2.0 Playground can obtain the refresh token when Use your own OAuth credentials is enabled.

4. Request both scopes:

   https://www.googleapis.com/auth/calendar.events
   https://www.googleapis.com/auth/calendar.readonly
   

   The broad https://www.googleapis.com/auth/calendar scope is needed only for raw_request calls that manage calendars or sharing rules themselves.

Environment variables always win over a login taken in the chat, so an existing configured install keeps behaving exactly as before.

Testing-mode OAuth refresh tokens can expire after seven days. Publish the OAuth app, or use an Internal app in a Workspace domain, when you need long-lived access. Treat the client secret and refresh token as passwords.

Configuration

* Provide either the OAuth trio or an access token. Without credentials the server still starts and completes the MCP handshake; the first tool call then names the exact variables to set.

Data, limits and background work

• Requests go to Google Calendar. The local server refreshes Google OAuth tokens and calls the Calendar API. Its anonymous telemetry contains an installation ID, package version, AI client and platform versions, and tool names — never OAuth tokens, calendar data, tool arguments or prompts. Set ASKADS_TELEMETRY=0 to opt out.
• Google applies per-project quotas. On 429, the server retries with backoff; reads also retry after network and 5xx errors, while writes are not replayed after an uncertain failure — a duplicated event could re-email every guest.
• There is no background polling. The server runs only when called. list_events supports incremental checks via updated_min; if your AI app supports scheduled tasks, it can check your calendar periodically.

Technical documentation

• MCP capability catalog — task-oriented pages for every tool.
• All tools and inputs
• Development documentation
• Publishing documentation
• Google Calendar API reference

Support

Found a bug or need a scenario? Create an issue or write in Telegram.