@cocal/google-calendar-mcp

What it does

Provides Google Calendar integration for Claude and other AI assistants. Manages calendar events across multiple Google accounts and calendars simultaneously, with support for creating, updating, deleting, and querying events. Includes conflict detection across calendars, free/busy availability checks, natural language date/time understanding, and the ability to import calendar events from images, PDFs, or URLs.

Who it's for

Product managers and engineers juggling multiple calendars (personal, work, project-specific) who want Claude to surface scheduling conflicts or suggest meeting times. Also useful for teams managing shared calendars and needing AI-powered availability analysis across accounts.

Common use cases

• Query availability across personal and work calendars for a given timeframe
• Detect overlapping events across multiple calendars or accounts
• Create calendar events from natural language descriptions
• Import events from screenshots or PDFs of agendas
• Check free/busy status across multiple accounts before suggesting meeting times

Setup pitfalls

• Google Cloud setup is multi-step: create a project, enable the Calendar API, create OAuth credentials (must select Desktop app type), and add your email as a test user. Test users can take several minutes to propagate, blocking initial OAuth setup.
• Tokens expire after 7 days in test mode, requiring weekly re-authentication. Publish your app to production mode to avoid this, though Google will flag the app as unverified.
• The GOOGLE_OAUTH_CREDENTIALS environment variable must point to your OAuth credentials JSON file and is required for npx-based setups. Misconfigured paths cause -32600 errors on first use.
• Marked as high-risk due to filesystem and network access — ensure the credentials file and OAuth tokens are stored securely, particularly when running in shared environments.