mac-calendar-mcp

Mac Calendar MCP

Read-only Mac Calendar MCP server with indexed archive search. It exposes Apple Calendar data to MCP clients through a small read surface for listing calendars, browsing event ranges, reading event details, searching archived events, and building agendas.

This package is developed in the apple-app-mcp workspace alongside Mac Mail MCP.

Quick Start

pipx install mac-calendar-mcp

Add to your MCP client:

{
  "mcpServers": {
    "calendar": {
      "command": "mac-calendar-mcp",
      "args": ["--watch", "serve"]
    }
  }
}

Build the Search Index (Recommended)

# One-time setup: approve Full Calendar Access for the helper app
mac-calendar-mcp authorize

mac-calendar-mcp index

The index enables fast archive search and date-range reads from a local SQLite and FTS5 database.

Rebuilds use Calendar's local database when it is readable, then fall back to Apple's supported EventKit API. Calendar.app scripting is retained only as a legacy final fallback. A failed or suspiciously empty refresh never replaces a previously healthy index.

The authorization command installs a small signed helper app under $HOME/Applications. Its stable macOS privacy identity lets the EventKit fallback work consistently from terminals, MCP hosts, and scheduled launchd jobs. Calendar inputs are passed as app arguments rather than interpolated into executable scripts. Each rebuild verifies the helper's code signature, metadata, source hash, compiled script source, and applet executable against a locally built package reference, then launches the signed app bundle itself—not its internal script through osascript.

Run the MCP server with watch mode to keep the index current while events change in Calendar.app:

mac-calendar-mcp serve --watch

The server performs a background sync at startup. Watch mode then checks Calendar's local SQLite database, WAL, and SHM files every 3600 seconds and refreshes the index when those files change. Override the interval with --watch-interval SECONDS when you need faster or slower updates.

Configure (Optional)

mac-calendar-mcp init   # writes ~/.mac-calendar-mcp/config.toml

Mac Calendar MCP reads settings from environment variables and an optional TOML config file at $HOME/.mac-calendar-mcp/config.toml. The init command writes a commented template with every available key and refuses to overwrite an existing config unless --force is passed.

Common environment variables:

Variable	Purpose
APPLE_CALENDAR_INDEX_PATH	Override the SQLite index location.
APPLE_CALENDAR_INDEX_SOURCE	Snapshot source: auto (default), store, eventkit, or jxa.
APPLE_CALENDAR_INDEX_STALENESS_HOURS	Hours before an index is considered stale.
APPLE_CALENDAR_INDEX_CALENDARS	Comma-separated calendar names or IDs to index; unset indexes all calendars.
APPLE_CALENDAR_INDEX_PAST_YEARS	Historical indexing window; defaults to 1 year.
APPLE_CALENDAR_INDEX_FUTURE_YEARS	Limit future indexing window.
APPLE_CALENDAR_DEFAULT_CALENDARS	Comma-separated tool-default calendar names or IDs when calendar_ids is omitted.

[defaults].calendars only controls MCP tool defaults. [index].calendars controls which calendars are stored in the local search index.

Tools

Tool	Purpose
list_calendars()	List accessible calendars
get_events(start, end, calendar_ids?, limit?, offset?)	List event occurrences in a date range
get_event(event_id, occurrence_start?)	Get full event or occurrence detail
search_events(query, start?, end?, calendar_ids?, fields?, limit?, offset?)	Search indexed event archives
get_agenda(start?, days?, calendar_ids?)	Chronological agenda helper
calendar_index_status()	Index health and coverage summary

All tools are read-only. The server does not create, update, delete, RSVP, subscribe to calendars, or open Calendar.app UI in v1.

Search and Indexing

Calendar search is backed by SQLite and FTS5. Indexed fields include event title, location, notes, URL, attendee names/emails, and calendar name.

Recurring events are expanded into occurrence rows for listing and search. The current recurrence layer supports common daily, weekly, monthly, and yearly patterns, including intervals, counts, until dates, weekly BYDAY, and Calendar exception dates. Unsupported recurrence rules are counted in index status instead of being silently treated as complete.

Configuration

Per-client env overrides via the MCP client's launch config work:

{
  "mcpServers": {
    "calendar": {
      "command": "mac-calendar-mcp",
      "env": {
        "APPLE_CALENDAR_DEFAULT_CALENDARS": "Work,Personal",
        "APPLE_CALENDAR_INDEX_FUTURE_YEARS": "2"
      }
    }
  }
}

The default index path is $HOME/.mac-calendar-mcp/index.db.

CLI Usage

All read tools are also available as standalone CLI commands:

mac-calendar-mcp calendars
mac-calendar-mcp authorize
mac-calendar-mcp init
mac-calendar-mcp index
mac-calendar-mcp status
mac-calendar-mcp search "quarterly planning" --limit 10
mac-calendar-mcp events 2026-05-01 2026-06-01 --limit 50
mac-calendar-mcp agenda --days 7
mac-calendar-mcp rebuild
mac-calendar-mcp rebuild --verbose  # source and snapshot counts

All data commands output JSON where practical.

Development

git clone https://github.com/wagamama/apple-app-mcp
cd apple-app-mcp
uv sync
uv run ruff check packages/mac-calendar-mcp/src
uv run --package mac-calendar-mcp pytest packages/mac-calendar-mcp/tests
uv build --package mac-calendar-mcp

See CALENDAR.md for domain architecture, tool design, testing guidance, and implementation notes.

License

GPL-3.0-or-later