ics-calendar

ICS Calendar — Claude Code Plugin

A Claude Code plugin that gives Claude full read and write access to your macOS Calendar (including any iCloud, Google, or Exchange calendars visible in Calendar.app) via Apple's native EventKit framework.

No app-specific passwords. No CalDAV. No credential storage. The plugin reads and writes the same local Calendar database that Calendar.app uses.

Looking for the Claude Desktop (.mcpb) version? See ical-dxt.

Requirements

• macOS 13.0 (Ventura) or later, Apple Silicon (arm64)
• Claude Code
• Calendar.app set up with at least one calendar (iCloud, Google, Exchange, or local)
• Node.js 18+ on PATH (used to run the bundled MCP server)

Installation

Via marketplace

/plugin marketplace add alexey-max-fedorov/ics-plugin
/plugin install ics-calendar@ics-calendar-plugins

Local checkout (development)

/plugin marketplace add /Users/alexey/Projects/ics-plugin
/plugin install ics-calendar@ics-calendar-plugins

After install, build the bundled bridge binary and MCP server:

cd /Users/alexey/Projects/ics-plugin
pnpm install
pnpm build

The first time Claude calls a calendar tool, macOS will prompt for permission. Click "Allow Full Access".

If you ever need to grant or revoke permission manually: System Settings, Privacy and Security, Calendars.

Tools

Tool	Purpose
list_calendars	List all calendars Claude can see
get_events	Fetch events in a date range
search_events	Full-text search across event title, location, notes
create_event	Create a new event
update_event	Update fields of an existing event
delete_event	Delete an event
get_availability	Return free/busy blocks for scheduling
get_current_datetime	Return the host machine's current local date, time, and timezone

All event timestamps are emitted in your local timezone with offset (e.g. 2026-05-09T15:00:00-07:00).

Troubleshooting

"Calendar access denied"

macOS denied calendar permission, or you have not granted it yet. Open System Settings, Privacy and Security, Calendars, and turn on the toggle for "ICS Calendar Bridge".

If the toggle is missing, the OS has not asked yet. Restart Claude Code and trigger any calendar tool.

"Bridge binary not found"

Run pnpm build in the plugin directory. The build produces bin/ICSBridge.app which ${CLAUDE_PLUGIN_ROOT}/bin/ICSBridge.app resolves to.

Calendar changes are not visible immediately

EventKit syncs through the macOS Calendar service. iCloud changes can take a few seconds to propagate.

Privacy

See PRIVACY.md. All calendar data stays on your local machine. No telemetry. No network calls.

License

See LICENSE. Noncommercial use only; contact the author for commercial licensing.

Build from source

Requirements: Node 18+, pnpm 11+, Swift 5.9+, Xcode command line tools.

pnpm install
pnpm build
pnpm test

Version Bump

./bump-version.sh <version> — syncs version across package.json, .claude-plugin/plugin.json, and .claude-plugin/marketplace.json.