Apple Calendar MCP Server

Note: This MCP server requires macOS with Apple Calendar.

A Model Context Protocol (MCP) server that provides Claude with full access to Apple Calendar for smart scheduling, calendar management, and time management assistance.

Features

Calendar Management

• list_calendars - List all available calendars
• create_calendar - Create new calendars
• delete_calendar - Delete calendars
• rename_calendar - Rename existing calendars

Event Operations

• create_event - Create events with natural language date parsing
  • Supports "tomorrow at 3pm", "next Friday", "in 2 hours", etc.
• list_events - List events in a specific calendar
• list_all_events - List events across all calendars
• search_events - Search for events by keyword (searches title, location, description)
• update_event - Update event properties
• delete_event - Delete events
• move_event - Move events between calendars

Smart Scheduling

• find_free_time - Find available time slots
  • Optional business hours filter (9am-5pm)
• check_conflicts - Check for scheduling conflicts
• suggest_optimal_time - AI-powered time suggestions with preferences

Templates

• create_template - Save event configurations as reusable templates
• use_template - Create events from templates
• list_templates - View all saved templates
• delete_template - Remove templates

Analytics

• analyze_schedule - Get insights on:
  • Meeting density (meetings per day)
  • Total time spent in meetings
  • Daily breakdown of schedule

Installation

Prerequisites

• macOS (required for Apple Calendar)
• Node.js 20+ and npm
• Apple Calendar app
• Claude Code CLI

Setup

1. Clone/Install the server:

   cd ~/mcp-servers/calendar
   npm install
   npm run build

2. Grant Calendar Access:

   • System Preferences > Security & Privacy > Privacy > Automation
   • Enable Terminal (or your terminal app) to control Calendar

3. Configure Claude Code:

   The server is already configured in: ~/Library/Application Support/Claude/claude_desktop_config.json

   {
     "mcpServers": {
       "apple-calendar": {
         "command": "node",
         "args": [
           "/path/to/apple-calendar-mcp/dist/index.js"
         ]
       }
     }
   }

4. Restart Claude Code:

   The server will auto-start when Claude Code launches.

Usage Examples

Basic Calendar Operations

"List my calendars"
"Create a calendar called Work"
"Rename the Work calendar to Office"
"Delete the Test calendar"

Creating Events

"Create an event 'Team Meeting' tomorrow at 2pm in the life calendar"
"Schedule 'Dentist Appointment' next Tuesday at 10am with 1 hour duration"
"Add 'Coffee with Sarah' at 3pm today at Starbucks"

Natural Language Date Parsing

The server understands:

• "tomorrow at 3pm"
• "next Friday"
• "in 2 hours"
• "Jan 15 at 10:30am"
• "this weekend"

Smart Scheduling

"Find free time tomorrow for a 1 hour meeting"
"Check if I'm free Friday at 3pm"
"Suggest the best time for a meeting next week, I prefer mornings"
"Find free time during business hours only"

Searching Events

"Search for 'dentist' events this month"
"Find all events with 'meeting' in the title from last week"
"Search for events at 'Starbucks' this year"

Using Templates

"Create a template called 'standup' with 15 minute duration"
"Schedule a standup meeting from template tomorrow at 9am"
"List all my templates"

Analytics

"Analyze my schedule for this week"
"Show insights for next week"
"How busy am I this month?"

Architecture

~/mcp-servers/calendar/
├── src/
│   ├── index.ts                 # Entry point
│   ├── server.ts                # MCP server with all tools
│   ├── applescript/
│   │   ├── bridge.ts            # AppleScript execution wrapper
│   │   ├── calendar-ops.ts      # Calendar CRUD operations
│   │   └── event-ops.ts         # Event CRUD operations
│   ├── utils/
│   │   ├── date-parser.ts       # Natural language date parsing (chrono-node)
│   │   └── conflict-detector.ts # Conflict detection & free time finding
│   └── storage/
│       └── database.ts          # SQLite for templates & history
├── storage/
│   └── calendar.db              # SQLite database (auto-created)
└── dist/                        # Compiled JavaScript

Technical Details

Natural Language Processing

• Uses chrono-node for parsing natural language dates
• Supports relative dates, absolute dates, and common phrases
• Automatically handles time zones and ambiguity

AppleScript Integration

• Direct osascript calls for reliable Calendar access
• Proper date formatting for AppleScript
• String escaping to prevent injection attacks
• Error handling for Calendar API failures

Data Storage

• SQLite database for templates and history
• Settings for default preferences
• Undo history (last 100 operations)

Conflict Detection

• Efficient time slot overlap checking
• Free time finding with configurable intervals
• Business hours filtering
• Optimal time suggestions based on preferences

Configuration

Default settings (stored in SQLite):

• default_calendar: "life"
• default_event_duration: 1 hour (3600000 ms)
• business_hours_start: 9 (9am)
• business_hours_end: 17 (5pm)

Development

Build

npm run build

Development Mode (with auto-reload)

npm run dev

Debug with MCP Inspector

npx @modelcontextprotocol/inspector npx tsx src/index.ts

Troubleshooting

"Calendar access not allowed"

Solution: Grant automation permissions in System Preferences > Security & Privacy > Privacy > Automation

Server not connecting

1. Check logs in ~/Library/Logs/Claude/
2. Verify build succeeded: npm run build
3. Test directly: npx tsx src/index.ts
4. Ensure Calendar.app is not in a broken state

Date parsing fails

• chrono-node handles most common formats
• For edge cases, use explicit formats like "2024-01-15 10:30am"
• Check the input format in the error message

Events not appearing

1. Verify calendar name matches exactly (case-sensitive)
2. Check if Calendar.app is running
3. Refresh Calendar.app view

Future Enhancements

Potential features for v2:

• Recurring events with RRULE support
• Attendee management
• Location autocomplete
• Video conferencing link generation
• iCal import/export
• Proactive schedule optimization
• ML-based event categorization

License

MIT

Author

Built by Null-Phnix