BusyCal MCP Server

Claude Desktop extension that lets AI agents read and manage calendars, events, tasks, and availability through the BusyCal macOS app, fully local.

Collaboration by BusyMac / Beehive Innovations None active

GitHub Docs

Overview

BusyCal MCP is an official Claude Desktop extension that connects AI agents to the BusyCal macOS calendar application. It exposes the user's calendars, events, and tasks to Claude so the assistant can search items, check free/busy availability, find open meeting slots, and create, update, move, or delete events and tasks through natural conversation. The extension is distributed as a signed .mcpb bundle from BusyMac and from the BeehiveInnovations/busycal-mcpb GitHub releases page.

The integration runs entirely locally on the Mac. BusyCal MCP talks directly to the BusyCal app on the same machine and does not relay calendar data through any external BusyMac or third-party service. Any changes the agent makes flow back through BusyCal's own sync to the user's connected calendar accounts (iCloud, Google, Microsoft 365, etc.).

The bundle ships 16 tools covering account and calendar discovery, multi-type search across events, tasks and journals, availability queries with working-hours awareness, IANA timezone aware event creation, reminders, task deferral and completion, and item deletion. It is positioned as the official AI control surface for BusyCal users who want Claude to act as a scheduling assistant without giving up local data privacy.

Tools

Tool	Description
`list_accounts`	List the calendar accounts configured in BusyCal.
`list_calendars`	List calendars across accounts, including whether each supports events or tasks.
`query_items`	Search across events, tasks, journals, graphics, and stickies by keyword, date range, or calendar.
`query_events`	Search calendar events by keyword, date range, and calendar.
`query_tasks`	Search tasks by keyword, due date, completion state, and calendar.
`query_availability`	Check free/busy availability across selected calendars over a time window.
`find_next_available`	Find the next open time slot of a given duration based on availability and working hours.
`create_event`	Create a calendar event with title, notes, all-day flag, IANA timezone, and reminders.
`create_task`	Create a task on a task-capable calendar with due date, notes, and reminders.
`update_event`	Update fields on an existing event such as title, time, notes, or reminders.
`update_task`	Update fields on an existing task.
`move_event`	Reschedule an event to a new start/end time, optionally with a new timezone.
`defer_task`	Defer a task's due date by a relative or absolute amount.
`complete_task`	Mark a task as complete.
`uncomplete_task`	Mark a previously completed task as not done.
`delete_event`	Delete an event from BusyCal.
`delete_task`	Delete a task from BusyCal.

Setup Guide

Prerequisites

macOS with BusyCal 2026.1.3 or later installed in /Applications or /Applications/Setapp
Claude Desktop for macOS, version 0.11.0 or later, with extension support enabled
No API keys or external accounts required

Install the extension

Download the latest busycal.mcpb bundle from either:
- The BusyMac docs page: busymac.com/docs/busycal/70624-mcp
- GitHub Releases: github.com/BeehiveInnovations/busycal-mcpb/releases
Open Claude Desktop and go to Settings > Extensions > Advanced Settings.
Click Install Extension and select the downloaded busycal.mcpb file.
Accept the install prompt. The standard sideload warning appears, but BusyCal remains sandboxed and can only access its own calendar data.
Verify by opening a new Claude chat and asking: List my BusyCal calendars.

Notes on configuration

BusyCal MCP is installed as a signed .mcpb bundle, so there is no manual claude_desktop_config.json entry to edit. Claude Desktop registers the server automatically once the bundle is installed. The extension communicates with BusyCal locally over an on-device channel, so no environment variables, tokens, or URLs need to be set.

// No manual config required. The .mcpb bundle is registered by Claude Desktop.
// Managed via Settings > Extensions > BusyCal.

Use Cases

Ask Claude to find the next free 30 minute slot across your work calendars during business hours and book a focus block.
Bulk reschedule or defer overdue tasks based on natural language instructions like "push everything due this week to next Monday".
Cross-timezone meeting creation using IANA timezone identifiers so events land correctly for Pacific, Eastern, or international attendees.
Pull a daily briefing of today's events and open tasks from BusyCal at the start of the workday.
Triage and clean up calendar clutter by searching for duplicate events, declined invites, or stale tasks and deleting them.

Example Prompts

"List my BusyCal calendars and tell me which ones support tasks."
"Find the next 45 minute slot I have free between 9am and 5pm Pacific this week."
"Create an event called 'Design review' tomorrow from 2 to 3pm Eastern in my Work calendar with a 10 minute reminder."
"Show me all incomplete tasks due before Friday and defer the low priority ones to next week."
"Search my calendar for any events with 'Acme' in the title over the past 30 days and summarize them."

Pros

Official, signed Claude Desktop extension distributed by BusyMac in partnership with Beehive Innovations.
Fully local: calendar data never leaves the Mac and no API keys or cloud relays are involved.
Comprehensive 16-tool surface covering read, create, update, move, complete, and delete for both events and tasks.
Timezone-aware scheduling with IANA identifiers and working-hours-aware availability checks.

Limitations

macOS only and requires the paid BusyCal app (version 2026.1.3 or later) installed locally.
Currently packaged for Claude Desktop via .mcpb bundle, so using it with other MCP clients is not a documented path.
Source for the underlying server is not in the public bundle repo, which limits inspection and self-hosting.

Alternatives

Apple Calendar MCP community servers for users on stock macOS Calendar without BusyCal.
Google Calendar MCP for cloud-first Google Workspace calendar control.
Cal.com MCP server for scheduling-focused workflows on top of Cal.com booking links.