EventKit MCP Server

A Swift-based Model Context Protocol (MCP) server that exposes Apple Reminders via the EventKit framework. Built using the official MCP Swift SDK.

Overview

This MCP server allows AI assistants to interact with Apple Reminders, enabling them to:

• List, create, update, and delete reminders
• Manage reminder lists (calendars)
• Search reminders by content
• Filter reminders (overdue, today, upcoming)
• Restrict access to specific lists for security

Scope: Reminders only. Calendar events are not currently supported, despite EventKit covering both.

Requirements

• macOS 14.0 or later
• Swift 6.2 or later for development
• Xcode 26 or later for development

Installation

Using Homebrew (Recommended)

The easiest way to install EventKit MCP Server is via Homebrew:

brew install k3KAW8Pnf7mkmdSMPHz27/mcp/eventkit-mcp-server

This taps k3KAW8Pnf7mkmdSMPHz27/homebrew-mcp automatically and builds from source on your machine (no prebuilt binaries are distributed).

Building from Source

# Clone the repository
git clone https://github.com/k3KAW8Pnf7mkmdSMPHz27/EventKitMCP.git
cd EventKitMCP

# Build the project
swift build -c release

# The executable will be at .build/release/eventkit-mcp-server

Running the Server

# Run directly
swift run eventkit-mcp-server

# Or run the built executable
.build/release/eventkit-mcp-server

# Run in read-only mode (no create/update/delete)
.build/release/eventkit-mcp-server --read-only

# Restrict to specific reminder lists only
.build/release/eventkit-mcp-server --allowed-lists "list-id-1,list-id-2"

Configuration

Claude Desktop

Add this to your Claude Desktop configuration file (~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "eventkit": {
      "command": "/opt/homebrew/bin/eventkit-mcp-server"
    }
  }
}

With list restrictions:

{
  "mcpServers": {
    "eventkit": {
      "command": "/opt/homebrew/bin/eventkit-mcp-server",
      "args": ["--allowed-lists", "list-id-1,list-id-2"]
    }
  }
}

Permissions

The server requires access to Reminders. On first run, macOS will prompt you to grant permission. You can also grant access manually in:

System Settings → Privacy & Security → Reminders

EventKit grants reminder access to the server process. If the prompt was dismissed or denied, enable the terminal or host application that launches the server, then restart it. Location alarms can include precise coordinates and are returned only through this already-authorized Reminders tool surface.

Available Tools

Tool	Description
query_reminders	Query reminders by list, filter (all/overdue/today/upcoming), and regex search; supplied constraints are combined and results are paginated
write_reminders	Create, update, or delete reminders. Uses upsert array (no id = create, with id = update) and delete array for IDs to remove
get_reminder_lists	Get all reminder lists
manage_reminder_list	Create or delete reminder lists (action='create' with title and optional hex color, or action='delete' with id)
overview	Get a concise dashboard: date/timezone, counts, lists, overdue/today/upcoming reminders; the structured output carries the same sections

Tool Examples

Query Reminders

// Get all reminders
{ "name": "query_reminders", "arguments": {} }

// Get overdue reminders
{ "name": "query_reminders", "arguments": { "filter": "overdue" } }

// Get upcoming reminders (next 14 days)
{ "name": "query_reminders", "arguments": { "filter": "upcoming", "days": 14 } }

// Retrieve up to 25 reminders by default; request subsequent pages with offset
{ "name": "query_reminders", "arguments": { "limit": 25, "offset": 25 } }

// Search by regex
{ "name": "query_reminders", "arguments": { "search": "grocery|shopping" } }

// Search within overdue reminders in one list
{
  "name": "query_reminders",
  "arguments": {
    "listId": "list-id",
    "filter": "overdue",
    "search": "invoice|renewal"
  }
}

// Match one or more IDs with the regex search field
{ "name": "query_reminders", "arguments": { "search": "id1|id2" } }

Query responses include count, totalCount, offset, and hasMore so clients can continue without placing the entire reminders database in one model context.

filter defaults to all, and days sets the upcoming window: 1 through 3650, default 7. Completed reminders are left out unless includeDone is true. limit takes 1 through 100 and defaults to 25; offset defaults to 0.

Write Reminders (Create/Update/Delete)

// Create a new reminder (no id in upsert item)
{
  "name": "write_reminders",
  "arguments": {
    "upsert": [{
      "title": "Buy groceries",
      "notes": "Milk, eggs, bread",
      "dueDate": "2024-12-25T10:00:00Z",
      "priority": "high"
    }]
  }
}

// Update existing reminder (include id in upsert item)
{
  "name": "write_reminders",
  "arguments": {
    "upsert": [{
      "id": "reminder-id",
      "done": true
    }]
  }
}

// Delete reminders
{
  "name": "write_reminders",
  "arguments": {
    "delete": ["reminder-id-1", "reminder-id-2"]
  }
}

// Mixed operations in single call
{
  "name": "write_reminders",
  "arguments": {
    "upsert": [
      { "title": "New task" },
      { "id": "existing-id", "done": true }
    ],
    "delete": ["old-task-id"]
  }
}

One call carries at most 100 operations, counting upsert and delete together.

Supported reminder fields

The write and query tools preserve titles, notes, completion state, priority, list, due date, start date, IANA time zones, all-day flags, URL, RFC 5545 recurrence, and relative, absolute, or geofence alarms.

Dates are ISO 8601: with an offset (2026-01-06T10:00:00-06:00), as wall-clock time (2026-01-06T10:00:00), or date-only for an all-day reminder (2026-01-06). dueTimeZone and startTimeZone anchor the wall-clock and date-only forms; without one, the date floats in the Mac's local time. A time-zone key is read only together with its date. EventKit keeps one time zone and one all-day form per reminder, so when the due and start dates disagree, the start date's apply to both. Reminders also gives a timed due date a matching start date, and a start date with no due date loses its time zone.

Marking a recurring reminder done, on create or update, works as in Reminders.app: the current occurrence becomes a separate done reminder, and the reminder moves to its next occurrence.

Updates use three-state patch semantics for nullable fields: omit a property to leave it unchanged, send JSON null to clear it, or send a value to replace it. This applies to notes, dueDate, url, startDate, recurrence, and alarms. URLs must include a scheme, and time zones must be valid IANA identifiers such as America/Chicago. Integer parameters (days, limit, offset, minutesBefore) take JSON integers, so 15.5 is rejected; coordinates and radius take any number.

Alarms use one of these tagged object shapes:

{ "kind": "relative", "minutesBefore": 15 }
{ "kind": "absolute", "absoluteDate": "2026-09-03T17:00:00Z" }
{
  "kind": "location",
  "proximity": "enter",
  "title": "Office",
  "latitude": 41.8781,
  "longitude": -87.6298,
  "radius": 100
}

An absoluteDate without an offset is read in startTimeZone, else dueTimeZone, else the Mac's local time. Relative alarms count back from the due date, so they need one.

A location alarm is what Reminders.app shows as a reminder's location. Reminders keeps no separate location text, so there is no location field.

Manage Lists

// Create a list, optionally with a hex color
{ "name": "manage_reminder_list", "arguments": { "action": "create", "title": "Work", "color": "#FF5733" } }

// Delete a list
{ "name": "manage_reminder_list", "arguments": { "action": "delete", "id": "list-id" } }

Command-Line Options

Flag	Description
--verbose, -v	Enable verbose logging
--log-to-stderr	Send logs to stderr (default: suppressed for MCP)
--read-only	Disable all mutating operations
--allowed-lists <ids>	Comma-separated list IDs to restrict access to
--version	Print the version and exit

With --allowed-lists, a reminder in any other list looks exactly like a missing one, and creating a reminder without listId fails unless the default list is one of the allowed lists. The server refuses to start when none of the IDs match an existing list.

Development

The supported development baseline is Xcode 26 with Swift 6.2 or newer. The runtime deployment target remains macOS 14. Dependencies are pinned in Package.resolved. Debug builds treat warnings as errors; release builds only report them. CI runs the two lints, swift build -c release and swift test, nothing else. SwiftLint is pinned in CI (brew install swiftlint locally); swift format ships with Xcode.

swift build              # Build (warnings are errors)
swift test               # Run tests (what CI runs)
swift build -c release   # Build release (what CI and Homebrew run)

swift format format --in-place --recursive --parallel Sources Tests Package.swift
swift format lint --strict --recursive --parallel Sources Tests Package.swift
swiftlint lint --strict  # size and complexity ceilings; lower them when a maximum shrinks

# Interactive debugging with MCP Inspector
npx @modelcontextprotocol/inspector .build/debug/eventkit-mcp-server

# Verify the read-only surface (query, lists, and overview only)
npx @modelcontextprotocol/inspector .build/debug/eventkit-mcp-server --read-only

Releases

Every merge to main is squashed, so the PR title becomes the commit subject, and titles must be conventional commits. When CI passes on main, semantic-release tags a new version from the commits since the last tag and publishes a GitHub Release with generated notes:

Title	Release
feat: ...	minor
fix: ..., perf: ..., revert: ...	patch
feat!: ..., or a BREAKING CHANGE: footer	major
docs:, ci:, chore:, refactor:, test:, ...	none

The version string in the source is a placeholder; Homebrew builds write the tag's version into it.

License

See LICENSE for details.