macos-mcp

Based on FradSer/mcp-server-apple-events

MCP server for Reminders, Calendar, Notes, Mail, Messages, and Contacts on macOS. Local stdio transport — works with any MCP-capable client running on the same Mac (Claude Code, Claude Desktop, Cursor, Zed, Continue, ChatGPT desktop, etc.).

Requires a Mac. This server drives native macOS apps via EventKit, JXA (Apple Events), and SQLite reads of local Apple databases. It cannot run on Linux, Windows, iOS, Android, or in a web browser. You need a Mac (desktop or laptop) running macOS.

Design Notes

• SQLite for reads, JXA for writes. JXA reads of Mail and Messages don't scale — 60s timeouts on real inboxes, and JXA Messages reads are broken entirely on macOS Sonoma+. This server reads chat.db and Mail's Envelope Index directly, including the Gmail labels join table for [Gmail]/All Mail accounts. Writes still go through JXA because Apple Events is the only API that triggers them. See ADR-001.
• Per-app hybrid backend. Each app uses the bridge that works: Swift CLI through EventKit for Reminders and Calendar, JXA for Notes/Contacts/Mail-writes/Messages-send, SQLite for Mail and Messages reads. The architecture diagram below shows the full fan-out.
• Cross-tool contact enrichment. A shared layer resolves raw phone numbers and emails to contact names across Messages, Mail, and Calendar. Bulk cache via SQLite AddressBook (<50ms for 1,100+ entries), targeted lookups via JXA whose(). See ADR-002.
• Preflight check. macos-mcp --check validates macOS version, Node.js, the EventKit binary, Full Disk Access, and JXA permissions before runtime, with deep-links to the relevant System Settings panes for any failures.

Quick Start

Install as a Claude Code plugin

/plugin marketplace add krmj22/macos-mcp
/plugin install macos-mcp@krmj22-plugins

Run these inside Claude Code. The plugin wires up the MCP server via npx -y mcp-macos, so no separate install step is required.

Install from npm

npm install -g mcp-macos
# or use npx via your client's MCP config (no global install needed)

Or install via MCPB (Claude Desktop)

Download the .mcpb bundle from the latest GitHub release and drag it onto Claude Desktop. The bundle includes a pre-built universal Swift binary (arm64 + x86_64), so no Xcode Command Line Tools required.

Or build from source

git clone https://github.com/krmj22/macos-mcp.git
cd macos-mcp
pnpm install
pnpm build

Verify setup

macos-mcp --check   # or: node dist/index.js --check

Checks macOS version, Node.js, EventKit binary, Full Disk Access, and JXA automation permissions.

Tools

Tool	App	Bridge	Actions
reminders_tasks	Reminders	EventKit	read, create, update, delete
reminders_lists	Reminders	EventKit	read, create, update, delete
calendar_events	Calendar	EventKit	read, create, update, delete
calendar_calendars	Calendar	EventKit	read
notes_items	Notes	JXA	read, create, update, delete
notes_folders	Notes	JXA	read, create
mail_messages	Mail	SQLite + JXA	read, create, update, delete
messages_chat	Messages	SQLite + JXA	read, create
contacts_people	Contacts	JXA	read, search, create, update, delete

Both underscore (reminders_tasks) and dot (reminders.tasks) notation work.

Setup

Prerequisites

• Node.js 20+
• macOS
• Xcode Command Line Tools (Swift compilation)

Client Configuration

The JSON config is the same for all clients — just the location differs.

{
  "mcpServers": {
    "macos-mcp": {
      "command": "npx",
      "args": ["mcp-macos"]
    }
  }
}

Client	Config location
Claude Desktop	claude_desktop_config.json
Cursor	Settings > MCP > Add new global MCP server
Claude Code	.mcp.json in project root

Permissions

macOS prompts for access on first use. Click Allow when prompted.

App	Permission	System Settings Path
Reminders	Full Access	Privacy & Security > Reminders
Calendar	Full Access	Privacy & Security > Calendars
Notes	Automation	Privacy & Security > Automation > Notes
Mail	Automation + Full Disk Access	Both locations
Messages	Automation + Full Disk Access	Both locations
Contacts	Automation	Privacy & Security > Automation > Contacts

Messages and Mail read SQLite databases directly, so your terminal app (Terminal, iTerm2, etc.) needs Full Disk Access.

Run macos-mcp --check to verify. See Troubleshooting if anything fails.

Troubleshooting

Quick-Fix Commands

# Open specific settings panes
open "x-apple.systempreferences:com.apple.preference.security?Privacy_Reminders"
open "x-apple.systempreferences:com.apple.preference.security?Privacy_Calendars"
open "x-apple.systempreferences:com.apple.preference.security?Privacy_Automation"
open "x-apple.systempreferences:com.apple.preference.security?Privacy_AllFiles"

Full Disk Access (Messages & Mail)

Messages and Mail read SQLite databases (~/Library/Messages/chat.db and ~/Library/Mail/V10/MailData/Envelope Index). These require Full Disk Access on your terminal app.

# Find your real node binary (version managers use shims)
node -e "console.log(process.execPath)"

# Reveal it in Finder for drag-and-drop into FDA settings
open -R "$(node -e "console.log(process.execPath)")"

# Open Full Disk Access settings
open "x-apple.systempreferences:com.apple.preference.security?Privacy_AllFiles"

Version manager users (Volta, nvm, fnm): the node command is a shim. System Settings needs the real binary:

Manager	Find real binary
Volta	volta which node
nvm	nvm which current
fnm	fnm exec -- node -e "console.log(process.execPath)"

System Settings may not show binaries in hidden directories — use open -R above to reveal it in Finder, then drag into the FDA list.

JXA Automation (Notes, Mail, Contacts)

On first use, macOS prompts for Automation access. Grant via System Settings > Privacy & Security > Automation.

Verify permissions:

osascript -l JavaScript -e 'Application("Contacts").people().length'
osascript -l JavaScript -e 'Application("Calendar").calendars().length'
osascript -l JavaScript -e 'Application("Reminders").defaultList().name()'
osascript -l JavaScript -e 'Application("Mail").inbox().messages().length'
osascript -l JavaScript -e 'Application("Notes").notes().length'

Each command should return a value. A hang means the permission dialog is trying (and failing) to appear.

Gmail Labels / Missing Inbox Messages

Gmail stores all messages in [Gmail]/All Mail and uses labels for folder membership. The server checks both the direct mailbox and labels join table. If Gmail inbox messages are missing, verify the Mail app has fully synced.

Development

pnpm install          # Install dependencies
pnpm build            # Build TypeScript + Swift binary
pnpm test             # Run full test suite
pnpm lint             # Lint and format (Biome + TypeScript)
pnpm dev              # Run from source via tsx

Production entry point (bin/run.cjs) requires pnpm build. Use pnpm dev for local development.

Architecture

flowchart LR
    Client[MCP Client<br/>Claude Code, Cursor, Desktop] -->|stdio| Server[macos-mcp]

    Server --> Swift[Swift CLI]
    Server --> JXA[JXA]
    Server --> SQLite[SQLite Readers]

    Swift -->|EventKit| Reminders[Reminders]
    Swift -->|EventKit| Calendar[Calendar]

    JXA -->|Apple Events| Notes[Notes]
    JXA -->|Apple Events| Contacts[Contacts]
    JXA -->|writes only| Mail[Mail]
    JXA -->|send only| Messages[Messages]

    SQLite -->|Envelope Index| Mail
    SQLite -->|chat.db| Messages
    SQLite -->|AddressBook| Enrich[Contact<br/>Enrichment Cache]

Three bridges to Apple apps:

• EventKit (Swift binary) — Reminders, Calendar. Compiled Swift CLI, returns JSON.
• JXA — Notes, Mail writes, Contacts. Scripts run via osascript -l JavaScript.
• SQLite — Messages reads (~/Library/Messages/chat.db), Mail reads (~/Library/Mail/V10/MailData/Envelope Index). JXA message reading is broken on Sonoma+; JXA mail reading is too slow for real inboxes.

Mail and Messages use a hybrid path: JXA for writes (only way to trigger send/draft), SQLite for reads (the only way that scales). See DECISION.md for architecture decision records.

Dependencies

Runtime: @modelcontextprotocol/sdk, zod

Dev: typescript, tsx, jest, @biomejs/biome

License

MIT

Contributing

See CONTRIBUTING.md.