Osa

Give your AI access to every scriptable app on your Mac.

osa-mcp is an MCP server that automatically discovers all scriptable macOS apps (Mail, Calendar, Finder, Music, Notes, Safari, &c.) and generates tools for them. No configuration, no hardcoded app list. Just connect and go.

What you do

npx

claude mcp add my-mac -- npx -y osa-mcp

bunx

claude mcp add my-mac -- bunx osa-mcp

Homebrew

brew install MayCXC/osa-mcp/osa-mcp
claude mcp add my-mac -- osa-mcp

Remote Mac via SSH

If your AI runs on a different machine, connect to your Mac over SSH. Enable Remote Login in System Settings > General > Sharing first.

claude mcp add my-mac -- npx -y osa-mcp --ssh [email protected]

JSON config

All of the above can also be added to your MCP settings file directly:

{
  "mcpServers": {
    "my-mac": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "osa-mcp"]
    }
  }
}

For SSH, add "--ssh", "[email protected]" to the args.

What you get

On a typical Mac, osa-mcp generates ~700 tools in ~4 seconds. Every tool includes descriptions pulled from the app's scripting dictionary, so your AI knows what each tool does, what parameters it takes, and what values they accept.

Commands let your AI perform actions:

• mail_send, mail_reply, mail_forward
• finder_reveal, finder_move, finder_duplicate
• music_play, music_pause, music_search
• calendar_show, reminders_show, notes_show
• safari_do_javascript, safari_search_the_web
• messages_send, terminal_do_script

Lists and gets let your AI read data:

• mail_list_messages, mail_get_message
• calendar_list_events, calendar_list_calendars
• finder_list_files, finder_list_disks
• notes_list_notes, reminders_list_reminders
• safari_list_tabs, safari_list_documents

Application properties expose app settings:

• mail_get_application returns inbox, fetch interval, primary email, etc.
• finder_get_application returns desktop, trash, home, startup disk, etc.
• music_get_application returns current track, player state, etc.

Execute runs arbitrary AppleScript or JXA for anything the generated tools don't cover.

Navigating the object hierarchy

Many tools accept a parent parameter for navigating into nested objects:

// List events in a specific calendar
{ "parent": ["calendars", "byName", ["Work"]] }

// List messages in the inbox
{ "parent": ["inbox"] }

// Get the first window's current tab
{ "parent": ["windows", 0] }

Path steps: "key" accesses a property, 0 accesses by index, [] calls a method, ["arg"] calls with arguments.

Install from source

git clone https://github.com/MayCXC/osa-mcp.git
cd osa-mcp
bun install
bun link
claude mcp add my-mac -- osa-mcp

Requires Bun.

License

BSD 3-Clause. See LICENSE.