mcp-osascript

Quick Start

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

Add this to your Claude Desktop config (`Settings → Developer → Edit Config`), restart Claude, and you're ready.

Config for other clients (Cursor, VS Code, Claude Code)

Cursor / VS Code (Copilot)

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

Claude Code

claude mcp add osascript -- npx -y mcp-osascript

From source (development)

git clone https://github.com/m0rvayne/mcp-osascript.git
cd mcp-osascript && npm install
# then use: "command": "node", "args": ["/path/to/mcp-osascript/server/index.js"]

Try These Prompts

Once installed, ask Claude:

Tools

12 typed tools, each with input validation, error classification, and permission-aware error messages.

Self-Correcting Menus

When Claude tries to click a menu item that doesn't exist, the server automatically returns the list of available items at that level — so Claude can retry with the correct name. No other MCP server does this.

User:   "Click File → Export as PDF in Preview"
Claude: calls app_menu click ["File", "Export as PDF"]
Server: "Menu item 'Export as PDF' not found in 'File'.
         Available: ['New from Clipboard', 'Open...', 'Close', 'Save',
         'Duplicate', 'Rename...', 'Export...', 'Export as PDF...']"
Claude: calls app_menu click ["File", "Export as PDF..."]
Server: "Clicked: File > Export as PDF..."

Why mcp-osascript?

Permissions

Tools work in three tiers:

• No permission needed — clipboard, notifications, URLs, apps. Works immediately.
• Automation — browser tabs, frontmost app. macOS prompts once per browser.
• Accessibility — keyboard, windows, menus. Grant once in System Settings → Privacy & Security → Accessibility.

When a permission is missing, the server tells you exactly what to do:

"Accessibility permission required. Grant access to 'osascript'
in System Settings > Privacy & Security > Accessibility."

Testing

npm test

41 integration tests covering all 12 tools — input validation, security boundaries (URL scheme blocking, prototype pollution, script size limits), timeout enforcement, and permission error handling.

Security & Architecture

Security

• `run_osascript` executes arbitrary code — this is by design. The MCP client (Claude) is the trust boundary.
• Scripts piped via stdin to `/usr/bin/osascript` — no temp files, no TOCTOU race conditions.
• Script size: 50 KB max. Output: 50K chars max (truncated).
• Error messages sanitized — filesystem paths, tokens, and passwords are stripped.
• Child processes get minimal env: `PATH`, `HOME`, `LANG` only — no API keys or secrets leak.
• URL scheme allowlist — `file://`, `smb://`, `vnc://`, `javascript:` all blocked.
• Handler dispatch uses `Object.create(null)` — no prototype pollution.

Reliability

• Process group kill on timeout — SIGTERM → 2s grace → SIGKILL. No orphaned processes.
• Concurrency semaphore — max 5 simultaneous osascript processes.
• Graceful shutdown — `server.close()` with 10s force-exit safety net.
• Error classification — parses macOS error codes (-1728, -1743, -25211) into actionable messages. Supports English and Russian locales.

Requirements

• macOS 13+ (Ventura or later)
• Node.js 18+

License

MIT