@cyanheads/macos-mcp-server

@cyanheads/macos-mcp-server

Control macOS system settings, apps, windows, audio, displays, screenshots, and Focus mode via MCP. STDIO or Streamable HTTP.

13 Tools • 3 Resources

macOS-only. This server controls the local macOS system — it requires the host machine to be running macOS. HTTP transport is supported for completeness, but the practical use case is stdio: run it locally and point your MCP client at it.

Tools

13 tools covering macOS system state, app and window management, audio routing, display control, screenshots, Finder integration, notifications, and Focus mode:

Tool	Description
macos_get_info	System snapshot: battery level and charging status, power source, Wi-Fi SSID, hostname, macOS version, uptime, and display count
macos_check_permissions	Reports Accessibility, Screen Recording, Automation > Finder, and Notification status for the calling process
macos_manage_apps	List, launch, quit, force-quit, hide, or show applications
macos_manage_windows	List, focus, move, resize, move_resize, minimize, fullscreen, or close windows
macos_control_volume	Get or set system output volume (0–100) and mute state
macos_control_audio	List audio devices, get current defaults, or switch the default input/output device
macos_control_appearance	Get or set dark/light mode
macos_control_system	Lock the screen or put the display to sleep
macos_take_screenshot	Capture full screen, display, named app window, or pixel region; saves PNG; optional base64 JPEG preview
macos_manage_displays	List connected displays and apply named display layout presets
macos_send_notification	Post a notification to macOS Notification Center
macos_manage_focus	Get or set Do Not Disturb / Focus mode
macos_manage_finder	Frontmost path, current selection, reveal, open with app, or move to Trash

macos_get_info

Returns a live system snapshot with no prerequisites.

• Battery level (0–100), charging state, and power source (AC, Battery, UPS); null on desktops with no battery
• Wi-Fi connection status and SSID
• Hostname, macOS version string (e.g. "15.1.0"), uptime in seconds
• Connected display count

macos_check_permissions

Reports permission status for each capability this server exercises. Run this first when debugging why a tool is failing.

• Accessibility — required for window manipulation (move, resize, minimize, fullscreen, close), app hide/show
• Screen Recording — required for window screenshots (macos_take_screenshot with target=window)
• Automation > Finder — required for macos_manage_finder with action=get_selection
• Notifications — always granted (osascript notifications bypass Do Not Disturb)
• Returns the name of the calling process (e.g. "ghostty", "node") so you know which process to grant permissions for

macos_manage_apps

Manage the lifecycle of user-facing applications.

• list — all running user-facing apps with name, bundle ID, PID, visible, and frontmost flags
• frontmost — name, bundle ID, PID, and frontmost window title of the active app
• launch — open or activate an app by name or bundle ID; hidden=true starts in the background
• quit — graceful quit via AppleScript tell application … to quit
• force_quit — SIGKILL without saving
• hide / show — toggle app visibility; requires Accessibility

macos_manage_windows

Window operations across all visible apps via System Events Accessibility.

• list — all visible windows with app name, title, position, size, minimized state, and display index (0 = primary)
• focus — bring an app or window to the foreground (does not require Accessibility)
• move — reposition a window by top-left coordinate
• resize — change a window's width and height
• move_resize — set position and size in one call
• minimize — minimize to Dock or restore; minimized=true to minimize, false to restore
• fullscreen — toggle fullscreen via ⌃⌘F keystroke
• close — click the close button via Accessibility
• Target by app_name, window_title, or both (window_title takes precedence)
• All mutating actions (everything except list and focus) require Accessibility

macos_control_volume

• get — returns current output volume (0–100) and mute state
• set — accepts level (0–100), muted (true/false), or both; setting level=0 does not mute
• Always returns current state after a set

macos_control_audio

Audio device routing via SwitchAudioSource CLI (brew install switchaudio-osx).

• list — all input and output devices, with is_default flag; filter by type=input|output|all
• current — current default input and output device names
• switch_output / switch_input — change the default device; supports case-insensitive partial name matching ("MacBook" matches "MacBook Pro Microphone")
• Volume level control is separate (macos_control_volume)

macos_control_appearance

• get — returns dark_mode: true/false
• set with mode=dark|light|toggle — dark/light are idempotent; toggle flips on each call

macos_control_system

• lock — locks the screen immediately via ⌃⌘Q (Accessibility); falls back to ScreenSaverEngine binary if Accessibility is not granted
• sleep_display — puts all displays to sleep via pmset displaysleepnow; no permissions required

macos_take_screenshot

Saves a full-resolution PNG to disk; optionally returns a downscaled JPEG preview as base64.

• screen — full screen capture (all displays merged); no Screen Recording required
• display — a specific display by 0-based display_index; no Screen Recording required
• window — a named app window by app_name; requires Screen Recording
• region — a pixel rectangle { x, y, width, height }; no Screen Recording required
• path — custom output path (must be within ~/Desktop, /tmp, or home dir); defaults to MACOS_SCREENSHOT_DIR/<timestamp>.png (falls back to ~/Desktop)
• include_data=true — adds preview (base64 JPEG, max 1024px wide, ~70% quality) + preview_width / preview_height to the response for agent visual analysis

macos_manage_displays

Requires displayplacer CLI (brew install jakehilborn/jakehilborn/displayplacer).

• list — connected display inventory: persistent ID, connection type, resolution, refresh rate, origin, rotation, scaling, enabled state; plus current_config (a displayplacer command string that reproduces the active arrangement)
• apply_layout — activates a named preset from MACOS_DISPLAY_LAYOUTS; layout names are pre-configured in the env var — raw displayplacer args are never accepted from the user

macos_send_notification

Posts to Notification Center via osascript. Does not require notification permission — osascript notifications bypass Do Not Disturb.

• title (required), body, subtitle, sound=true (plays default notification sound)
• Each call creates a new notification; not idempotent

macos_manage_focus

• get — best-effort: reads ~/Library/DoNotDisturb/DB/Assertions.json when accessible; returns status: active|inactive|unknown; unknown is expected on macOS 13+ where the database is SIP-protected
• set — requires the built-in "Set Focus" shortcut to exist in Shortcuts.app (present by default on macOS 12+); mode must match a configured Focus profile exactly (e.g. "Do Not Disturb", "Work"); enabled defaults to true

macos_manage_finder

Finder integration via osascript and open.

• frontmost_path — POSIX path of the active Finder window, or null when no window is open; no permissions required
• get_selection — POSIX paths of selected items; requires Automation > Finder permission
• reveal — highlight a path in Finder (open -R path)
• open_with — open a path with a named app (open -a AppName path)
• trash — moves a path to the Trash (recoverable); not a permanent delete

Resources

Type	Name	Description
Resource	macos://system/info	Current macOS system snapshot: battery, power source, Wi-Fi SSID, hostname, version, uptime, display count
Resource	macos://audio/devices	All audio input and output devices, including which is the current default. Requires SwitchAudioSource CLI.
Resource	macos://displays	Connected display inventory including persistent IDs, type, resolution, origin, rotation, scaling, and enabled state. Requires displayplacer CLI.

Resource data is also accessible via macos_get_info, macos_control_audio (action=list), and macos_manage_displays (action=list).

Features

Built on @cyanheads/mcp-ts-core:

• Declarative tool and resource definitions — single file per primitive, framework handles registration and validation
• Unified error handling — handlers throw, framework catches, classifies, and formats with structured recovery hints
• Structured logging with optional OpenTelemetry tracing
• STDIO and Streamable HTTP transports

macOS-specific:

• osascript service with configurable timeout — wraps both JXA (runJxa) and AppleScript (runAppleScript)
• SwitchAudioSource integration for audio device routing (optional dependency — graceful error when absent)
• displayplacer integration for display management and layout presets (optional dependency — graceful error when absent)
• screencapture + sips pipeline for PNG capture and JPEG preview generation
• system_profiler, pmset, and networksetup for hardware state
• Permission-first design — macos_check_permissions tells you exactly which process needs which permission before you hit a Forbidden error

Agent-friendly output:

• Permission errors include specific grant instructions (System Settings > Privacy & Security > [permission type])
• Optional CLI tools (SwitchAudioSource, displayplacer) surface ServiceUnavailable with install instructions (brew install …)
• macos_manage_windows action=list includes display_index on every window so agents can reason about multi-monitor layouts
• macos_take_screenshot separates full-resolution disk write from optional base64 preview — keeps response size manageable

Getting started

This server is local-only — it controls the macOS system it runs on. Use STDIO transport with your MCP client.

Add the following to your MCP client configuration file:

{
  "mcpServers": {
    "macos-mcp-server": {
      "type": "stdio",
      "command": "bunx",
      "args": ["@cyanheads/macos-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with npx (no Bun required):

{
  "mcpServers": {
    "macos-mcp-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@cyanheads/macos-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Prerequisites

• macOS 12 (Monterey) or higher.
• Bun v1.3.0 or higher (or Node.js v24+).
• Optional: SwitchAudioSource for audio routing (brew install switchaudio-osx).
• Optional: displayplacer for display management (brew install jakehilborn/jakehilborn/displayplacer).

Some tools require macOS permissions granted to the terminal or MCP host app:

Permission	Required by
Accessibility	macos_manage_windows (mutating actions), macos_manage_apps (hide/show), macos_control_system (lock)
Screen Recording	macos_take_screenshot with target=window
Automation > Finder	macos_manage_finder with action=get_selection

Use macos_check_permissions to check current status before running permission-gated operations.

Installation

• Clone the repository:

git clone https://github.com/cyanheads/macos-mcp-server.git

• Navigate into the directory:

cd macos-mcp-server

• Install dependencies:

bun install

• Configure environment:

cp .env.example .env
# edit .env if you want to set MACOS_SCREENSHOT_DIR or MACOS_DISPLAY_LAYOUTS

Configuration

Variable	Description	Default
MACOS_SCREENSHOT_DIR	Default directory for screenshot files.	~/Desktop
MACOS_DISPLAY_LAYOUTS	JSON object mapping layout names to displayplacer argument strings. Used by macos_manage_displays action=apply_layout.	{}
MCP_TRANSPORT_TYPE	Transport: stdio or http.	stdio
MCP_HTTP_PORT	Port for HTTP server.	3010
MCP_AUTH_MODE	Auth mode: none, jwt, or oauth.	none
MCP_LOG_LEVEL	Log level.	info
OTEL_ENABLED	Enable OpenTelemetry instrumentation.	false

See .env.example for the full list of optional overrides.

Display layout example:

# Get the current displayplacer command for your setup:
displayplacer list

# Then configure named layouts in your env:
MACOS_DISPLAY_LAYOUTS='{"office":"id:1234 res:2560x1440 hz:60 color_depth:8 scaling:on origin:(0,0) degree:0 id:5678 res:1920x1080 hz:60 color_depth:8 scaling:on origin:(2560,0) degree:0"}'

Running the server

Local development

# One-time build
bun run rebuild

# Run the built server
bun run start:stdio

# Run checks
bun run devcheck   # Lint, format, typecheck, security, changelog sync
bun run test       # Vitest test suite
bun run lint:mcp   # Validate MCP definitions against spec

Docker

docker build -t macos-mcp-server .
docker run --rm -p 3010:3010 macos-mcp-server

The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/macos-mcp-server. Note: the Docker image cannot exercise osascript or system CLI tools — it is provided for completeness but has limited utility for this server.

Project structure

Path	Purpose
src/index.ts	createApp() entry — registers tools/resources and inits services
src/config/server-config.ts	MACOS_SCREENSHOT_DIR and MACOS_DISPLAY_LAYOUTS env parsing
src/mcp-server/tools/definitions/	13 tool definitions (macos-*.tool.ts)
src/mcp-server/resources/definitions/	3 resource definitions (macos-*.resource.ts)
src/services/osascript/	osascript JXA + AppleScript runner with configurable timeout
src/services/audio/	SwitchAudioSource device listing and switching
src/services/display/	displayplacer list and apply-layout
src/services/screencapture/	screencapture + sips PNG capture and JPEG preview
src/services/system-info/	Battery, Wi-Fi, hostname, uptime via system_profiler/pmset
tests/tools/	Tool tests mirroring definitions

Development guide

See CLAUDE.md for development guidelines and architectural rules. The short version:

• Handlers throw, framework catches — no try/catch in tool logic
• Use ctx.log for request-scoped logging; no console calls
• All tool names are prefixed macos_ and use snake_case; file names are macos-*.tool.ts
• Services are singletons initialized in createApp() and accessed via get*Service() accessors

Contributing

Issues and pull requests are welcome. Run checks and tests before submitting:

bun run devcheck
bun run test

License

Apache-2.0 — see LICENSE for details.