Macbot

An MCP server that gives AI agents hands on macOS — via the Accessibility API, AppleScript, and Quartz CGEvents.

The macOS counterpart to ahk-mcp. Same thesis: the accessibility tree already contains a machine-readable description of everything on screen. Screenshots throw that away and make the model re-derive it from pixels. Why?

Token cost per action: ~200-700 tokens (vs ~2000-3500 for screenshot-based).

Because the output is structured text, not images, any language model can drive it — including small open-source models with no vision capability. A 7B model can parse AXButton title="Save" @450,320 88x32 and call mac_click(x=490, y=336). It cannot interpret a screenshot. The accessibility approach makes computer use available to models that were previously locked out of it entirely.

How it works

macbot-mcp exposes 14 tools over MCP's stdio transport:

• Observation tools read the macOS accessibility tree, window properties, and browser URLs — returning structured text with element roles, names, values, and screen coordinates
• Action tools click, drag, scroll, type, and send keystrokes via Quartz CGEvents and AppleScript
• mac_run_applescript is the escape hatch — execute arbitrary AppleScript for anything the built-in tools don't cover

Every observation tool returns coordinates. Find a button with mac_ui_find, get its x,y position, and click it with mac_click — no screenshot needed.

Token cost comparison

Approach	Tokens per action	What you get
Screenshot-based (full screen PNG)	~2000-3500	Pixels. Model must OCR, locate elements, interpret layout.
macbot-mcp (structured text)	~200-700	Element roles, titles, values, and pixel coordinates.

A 20-step workflow: ~50k tokens with screenshots, ~8k with macbot. The structured output is also more reliable — the model doesn't guess where the "Save" button is when the accessibility tree says AXButton title="Save" @1043,672 88x32.

Installation

Prerequisites

• macOS 12+ (Monterey or later)
• Python 3.10+

Setup

git clone https://github.com/anomalous3/macbot-mcp.git
cd macbot-mcp

# Create a virtual environment
python3 -m venv .venv
# or: uv venv .venv

# Activate
source .venv/bin/activate

# Install dependencies
pip install -r requirements.txt

macOS Permissions

macbot needs two permissions, granted to your terminal app (Terminal, kitty, iTerm2, etc.):

1. Accessibility — System Settings > Privacy & Security > Accessibility
2. Screen Recording — System Settings > Privacy & Security > Screen Recording

Without Accessibility, observation and input tools won't work. Without Screen Recording, mac_screenshot will fail.

Claude Code MCP configuration

Add to your ~/.claude.json:

{
  "mcpServers": {
    "macbot": {
      "command": "/path/to/macbot-mcp/.venv/bin/python3",
      "args": ["/path/to/macbot-mcp/server.py"],
      "env": {
        "MACBOT_SCREENSHOT_DIR": "/tmp/macbot"
      }
    }
  }
}

After adding the config, restart Claude Code. The tools appear with the mcp__macbot__ prefix.

Tool reference

Observation

Tool	Description
mac_ui_tree	Dump the accessibility tree of any app. Returns roles, titles, values, descriptions, and screen coordinates. Configurable depth and node limit. This is the primary observation tool — use it before reaching for screenshots.
mac_ui_find	Search for UI elements by name and/or role. Returns matches with coordinates. Find that "Submit" button without scanning the whole tree.
mac_ui_url	Get the current URL from the active browser's address bar (Firefox, Chrome, Safari).
mac_get_windows	List all visible windows with app name, title, position, and size.
mac_screenshot	Capture full screen, a specific window, or a region. Returns a PNG file path. The fallback when you genuinely need pixels.

Action

Tool	Description
mac_click	Click at screen coordinates. Uses Quartz CGEvents (falls back to cliclick if installed).
mac_drag	Click and drag between two points. Configurable duration for smooth drags. Works for rotating 3D plots, selecting text, moving windows.
mac_scroll	Scroll at a screen position. Vertical and horizontal.
mac_type_text	Type text into the frontmost app. Uses clipboard paste by default (fast, Unicode-safe). Optional keystroke mode for modifier-sensitive fields.
mac_key_press	Send a key press with modifiers. Supports named keys (return, tab, escape, arrows, F-keys) and characters with command/option/control/shift.
mac_focus_app	Bring an application to the front.
mac_get_clipboard	Read the system clipboard.
mac_set_clipboard	Set the system clipboard.

Escape hatch

Tool	Description
mac_run_applescript	Execute arbitrary AppleScript. Full access to System Events, app scripting dictionaries, and everything else AppleScript can do.

Browser automation via the Accessibility API

Modern browsers expose their full UI through the macOS Accessibility API. macbot reads this directly — no browser extension, no WebDriver, no Playwright needed.

Read the tab bar with element coordinates:

> mac_ui_tree app="Firefox" max_depth=5 max_nodes=50

AXApplication title="Firefox"
  AXWindow title="GitHub - anomalous3/macbot-mcp" @36,30 1752x957
    AXGroup desc="GitHub - anomalous3/macbot-mcp" @36,30 1752x957
      AXToolbar desc="Browser tabs" @36,30 1752x44
        AXTabGroup (tab group) @190,30 1518x44
          AXRadioButton title="GitHub - anomalous3/macbot-mcp" value="True" @193,30 210x44
          AXRadioButton title="New Tab" @403,30 210x44

Find a specific element and get its click coordinates:

> mac_ui_find app="Firefox" name="Submit" role="AXButton"

[{"role": "AXButton", "title": "Submit", "x": 450, "y": 320, "width": 80, "height": 32}]

Get the URL without screenshots or clipboard tricks:

> mac_ui_url app="Firefox"

{"url": "https://github.com/anomalous3/macbot-mcp", "field": "Search with Google or enter address"}

Use Firefox. It exposes the richest accessibility tree of the major browsers — more element detail, better labeling, and more consistent structure than Chrome or Safari.

The coordinate system

All coordinates are absolute screen pixels in macOS logical coordinates (not Retina physical pixels). Origin (0,0) is the top-left of the primary display.

The @x,y WxH format in mac_ui_tree output gives position and size directly. To click the center of @450,320 80x32, click at (490, 336).

Works with everything

macbot works with any macOS application that implements the Accessibility API (which is most of them):

• Browsers — Firefox, Chrome, Safari (Firefox recommended for richest tree)
• Terminals — kitty, Terminal.app, iTerm2 (can read content, type commands)
• Editors — VS Code, Sublime Text, TextEdit
• System apps — Finder, System Settings, Activity Monitor
• Any app — if it has windows and controls, macbot can probably read and drive it

Configuration

Variable	Default	Description
MACBOT_SCREENSHOT_DIR	/tmp/macbot	Directory for screenshot PNGs

Platform

macOS only. For Windows, see ahk-mcp. The approach is the same — read the accessibility tree, act via synthetic input — just different platform APIs.

License

MIT