Keyhac 2

Python-scriptable keyboard customization for Windows and macOS.

Keyhac installs a system-wide keyboard hook and lets you script what your keys do in
Python. You write one file, ~/.keyhac/config.py, and it runs unchanged on both OSes —
remapping keys, binding keys to Python functions, and driving windows, applications and
the clipboard from the keyboard.

It can also write the harder scripts for you. Connect an AI assistant and it reads the
screen in front of you, generates a plain-Python action against the real UI, and tests
it — then the action runs on its own, with no AI in the loop.

Keyhac 2 replaces the two previous-generation products, Keyhac for Windows (1.x)
and Keyhac for macOS (1.x), rebuilt as one shared codebase. Those older versions
are no longer developed — if you are coming from one of them, see the migration
guides in Documentation below.
Keyhac 2's UI is built on PuiKit.

Features

Key remapping: key → key, key → key sequence, key → Python function.
Per-application key tables: match by app name, window title, Win32 window class,
or the full accessibility focus path (AX on macOS, UI Automation on Windows) — down to
"only in this app's text editor pane".
User modifiers: turn any key into a modifier of your own (User0–User3), invisible
to applications.
One-shot modifiers: tap a modifier alone for one action, hold it to modify.
Multi-stroke key tables: Emacs-style prefix keys, with a balloon showing the
armed prefix.
Clipboard history: persistent history in a popup chooser — type to filter,
Enter pastes into the app you came from, with its formatting, image or files;
Option/Alt-Enter pastes plain text. Plus fixed snippets and scriptable
clipboard-transform tools.
Window control: move, snap/tile, minimize, activate and launch applications,
multi-monitor aware.
Keyboard macros: record and replay keys.
Mouse output: send clicks, wheel scrolls and pointer moves from key bindings.
Extra Python libraries: list them in ~/.keyhac/requirements.txt and choose
Advanced > Sync Python Packages in the tray menu — the app bundles included.
Console window: live log, last-key and focus-path inspector — see exactly what to
bind. Runs from the system tray (Windows) / menu-bar extra (macOS).
AI-authored actions: let an AI assistant read the screen and write the automation
for you, then bind it to a key — see AI integration below.

AI integration

Keyhac can be driven by an AI assistant while you write your automation, and by
nothing but Python once you run it.

Connect Claude Desktop — or any MCP client — to Keyhac's local endpoint, and it can read
the accessibility tree of the application in front of you, write an Action against the
real element names it finds there, run it, read its own traceback, and fix it. No
copy-pasting between a chat window and an editor. What you are left with is an ordinary
Python class on a key:

import translate_clipboard

def configure(keymap):
    kt = keymap.define_keytable(focus_path_pattern="*")
    kt["Fn-T"] = translate_clipboard.TranslateClipboard()

From then on it runs in milliseconds, offline, with no tokens and no model — the AI was
the author, not the runtime. That matters most for applications with no API at all:
walking pagination to the end, filling a form from each row of a CSV, reading tables out
of an internal web app, capturing every settings screen to JSON.

It is off unless you turn it on — a checkbox in the console window. The endpoint
listens on loopback only, behind a token generated at startup, and closes itself an hour
after you open it.

AI integration covers setup, which clients have been tried,
what it can reach, and the security model.

Screenshots

Console (macOS)	Console (Windows)

Menu-bar extra (macOS)	Task tray (Windows)

Install

macOS 12+ — download Keyhac-<version>-macos.dmg from
Releases: drag Keyhac.app into
Applications and launch it. Or install it with Homebrew:
brew install --cask crftwr/tap/keyhac. Grant the Accessibility permission
when prompted (required for the keyboard hook).
Windows 10/11 (x64) — install from the
Microsoft Store
(or winget install --id 9P8H1PG6PRHH --source msstore) — automatic updates, no
SmartScreen warning. Alternatively, download Keyhac-<version>-win64.zip from
Releases, unzip anywhere and run
Keyhac.exe.

Details, data locations and privacy notes: doc/installation.md.

Quick start

On first run Keyhac creates ~/.keyhac/config.py from a fully commented template.
Open it from the tray / menu-bar icon ("Edit Config"), edit, then "Reload Config".
A config defines one function:

from keyhac import *

def configure(keymap):
    kt = keymap.define_keytable(focus_path_pattern="*")   # active everywhere

    kt["Fn-J"] = "Left"                        # key -> key
    kt["Fn-A"] = "Home", "Shift-End"           # key -> sequence

    def hello():                               # key -> Python function
        print("Hello from config.py")
    kt["Fn-H"] = hello

    kt["Fn-V"] = ShowClipboardHistory()        # clipboard history popup

    kt_browser = keymap.define_keytable(app="chrome|Safari")   # per-app table
    kt_browser["Fn-R"] = "Cmd-R"

The full guide is doc/configuration.md, the per-symbol
reference doc/config-api.md; the shipped template
(keyhac/_config.py) is a working tour of every feature.

Documentation

Installation — install, permissions, data files, privacy.
Configuration — the complete config.py guide.
API reference — every class and function a config.py
can reach, with its exact arguments.
AI integration — connect an MCP client, what the endpoint
reaches, and the security model.
Action API — the surface an action uses to drive another
application: finding windows, searching element trees, waiting, filling fields.
Migrating from Keyhac for macOS — mostly drop-in.
Migrating from Keyhac for Windows — API renamed;
translation table.
Legacy products (no longer developed, kept for reference):
Keyhac for Windows 1.x,
Keyhac for macOS 1.x.
Developer documentation — architecture, platform layer, packaging,
testing. Project guide for coding agents: CLAUDE.md.

Running from source

python3 -m venv .venv
.venv/bin/pip install -e ".[dev]"
.venv/bin/python -m pytest          # engine + unit tests, no permissions needed
.venv/bin/python -m keyhac          # run (macOS: needs Accessibility permission)

python -m keyhac -d enables debug logging, --no-ui runs headless (hook + engine
only), --config PATH uses an alternate config file (its data files live beside it).

Contact & Support

GitHub Issues: Report bugs or request features
GitHub Discussions: Questions, ideas, and configs or actions to share
Security problems: report privately — see SECURITY.md
Contributing: CONTRIBUTING.md
PyPI: pypi.org/project/keyhac — released versions
Author's X (Twitter): @crftwr

License

MIT — see LICENSE.