# Keyhac 2
English \| [日本語](README.ja.md)
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](#documentation) below.
Keyhac 2's UI is built on [PuiKit](https://github.com/crftwr/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](#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:
```python
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](doc/ai-integration.md) 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--macos.dmg` from
[Releases](https://github.com/crftwr/keyhac/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](https://apps.microsoft.com/detail/9P8H1PG6PRHH)
(or `winget install --id 9P8H1PG6PRHH --source msstore`) — automatic updates, no
SmartScreen warning. Alternatively, download `Keyhac--win64.zip` from
[Releases](https://github.com/crftwr/keyhac/releases), unzip anywhere and run
`Keyhac.exe`.
Details, data locations and privacy notes: [doc/installation.md](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:
```python
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](doc/configuration.md), the per-symbol
reference [doc/config-api.md](doc/config-api.md); the shipped template
([keyhac/_config.py](keyhac/_config.py)) is a working tour of every feature.
## Documentation
- [Installation](doc/installation.md) — install, permissions, data files, privacy.
- [Configuration](doc/configuration.md) — the complete config.py guide.
- [API reference](doc/config-api.md) — every class and function a config.py
can reach, with its exact arguments.
- [AI integration](doc/ai-integration.md) — connect an MCP client, what the endpoint
reaches, and the security model.
- [Action API](doc/action-api.md) — the surface an action uses to drive another
application: finding windows, searching element trees, waiting, filling fields.
- [Migrating from Keyhac for macOS](doc/migration-from-keyhac-mac.md) — mostly drop-in.
- [Migrating from Keyhac for Windows](doc/migration-from-keyhac-win.md) — API renamed;
translation table.
- Legacy products (no longer developed, kept for reference):
[Keyhac for Windows 1.x](https://github.com/crftwr/keyhac-win),
[Keyhac for macOS 1.x](https://github.com/crftwr/keyhac-mac).
- [Developer documentation](doc/dev/) — architecture, platform layer, packaging,
testing. Project guide for coding agents: [CLAUDE.md](CLAUDE.md).
## Running from source
```sh
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](https://github.com/crftwr/keyhac/issues/new/choose)
- **GitHub Discussions**: [Questions, ideas, and configs or actions to share](https://github.com/crftwr/keyhac/discussions)
- **Security problems**: report privately — see [SECURITY.md](SECURITY.md)
- **Contributing**: [CONTRIBUTING.md](CONTRIBUTING.md)
- **PyPI**: [pypi.org/project/keyhac](https://pypi.org/project/keyhac/) — released versions
- **Author's X (Twitter)**: [@crftwr](https://x.com/crftwr)
## License
MIT — see [LICENSE](LICENSE).