KeyStitch

⌘  ───────  KeyStitch  ───────  Ctrl

Seamless input across machines.

A Barrier-based cross-platform input project that preserves natural keyboard behavior across Windows, macOS, and Linux.

Barrier lets one keyboard and mouse control multiple computers. KeyStitch keeps the keyboard's meaning intact while the pointer moves between them.

The problem

The pointer can cross an OS boundary naturally. Keyboard semantics often cannot:

• Ctrl and Command are not interchangeable
• Alt and Option have different meanings
• left and right modifiers can arrive as different events
• Korean Windows layouts may report Right Alt as Hangul
• input-source switching depends on the receiving platform

Tools such as Karabiner-Elements and AutoHotkey are useful on local machines, but remote Barrier input may not reach them as ordinary local keyboard input.

The insight

Instead of fixing the key after it reaches the destination OS, translate its meaning before Barrier sends it.

The solution

KeyStitch adds a target-screen-aware input semantics layer to Barrier. The existing mouse-edge switching experience stays intact, while configured keyboard rules are translated for the destination machine.

Physical keyboard / mouse
          │
          ▼
    Barrier server
          │
          ▼
   ┌────────────────┐
   │   KeyStitch    │
   │  Remap         │
   │  Tap / Hold    │
   │  Modifiers     │
   │  Input source  │
   └────────────────┘
          │
    Barrier protocol
          │
     ┌────┴────┐
     ▼         ▼
  Windows    macOS

What KeyStitch adds

• Per-screen remapping — rules can target a specific remote machine
• Tap / hold modifiers — one key can have separate tap and hold behavior
• Cross-OS modifier translation — map Windows and macOS conventions
• Hotkey chord remapping — translate combinations such as Control+Space
• Korean Hangul key handling — distinguish Right Alt and Hangul
• Extended macOS function keys — support platform-specific key paths
• Keyboard + mouse sharing — the proven Barrier workflow remains intact

The remapping layer only affects configured keyboard rules on configured screens. Barrier's normal mouse and clipboard behavior remains available.

Quick example

Remaps are configured in a section: remaps block and can be scoped per target screen:

section: remaps
  mac:
    right_alt.alone = F19
    right_alt.hold = right_super
    hangul.alone = F19
    hangul.hold = right_super
    control+space = F19

  windows:
    left_super = left_control
    right_super.alone = hangul
end

See the key remap guide for the supported configuration syntax, examples, limitations, and verification commands.

Downloads

Download Linux and macOS builds from the releases page. Releases include .sha256 files for verifying downloaded archives.

Documentation

• Key remaps
• Windows/macOS test handoff
• macOS virtual HID keyboard
• macOS client input stutter
• Release checklist

The documentation records both user-facing behavior and the investigation behind platform-specific input decisions.

Build and test

The project uses CMake. The repository contains platform build scripts and GitHub Actions workflows for CI and release packaging. For the manual release and verification flow, see the release checklist.

Relationship to Barrier

KeyStitch is an unofficial modified build based on Barrier. It is not affiliated with or endorsed by the upstream Barrier maintainers.

The original Barrier project and its package ecosystem are available at https://github.com/debauchee/barrier.

KeyStitch aims to contribute useful fixes and documentation upstream where appropriate, while providing a focused build for cross-platform keyboard semantics.

Support and contributions

For KeyStitch remapping, packaging, or release issues, open an issue in this repository: https://github.com/johneybi/keystitch/issues.

For bugs that also reproduce in upstream Barrier without a section: remaps configuration, report them to the upstream Barrier project.

Contributions are welcome, especially around remap rules, platform key-code coverage, tests, and release packaging.

License

KeyStitch follows the licensing terms of the Barrier source tree. See LICENSE for details.