Ditto is a system-wide ASCII keyboard visualizer that mirrors your live keyboard inputs in real time, even when the terminal isn't in focus. It automatically syncs with your native terminal color scheme for seamless, interactive eye candy. If you love it, drop a ⭐ on the repo!

Showcase

Table of Contents

• Motivation
• Installation
• Permissions
• Config
• Usage

• Roadmap
• Contributing
• Stargazers
• Resources
• Note on AI
• License

Motivation

If you've seen rices over at places like r/unixp\*rn, every now and then you'll see some developer layouts where you'd have a code editor, then some eye candy to fill up dead space. I thought it would be nice to have some eye candy that was interactive.

And so, I thought a keyboard visualizer that updates no matter which window has focus would be pretty neat. You code away on your editor, and the ASCII keyboard on the corner lights up!

Practically, it could have a niche use as well, like sharing your screen with other people so you can flex your Vim skills they can see the keys you press as you navigate through your workflow.

Installation

Linux

I recommend installing the program through Go:

go install github.com/arvingarciabtw/ditto/cmd/ditto@latest

Or you can install the program via the AUR:

yay -S ditto
or
paru -S ditto

Or via the flake for nix users:

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
ditto = {       url = "github:arvingarciabtw/ditto";       inputs.nixpkgs.follows = "nixpkgs";     };   };
# ... }

It's available under ditto.packages.<system>.default.

Before executing the program with ditto, refer to the permissions section below.

Windows

Download dittowindowsamd64.exe from the Releases page, put it somewhere convenient (e.g. C:\Users\<you>\bin or C:\Tools), and add that folder to your PATH.

macOS

Download dittodarwinarm64 (Apple Silicon) or dittodarwinamd64 (Intel) from the Releases page, rename it to dittokb, place it in a directory on your PATH (e.g. /usr/local/bin), and make it executable with chmod +x /path/to/dittokb.

[!NOTE]

macOS support is untested. The keymapper is implemented and it compiles via CI, but it hasn't been verified on a physical Mac. If you try it, please report any issues!

The binary is named dittokb rather than ditto on macOS, since ditto is already a built-in system utility (/usr/bin/ditto, used for copying directories/app bundles). All commands below that reference ditto should be run as dittokb instead.

Permissions

[!IMPORTANT]

For Linux users:

To add support for Wayland compositors, keyboard events are captured via evdev. Ditto reads raw events from /dev/input/event\*, which isn't readable by normal users by default. You can grant the binary read access with:

sudo setcap capdacread_search=ep "$(which ditto)"

The program will inform you about this when executing without permissions.

This adds a single Linux capability to the binary, so it only bypasses the DAC read check on /dev/input/event*, nothing else. The binary still runs as your user, not as root. You'd need to re-run it if you rebuilt the binary. You can revoke anytime with:

sudo setcap -r "$(which ditto)"

To my knowledge, this is the safer way of granting permissions. You could technically add the user to the input group and it would work, but that'd be more unsafe since that would grant full control over all devices under /dev/input.

[!NOTE]

Since Nix store paths change on every rebuild, you'll need to re-run setcap after updating the flake input.

Config

Ditto stores its config file and custom layouts in a per-OS config directory:

• Linux: ~/.config/ditto/ (or $XDGCONFIGHOME/ditto/ if set)
• macOS: ~/Library/Application Support/ditto/
• Windows: %AppData%\ditto\

Usage

[!NOTE]

macOS users: substitute dittokb for ditto in all commands below.

There are four main commands you need to be aware of: l, s, d, and c. Pressing l opens up the layout list, s opens up the size list, and d opens up the standard list. If your active standard is either JIS or KS, you can press c to toggle between the Latin alphabet and the standard's logograms.

[!NOTE]

For the JIS and KS standards to render the logograms properly, you need to have a compatible font installed in your system. I recommend Noto Sans CJK JP and Noto Sans CJK KR.

If you'd like to only see the keyboard, you can hide the informational text with h.

Lists

Size List

Press s to open the size list. This determines which physical key matrix the ASCII keyboard renders. Choose from compact 60% all the way up to full-size 100%.

Layout List

Press l to open the layout list. This determines how the keys are remapped. Choose from popular layouts like QWERTY, Dvorak, Colemak, and more.

Standard List

Press d to open the standard list. This determines the physical keyboard standard. Choose from ANSI, ISO, ABNT, JIS, or KS.

Custom Layouts

Custom layouts are loaded from a layouts/ folder inside ditto's config directory.

Each .json file becomes a named layout (the filename without extension). Format:

{
  "map": {
    "A": "A",
    "S": "O",
    "D": "E",
    "F": "U",
    "G": "I",
    "H": "D",
    "J": "H",
    "K": "T",
    "L": "N",
    "Q": "'",
    "W": ",",
    "E": ".",
    // ...
  },
  "shift": {
    "1": "!",
    "2": "@", // ...
  },
}

• map is required — maps physical key labels → remapped labels (same format as the built-in layouts in layouts.go)
• shift is optional — shifted state mappings; falls back to shift mappings for qwerty us layout if omitted

Lock

If you're happy with the current layout and want to keep that permanently every time you run the program, you can lock the keyboard with ditto --lock. Locking it means that your visual settings will not work. Bindings for opening up a list, toggling the TUI text with h, or toggling the logograms with c will intentionally not work.

Inversely, you can just do ditto --unlock to unlock the keyboard.

If you prefer, you can also just edit config.json in ditto's config directory directly to change the value of the locked key.

Roadmap

Some features I'm thinking of implementing in the future, not in order.

• [x] Physical layouts (standards)
• [x] Cross-platform support
• [ ] Keycast mode
• [ ] Smoother variant with box drawing characters
• [ ] Layers
• [ ] Custom layouts via TUI

Contributing

I'm certainly not much of an experienced programmer, so any contributions you make are greatly appreciated.

As I kept developing this program, I've learned that keyboards actually get pretty deep. For instance, check out this list of QWERTY keyboard language variants. If you'd like to add a specific layout variant to the layout list, I'd appreciate a pull request or opening up an issue about it.

When writing my commit messages, I follow the Conventional Commits spec, so I'd be glad if you followed this convention as well for your contributions for the sake of consistency.

If you're liking Ditto, I'd appreciate a star! Thanks again! ⭐

Stargazers

Huge thanks to everyone that found the project interesting! :)

Resources

Here is a list of useful resources that I always refer to when developing:

• effective go
• bubble tea docs
• lipgloss docs
• evdev docs
• input interfaces
• setcap
• standards reference

Note on AI

I'm not an experienced programmer and I've only recently picked up Go, so I'm well aware that the codebase is subpar. I still don't have an eye for what is considered idiomatic Go or not.

I've used AI to assist me with making this project, notably for pointing me towards reliable resources like documentation and for easily doing tedious, repetitive tasks (especially so for when I was adding the key matrices for each keyboard standard's size).

In the cases where I couldn't figure out an implementation despite researching on my own, I did lean into AI for suggestions, and sometimes an initial prototype of an implementation. Rest assured that I did my best in reviewing these suggestions, and making appropriate changes along the way.

Of course, I'm certain the code can still be improved a lot more, so I'd be happy to hear any feedback or suggestions. If you'd like to contribute, you can refer to the Contributing section above.

License

Distributed under the MIT License. See LICENSE for more information.