Show HN: Backlit Keyboard API for Python

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Summary

A beginner-friendly Python package and CLI tool to control keyboard backlight brightness on Linux with mock-safe testing.

It currently supports Linux as of now. You can use this package to tinker with many things. Let's say, if you want to make a custom notification system, like if your website is down, you can make a blink notification with it. MacOS support is underway. I haven't tested Windows yet, I don't use it anymore btw. In future, if this package reaches nice growth, I'll be happy to make a similar Rust crate for it.
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Cached at: 04/22/26, 01:59 AM

itsmeadarsh2008/backlit-kbd

Source: https://github.com/itsmeadarsh2008/backlit-kbd

backlit-kbd

CI Publish PyPI version Python License Downloads Buy Me A Coffee Sponsor

Beginner-friendly Python package to control keyboard backlight brightness.

It supports:

  • Real Linux keyboard backlight devices (auto-discovered from sysfs)
  • A mock backend for safe testing without touching laptop hardware

What This Means

  • If you use --mock, commands run in memory only (safe for learning).
  • If you do not use --mock, the package tries real hardware automatically.
  • You usually do not need --device-path.

Installation

Step 1: Install from PyPI

pip install backlit-kbd

Step 2 (optional): Install local editable version for development

pip install -e .

Step 3 (optional): Install dev dependencies

pip install -e .[dev]

Quick Start (Python)

Step 1: Import

from backlit_kbd import NotificationBlinker, create_controller

Step 2: Create a safe controller (mock fallback)

controller = create_controller(fallback_to_mock=True)

Step 3: Turn on brightness to 60%

controller.turn_on(60.0)

Step 4: Blink for a notification

controller.blink(count=3, on_ms=120, off_ms=120, level_percent=100.0)

Step 5: Use async notification manager

blinker = NotificationBlinker(controller)
blinker.start("chat-message", count=5, on_ms=80, off_ms=120)

CLI Guide (Beginner Friendly)

1) Check Current State

With mock backend:

backlit-kbd --mock info

With real hardware backend:

backlit-kbd info

2) Set Brightness by Raw Level

With mock backend:

backlit-kbd --mock set 2

With real hardware backend:

backlit-kbd set 2

3) Set Brightness by Percentage

With mock backend:

backlit-kbd --mock percent 75

With real hardware backend:

backlit-kbd percent 75

4) Increase and Decrease

Increase by default step (1):

backlit-kbd --mock inc

Increase by custom step:

backlit-kbd --mock inc 2

Decrease by custom step:

backlit-kbd --mock dec 2

Real hardware equivalents:

backlit-kbd inc
backlit-kbd inc 2
backlit-kbd dec 2

5) Turn On and Off

With mock backend:

backlit-kbd --mock on --percent 40
backlit-kbd --mock off

With real hardware backend:

backlit-kbd on --percent 40
backlit-kbd off

6) Blink Pattern (Synchronous)

With mock backend:

backlit-kbd --mock blink --count 4 --on-ms 100 --off-ms 100 --level-percent 100

With real hardware backend:

backlit-kbd blink --count 4 --on-ms 100 --off-ms 100 --level-percent 100

7) Notification Blink (Async-style Command)

With mock backend:

backlit-kbd --mock notify --name chat --count 5 --on-ms 80 --off-ms 120 --level-percent 100

With real hardware backend:

backlit-kbd notify --name chat --count 5 --on-ms 80 --off-ms 120 --level-percent 100

Full CLI Commands

Global options:

  • --mock Use in-memory backend (safe, no hardware writes)
  • --device-path PATH Optional advanced override for a specific sysfs device

Commands:

  • info
  • set <value>
  • percent <value>
  • inc [step]
  • dec [step]
  • on [--percent N]
  • off
  • blink [--count N --on-ms N --off-ms N --level-percent N]
  • notify [--name NAME --count N --on-ms N --off-ms N --level-percent N]

Examples Folder

Scripts:

  • examples/blink_notification.py
  • examples/brightness_wave.py
  • examples/disco_light.py

Run them:

python examples/blink_notification.py
python examples/brightness_wave.py
python examples/disco_light.py

Testing

Run tests:

python -m pytest

If you are using the project virtual environment:

.venv/bin/pytest

Troubleshooting

  1. Permission denied on Linux real hardware mode:
  • You may need proper privileges/udev rules to write to sysfs.
  1. No device found in real hardware mode:
  • Use --mock for learning/testing.
  • Or use create_controller(fallback_to_mock=True) in Python.
  1. Want safe practice mode always:
  • Use --mock in CLI, or force_mock=True / fallback_to_mock=True in code.

Release and Publish

This repo has GitHub Actions workflows:

  • CI runs tests on push and pull request
  • Publish builds and publishes to PyPI
  • Uses astral-sh/setup-uv
  • Uses PyPI Trusted Publishing (OIDC)

To publish a new version:

  1. Update version in pyproject.toml
  2. Create and push a tag like v0.1.1
  3. Or publish a GitHub release

Support

  • Buy Me a Coffee: https://buymeacoffee.com/itsmeadarsh
  • GitHub Sponsors (individual/company): https://github.com/sponsors/itsmeadarsh2008

Contributing

  • Start with examples/
  • Check tests in tests/
  • Open issues and PRs

License

MIT License. Created by Adarsh Gourab Mahalik.

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