BlueLock

Lock and unlock your KDE desktop session based on Bluetooth device proximity.

BlueLock monitors a paired Bluetooth device's signal strength. When the device moves out of range the session is locked automatically; when it returns the session is unlocked.

Features

• System tray icon with five states reflecting proximity and lock status
• Configurable RSSI thresholds with hysteresis (separate lock/unlock levels)
• Configurable time durations before acting (avoids triggering on momentary drops)
• D-Bus org.freedesktop.ScreenSaver for lock/unlock — no extra tools required
• Optional custom lock/unlock shell commands
• RSSI smoothing with a configurable ring buffer
• Real-time signal strength display in the configuration dialog

Requirements

• Python 3.11+
• PyQt6 (python3-pyqt6-base on Fedora)
• BlueZ (bluez)

Installation

From source

pip install .
bluelock

Development

make run

RPM (Fedora)

make rpm
sudo rpm -i ~/rpmbuild/RPMS/noarch/bluelock-*.rpm

Usage

1. Launch BlueLock — it appears in the system tray.
2. Right-click the tray icon and choose Preferences.
3. Click Scan to find nearby Bluetooth devices.
4. Select your device and click Use.
5. Adjust the lock/unlock RSSI thresholds and durations to taste.
6. Click OK — monitoring begins immediately.

Tray icon states

Icon	Meaning
Close (blue)	Device is nearby — session is unlocked
Far (yellow/amber)	Device is moving away — lock countdown active
Gone (red)	Device is absent — session is locked
Error (grey)	Initialising, or no signal yet
Paused	Monitoring is paused — no automatic lock/unlock

Thresholds

Setting	Description
Lock RSSI	Session locks when signal drops below this level
Lock duration	Signal must stay below the threshold for this many seconds before locking
Unlock RSSI	Session unlocks when signal rises above this level
Unlock duration	Signal must stay above the threshold for this many seconds before unlocking

The gap between the lock and unlock thresholds acts as a hysteresis band, preventing the session from oscillating when you are standing right at the boundary.

Configuration file

Saved at ~/.config/bluelock/config.toml.

Development

make test        # run tests
make coverage    # run tests with coverage report
make lint        # run ruff
make format      # auto-format with ruff
make build       # build wheel and sdist
make release V=X.Y.Z  # tag and publish a release

License

Unlicense — public domain.