fluxo is a high-performance system metrics daemon and client designed specifically for Waybar. It entirely replaces standard shell scripts with a compiled Rust binary that collects data via a background polling loop and serves it over a Unix socket.

With its 100% Native, Content-Based Event-Driven Architecture, it consumes effectively 0% CPU while idle and signals Waybar to redraw only when the rendered UI text or icons physically change.

Key Features

100% Native Architecture: Zero shell-outs or subprocesses. Uses bluer for Bluetooth, libpulse-binding for audio, zbus for MPRIS/DND, and notify for backlight.
Content-Based Event Signaling: fluxo evaluates your custom configuration formats internally. It only sends a SIGRTMIN+X signal to Waybar if the resulting string or CSS class has actually changed, eliminating pointless re-renders from raw polling fluctuations.
Zero-Latency Interactions: Direct library bindings mean that when you change your volume or connect a Bluetooth device via the CLI, the daemon updates instantly.
Circuit Breaker (Failsafe): Automatically detects failing modules and enters a "Cool down" state, preventing resource waste and log spam. Fallback caching keeps your bar looking clean even during brief failures.
Multi-threaded Polling: Decoupled Tokio subsystem threads ensure that a hang in one system (e.g., a slow GPU probe) never freezes your Waybar.

Modules

Command	Description	Tokens
`cpu`	CPU usage and temperature	`{usage}`, `{temp}`, `{model}`
`mem`	Memory usage	`{used}`, `{total}`
`net`	Network status & speeds	`{interface}`, `{ip}`, `{rx}`, `{tx}`
`sys`	System load and uptime	`{uptime}`, `{load1}`, `{load5}`, `{load15}`, `{procs}`
`disk`	Disk usage	`{mount}`, `{used}`, `{total}`
`pool`	Btrfs aggregate storage	`{used}`, `{total}`
`gpu`	GPU usage & thermals	`{usage}`, `{vram_used}`, `{vram_total}`, `{temp}`
`vol`	Audio output (sink)	`{name}`, `{volume}`, `{icon}`
`mic`	Audio input (source)	`{name}`, `{volume}`, `{icon}`
`bt`	Bluetooth status & plugins	`{alias}`, `{mac}`, `{left}`, `{right}`, `{anc}`
`power`	Battery and AC status	`{percentage}`, `{icon}`
`game`	Hyprland Gamemode status	active/inactive strings
`mpris`	Media Player status	`{artist}`, `{title}`, `{album}`, `{status_icon}`
`backlight`	Display Brightness	`{percentage}`, `{icon}`
`kbd`	Keyboard Layout	`{layout}`
`dnd`	Do Not Disturb (SwayNC)	active/inactive strings

Installation

From Source

cargo build --release
cp target/release/fluxo ~/.cargo/bin/

Debian/Ubuntu (.deb)

cargo install cargo-deb
cargo deb
sudo dpkg -i target/debian/fluxo-rs_*.deb

The .deb package installs the binary to /usr/bin/fluxo, the systemd user service to /usr/lib/systemd/user/fluxo.service, and documentation to /usr/share/doc/fluxo/.

Setup

Configure: Create ~/.config/fluxo/config.toml (see example.config.toml). Ensure you map your [signals].
Start the daemon via systemd (recommended) or manually:

systemd (recommended)

If installed from the .deb, the service file is already in place. For manual installs:

mkdir -p ~/.config/systemd/user
cp dist/fluxo.service ~/.config/systemd/user/

If your binary is not at ~/.cargo/bin/fluxo, edit the ExecStart= path in the service file.

Then enable and start:

systemctl --user daemon-reload
systemctl --user enable --now fluxo

Check status:

systemctl --user status fluxo
journalctl --user -u fluxo -f

Manual

fluxo daemon

Waybar Configuration

To achieve zero-latency updates and zero-polling CPU usage, set interval: 0 on your modules and rely entirely on Waybar Signals mapped in your config.toml:

"custom/volume": {
    "exec": "fluxo vol",
    "return-type": "json",
    "interval": 0,
    "signal": 8, // Must match the value in config.toml [signals]
    "on-click": "fluxo vol mute",
    "on-scroll-up": "fluxo vol up 1",
    "on-scroll-down": "fluxo vol down 1",
    "on-click-right": "fluxo vol cycle"
},
"custom/bluetooth-audio": {
    "format": "{}",
    "return-type": "json",
    "exec": "fluxo bt",
    "on-click": "fluxo bt menu",
    "on-click-right": "fluxo bt cycle_mode",
    "signal": 9,
    "interval": 0,
    "tooltip": true
}

Debugging

Use --loglevel to control log verbosity (trace, debug, info, warn, error):

fluxo daemon --loglevel debug

Or via the RUST_LOG environment variable:

RUST_LOG=debug fluxo daemon

For module help and available arguments:

fluxo help          # overview of all modules
fluxo help vol      # detailed help for a specific module