Bread

A reactive automation fabric for Linux desktops.

Bread is a modular desktop automation runtime built around a single idea: your desktop should behave like a programmable system, not a collection of disconnected config files.

Instead of scattering behavior across shell scripts, compositor configs, udev rules, and ad-hoc daemons, Bread centralizes runtime awareness into a coherent layer that can observe, interpret, and react to system state dynamically.

Status: Early development. The daemon (breadd) is stable. The Lua automation API is active and feature-complete for daily use.

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How it works

Bread runs a long-lived daemon (breadd) that:

1. Ingests raw signals from your compositor, hardware, and OS
2. Normalizes them into stable, semantic events (bread.device.dock.connected, bread.monitor.connected, etc.)
3. Maintains a live model of your desktop state
4. Delivers those events to Lua modules that implement your automation

Your automation lives in Lua. You subscribe to events, read state, and call APIs:

local M = bread.module({ name = "dock", version = "1.0.0" })

bread.on("bread.device.dock.connected", function(event)
    bread.profile.activate("desk")
    bread.exec("waybar --config ~/.config/waybar/desk.jsonc")
    bread.notify("Dock connected", { urgency = "low" })
end)

bread.on("bread.device.dock.disconnected", function(event)
    bread.profile.activate("default")
end)

return M

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Architecture

breadd/          Rust daemon — event pipeline, state engine, IPC, adapter supervision
bread-cli/       CLI frontend — talks to breadd over a Unix socket
bread-shared/    Shared types — RawEvent, BreadEvent, AdapterSource
packaging/       Arch PKGBUILD and systemd user service

The daemon is structured in four layers:

• Adapters — interface with Hyprland IPC, udev, power state, network interfaces, and Bluetooth (BlueZ)
• Normalizer — transforms raw adapter signals into semantic Bread events
• State engine — maintains runtime state and dispatches events to subscribers
• Lua runtime — loads your modules, registers handlers, executes automation

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Requirements

• Linux (Arch recommended)
• Wayland compositor (Hyprland for full functionality)
• Rust toolchain (stable, 2021 edition)
• udev (standard on systemd systems)

Optional but preferred:

• UPower (for battery events via D-Bus rather than sysfs polling)
• rtnetlink (for network events; falls back to sysfs polling without it)
• BlueZ (for Bluetooth device events and control)

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Installation

From source

git clone https://github.com/Breadway/bread.git
cd bread

Run the install script — it builds, symlinks breadd and bread into ~/.local/bin (override with BIN_DIR=…), installs the systemd user service, and starts the daemon:

bash scripts/install.sh

Or step by step (system-wide install):

cargo build --release
sudo install -Dm755 target/release/breadd /usr/bin/breadd
sudo install -Dm755 target/release/bread /usr/bin/bread

Arch Linux (PKGBUILD)

cd packaging/arch
makepkg -si

systemd user service

mkdir -p ~/.config/systemd/user
cp packaging/systemd/breadd.service ~/.config/systemd/user/
systemctl --user daemon-reload
systemctl --user enable --now breadd

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Configuration

Bread reads from ~/.config/bread/breadd.toml. All values are optional — the daemon runs with defaults if the file doesn't exist.

[daemon]
log_level = "info"   # trace | debug | info | warn | error

[lua]
entry_point = "~/.config/bread/init.lua"
module_path = "~/.config/bread/modules"

[adapters.hyprland]
enabled = true

[adapters.udev]
enabled = true
subsystems = ["usb", "input", "drm", "power_supply"]

[adapters.power]
enabled = true
poll_interval_secs = 30

[adapters.network]
enabled = true

[adapters.bluetooth]
enabled = true

[events]
dedup_window_ms = 100

[notifications]
default_timeout_ms = 5000
default_urgency = "normal"
notify_send_path = "notify-send"

[modules]
builtin = true    # load built-in modules (monitors, devices, workspaces, binds)
disable = []      # list of built-in module names to disable

Your automation lives in ~/.config/bread/init.lua. Modules placed in ~/.config/bread/modules/ are auto-loaded after init.lua:

-- ~/.config/bread/init.lua

bread.on("bread.system.startup", function(event)
    bread.profile.activate("default")
end)

---

CLI reference

All commands communicate with the running daemon over a Unix socket at $XDG_RUNTIME_DIR/bread/breadd.sock.

# Daemon
bread ping                            # Check daemon connectivity
bread health                          # Daemon version, uptime, PID
bread doctor                          # Diagnose daemon and module health

# Lua runtime
bread reload                          # Hot-reload all Lua modules
bread reload --watch                  # Watch config dir and reload on changes

# State and events
bread state                           # Dump full runtime state as JSON
bread events                          # Stream live normalized events
bread events bread.device.*           # Stream filtered events
bread events --since 60               # Replay events from the last 60 seconds
bread emit <event>                    # Manually fire an event (for testing)

# Profiles
bread profile-list                    # List defined profiles
bread profile-activate <name>         # Activate a named profile

# Modules
bread modules list                    # List installed modules and daemon status
bread modules install /local/path     # Install from a local module directory
bread modules remove <name>           # Remove an installed module
bread modules info <name>             # Show full manifest and daemon status

---

Module system

Modules are Lua files (or directories) installed to ~/.config/bread/modules/. Each module must declare itself with bread.module() and have a bread.module.toml manifest.

Installing modules

Modules install from a local directory only. Modules run with full bread.exec() privileges and are not sandboxed, so to use a module published on a git host, clone it yourself and review the Lua before installing from the local checkout:

git clone https://github.com/someuser/bread-wifi ~/src/bread-wifi
# review ~/src/bread-wifi, then:
bread modules install ~/src/bread-wifi

Writing a module

A module directory looks like:

~/.config/bread/modules/
└── wifi/
    ├── bread.module.toml    ← required manifest
    └── init.lua             ← entry point

bread.module.toml:

name = "wifi"
version = "1.0.0"
description = "WiFi management for Bread"
author = "someuser"
source = "/home/you/src/bread-wifi"
installed_at = "2026-01-01T00:00:00Z"

init.lua:

local M = bread.module({ name = "wifi", version = "1.0.0" })

bread.on("bread.network.connected", function(event)
    bread.log("Network up: " .. (event.data.interface or "unknown"))
end)

return M

---

Event reference

Events follow the namespace convention bread.<subsystem>.<noun>.<verb>.

Event	Trigger
bread.system.startup	Daemon fully initialized
bread.device.connected	Any device attached
bread.device.disconnected	Any device removed
bread.device.<device>.connected	Named device attached (name from devices.lua)
bread.device.<device>.disconnected	Named device removed
bread.monitor.connected	Display connected
bread.monitor.disconnected	Display disconnected
bread.workspace.changed	Active workspace changed
bread.window.focus.changed	Focused window changed
bread.window.opened	Window opened
bread.window.closed	Window closed
bread.power.ac.connected	AC adapter plugged in
bread.power.ac.disconnected	AC adapter unplugged
bread.power.battery.low	Battery ≤ 20%
bread.power.battery.very_low	Battery ≤ 10%
bread.power.battery.critical	Battery ≤ 5%
bread.power.battery.full	Battery at 100%
bread.network.connected	Network interface came online
bread.network.disconnected	Network interface went offline
bread.bluetooth.device.paired	Bluetooth device paired / discovered
bread.bluetooth.device.unpaired	Bluetooth device removed from BlueZ
bread.profile.activated	Profile switched
bread.notify.sent	Desktop notification dispatched

---

Lua API

Modules

Every module file must declare itself. The declaration is used for dependency ordering and status tracking.

local M = bread.module({
    name    = "my-module",
    version = "1.0.0",
    after   = { "bread.devices" },   -- load after this module
})

-- ... module body ...

return M

Events

-- Subscribe to events; returns a subscription ID
local id = bread.on("bread.monitor.connected", function(event)
    -- event.event   → "bread.monitor.connected"
    -- event.data    → table of event-specific fields
    -- event.source  → adapter that produced it
    bread.log(event.event)
end)

-- Unsubscribe by ID
bread.off(id)

-- Subscribe once, auto-unsubscribe after first delivery
bread.once("bread.system.startup", function(event)
    bread.profile.activate("default")
end)

-- Subscribe with a filter predicate. The predicate goes in an opts table.
bread.filter("bread.device.connected", function(event)
    bread.exec("xset r rate 200 40")
end, {
    filter = function(event)
        return event.data.device == "keyboard"
    end,
})

-- Emit a custom event (for cross-module communication)
bread.emit("mymodule.something", { key = "value" })

Pattern matching supports * (single segment), ** (any depth), and ? (single character):

bread.on("bread.device.*", handler)   -- matches bread.device.dock.connected
bread.on("bread.device.**", handler)  -- matches any depth under bread.device

State

-- Read from runtime state by dot-separated path
local monitors = bread.state.get("monitors")
local online   = bread.state.get("network.online")

-- Typed shorthands
local monitors  = bread.state.monitors()
local workspace = bread.state.active_workspace()
local window    = bread.state.active_window()
local devices   = bread.state.devices()
local power     = bread.state.power()
local network   = bread.state.network()
local profile   = bread.state.profile()

-- Watch a state path for changes
bread.state.watch("power.ac_connected", function(new_val, old_val)
    if new_val then
        bread.notify("AC connected")
    end
end)

Profiles

bread.profile.activate("desk")
bread.profile.activate("default")

Execution and notifications

-- Fire-and-forget shell command
bread.exec("kitty")

-- Desktop notification (uses notify-send)
bread.notify("Title", { urgency = "normal", timeout = 3000, icon = "dialog-info" })
bread.notify("Simple message")   -- title defaults to "bread"

Timers

-- Run once after a delay (ms)
local id = bread.after(500, function()
    bread.exec("some-delayed-command")
end)

-- Run on a repeating interval (ms)
local id = bread.every(60000, function()
    bread.log("tick")
end)

-- Cancel either kind
bread.cancel(id)

-- Debounce a rapidly-firing handler
local fn = bread.debounce(200, function(event)
    reconfigure_monitors()
end)
bread.on("bread.monitor.*", fn)

Wait (inside coroutines)

-- Yield until a matching event arrives
local event = bread.wait("bread.device.dock.connected", { timeout = 5000 })
if event then
    -- dock arrived within 5 seconds
end

Machine and filesystem

-- Machine identity (system hostname)
local name = bread.machine.name()
local tags = bread.machine.tags()       -- array of strings
local ok   = bread.machine.has_tag("laptop")

-- Filesystem helpers (~ is expanded)
bread.fs.write("~/.config/some/file", "content")
local content = bread.fs.read("~/.config/some/file")   -- nil if not found
local exists  = bread.fs.exists("~/some/path")
local abs     = bread.fs.expand("~/some/path")

Logging

bread.log("Module loaded")     -- info level
bread.warn("Unexpected state") -- warn level
bread.error("Something failed") -- error level

Hyprland bindings

-- Dispatch a Hyprland command
bread.hyprland.dispatch("workspace", "2")
bread.hyprland.dispatch("exec", "kitty")

-- Set a keyword
bread.hyprland.keyword("monitor", "HDMI-A-1, 2560x1440, 0x0, 1")

-- Query compositor state
local win        = bread.hyprland.active_window()
local monitors   = bread.hyprland.monitors()
local workspaces = bread.hyprland.workspaces()
local clients    = bread.hyprland.clients()

-- Subscribe to raw Hyprland events (bypass normalization)
bread.hyprland.on_raw("activewindow", function(raw)
    -- raw is the unparsed string from Hyprland's event socket
end)

Bluetooth

The bread.bluetooth namespace provides BlueZ control. All operations degrade gracefully when Bluetooth hardware is unavailable.

-- Power the adapter on or off
bread.bluetooth.power(true)
bread.bluetooth.power(false)

-- Query current power state (returns true/false, or nil if unavailable)
local on = bread.bluetooth.powered()

-- Connect/disconnect a paired device by MAC address
-- Fire-and-forget; result arrives as bread.device.connected/disconnected
bread.bluetooth.connect("AA:BB:CC:DD:EE:FF")
bread.bluetooth.disconnect("AA:BB:CC:DD:EE:FF")

-- Start or stop device discovery
bread.bluetooth.scan(true)
bread.bluetooth.scan(false)

-- List all devices known to BlueZ
local devs = bread.bluetooth.devices()
-- Returns nil if BlueZ is unavailable, otherwise:
-- { { address, name, connected, paired }, ... }

Example — auto-connect headphones when Bluetooth powers on:

bread.state.watch("power.ac_connected", function(ac)
    if ac then
        bread.bluetooth.power(true)
        bread.bluetooth.connect("AA:BB:CC:DD:EE:FF")
    end
end)

Module-scoped storage

Survives hot reload; does not survive daemon restart.

M.store.set("last_profile", "docked")
local p = M.store.get("last_profile")  -- "docked"

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IPC protocol

The daemon exposes a Unix socket at $XDG_RUNTIME_DIR/bread/breadd.sock. The protocol is newline-delimited JSON — useful for scripting or building tooling outside the CLI.

Request:

{ "id": "1", "method": "state.get", "params": { "key": "monitors" } }

Response:

{ "id": "1", "result": [ { "name": "HDMI-A-1", "connected": true } ] }

Available methods:

Method	Description
ping	Connectivity check
health	Version, uptime, PID, adapter status
state.get	Read a value from RuntimeState by dotted key path
state.dump	Return the full RuntimeState as JSON
modules.list	List all loaded modules and their status
modules.reload	Hot-reload the Lua runtime
profile.list	List defined profiles
profile.activate	Switch active profile
events.subscribe	Upgrade connection to streaming mode
events.replay	Replay buffered events from the last N ms
emit	Inject a synthetic event into the pipeline

events.subscribe upgrades the connection to streaming mode — the daemon pushes events line by line until the client disconnects.

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Contributing

Bread is early-stage software. Contributions, issues, and feedback are welcome.

The daemon (breadd) is the most stable part of the codebase. Active development is happening across the Lua API and module system.

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License

MIT — see LICENSE.