Arc

Arc Software is a Linux software manager that provides a unified interface for managing both Flatpak and native system packages. It wraps Flatpak (via libflatpak) and PackageKit both together with Appstream data behind a single D-Bus daemon, then exposes that daemon to a CLI tool and a graphical frontend.

Architecture

The project is organized as a Cargo workspace with four crates:

arc/
  crates/
    libarc/          Shared types and client library (D-Bus proxy)
    arc-daemon/      Background daemon (D-Bus service)
    arc-cli/         Command-line interface
    arc-frontend/    GUI application (Slint)

libarc

Foundation crate that every other crate depends on. It serves two roles:

1. Shared type definitions -- Package, Transaction, TransactionStatus, TransactionType, Provider, the ArcError error enum, and the ArcEvent enum used for signaling state changes. These live in the types, errors, and events modules and are re-exported from the crate root.

2. D-Bus client library -- Provides ArcDaemonProxy, a zbus-generated proxy for the dev.arc.ArcDaemon1 interface. The public API is a single connect() function that returns a ready-to-use proxy over the session bus. Both the CLI and the frontend depend on this to talk to the daemon.

arc-daemon

Long-running background process that registers itself on the session D-Bus as dev.arc.ArcDaemon1. It owns two package providers and a transaction manager:

• FlatpakProvider -- Uses libflatpak for install/remove/update operations and shells out to flatpak search for search queries. Scans both user and system installations.
• PackageKitProvider -- Communicates with the system PackageKit daemon over the system D-Bus (org.freedesktop.PackageKit). Handles native distro packages.
• MultiProvider -- Wraps both providers behind the PackageProvider trait. Search, list-installed, and list-updates queries fan out to both providers in parallel and merge the results. Mutating operations (install, remove, update) are routed to the appropriate provider based on the package ID format.
• TransactionManager -- Tracks in-flight and completed operations as Transaction objects keyed by UUID. The daemon emits D-Bus signals (TransactionStarted, TransactionProgress, TransactionFinished, UpdatesAvailable) so clients can follow progress asynchronously.

arc-cli

Command-line tool installed as arc. Built with clap, it supports:

• arc install <app_id> -- Install a package.
• arc remove <app_id> -- Remove a package.
• arc update -- List and apply all available updates.
• arc search <query> -- Search across all providers.
• arc list -- List installed applications.

Mutating commands poll the daemon for transaction progress and print a live status line until the operation completes or fails.

arc-frontend

Graphical application built with Slint. It connects to the daemon at startup (gracefully degrading with a warning if the daemon is unavailable), loads the installed application list, and presents a searchable package list with install/remove buttons and a progress indicator. Async D-Bus calls run on a Tokio runtime alongside the Slint event loop.

Communication Flow

 arc-cli / arc-frontend
        |
        |  (session D-Bus, dev.arc.ArcDaemon1)
        v
    arc-daemon
        |
        +---> FlatpakProvider  ---> libflatpak / flatpak CLI
        |
        +---> PackageKitProvider ---> org.freedesktop.PackageKit (system D-Bus)

All client-daemon communication happens over the session bus using JSON-serialized payloads. The daemon performs the actual privileged package operations and reports results back through return values and D-Bus signals.

Building

Install requirements:

sudo dnf install -y \
  rust cargo \
  flatpak-devel \
  fontconfig-devel \
  pkgconf-pkg-config \
  PackageKit PackageKit-glib-devel \
  dbus dbus-daemon

Then just run:

cargo build

The workspace produces three binaries:

Binary	Description
arc-daemon	Background daemon
arc	CLI tool
arc-frontend	Graphical frontend

Running

Start the daemon first, then use either client:

# Terminal 1
./target/release/arc-daemon

# Terminal 2 (CLI)
./target/release/arc search firefox
./target/release/arc install org.mozilla.firefox

# Or launch the GUI
./target/release/arc-frontend

The daemon logs can be controlled with the RUST_LOG environment variable (e.g. RUST_LOG=debug).