Syltr

An all-in-one messaging service aggregator, native to GNOME. It gathers WhatsApp Web, Telegram, Slack, Discord, Messenger and any other web service into a single window — each with its own isolated session (separate cookies and storage).

Stack: GTK4 · libadwaita · WebKitGTK 6 · Rust

Features

• Theme-aware welcome screen until a service is selected
• Icon rail with real, persistent favicons (SVG fallback included) and an active-item highlight
• Add services from a catalog or by custom URL
• Reorder services by dragging · context menu (right click)
• Unread badges on the icon (detected from the page title)
• Native desktop notifications · mute per service · global do not disturb
• Spell checking with the system dictionaries (enchant/hunspell)
• Links clicked in messages (target=_blank) open in the default browser; SSO popups and in-service navigation stay in-app, with back/forward
• Isolated session per service (independent login for each)
• Downloads saved straight to ~/Downloads with a completion notification
• Camera, microphone and WebRTC call support
• Service list persisted in ~/.config/dev.syltr.Syltr/services.json

Shortcuts

Shortcut	Action
Ctrl+1 … Ctrl+9	Go to service N
Ctrl+PgDown / Alt+↓	Next service
Ctrl+PgUp / Alt+↑	Previous service
Ctrl+N	Add service
Ctrl+R / F5	Reload
Ctrl+Q	Quit

Development

Install the dependencies (Arch Linux):

./scripts/install-deps.sh          # toolchain, GTK4/libadwaita, WebKitGTK, spell check
./scripts/install-deps.sh --no-ide # skip GNOME Builder

Build and run:

cargo run

Useful environment variables:

• SYLTR_DEBUG=1 — forward the pages' JS errors/warnings to stderr
• SYLTR_LOCALE_DIR — override the translations directory
• SYLTR_SW_RENDER=1 — disable hardware acceleration as a troubleshooting fallback (heavy web apps may use substantially more memory)
• SYLTR_TEAMS_CALLS=1 — opt into experimental Teams calls; disabled by default because WebKitGTK's WebRTC/PipeWire path can hang Teams

Media codecs (WhatsApp video)

WebKitGTK plays media through GStreamer, so H.264/AAC (WhatsApp videos) work with the system codecs — on Arch, install gst-plugins-good and gst-libav. No engine rebuild involved.

Camera, microphone and calls

Media capture and WebRTC are enabled for all services. On Arch they require gst-plugin-pipewire, gst-plugins-bad and libnice. WebKitGTK's PipeWire device monitor is known to crash on some systems, so this support remains experimental despite being enabled by default.

Tests

cargo test

Unit tests are colocated with the code they test: a module gains a tests submodule declared as #[cfg(test)] mod tests;, with the tests living in a sibling tests.rs inside the module folder (e.g. src/engine/unread/tests.rs). This keeps them out of the release build and gives them access to the module's internal (pub(crate)/private) items.

Architecture

The app talks to the web engine only through the public engine::ServiceView API and never touches webkit6 directly. Each module is split into a folder by responsibility:

Path	Responsibility
src/main.rs	AdwApplication startup, i18n, CSS, embedded resources
src/window/	Window, rail, view stack, actions, dialogs, context menu
src/engine/	Web engine layer (WebKitGTK 6): sessions, favicons, unread, downloads, ServiceView
src/config/	Service list, settings and their XDG file locations
src/spellcheck.rs	Discovery of system spell-check dictionaries
src/catalog.rs	Catalog of known services ("recipes")
src/icon.rs	The service icon (tile + favicon + unread badge)

Web engine (WebKitGTK 6)

Each service is a webkit6::WebView with its own NetworkSession (cookies, storage and cache isolated under the service's session directory). The latest real favicon is cached alongside that session and remains available while the service is suspended or disabled. Only the selected service stays loaded by default. Background activity can be enabled per service from Edit service to keep notifications and unread badges updating; focused direct messengers use this mode by default, while heavier workspaces, mail, calendar, tasks, AI and custom services do not. Loaded background services keep JavaScript and WebSockets alive, while WebKit stops painting them and Syltr pauses infinite visual animations and automatic video. The page remains loaded, so real-time notifications stay available. The rest of the app depends only on ServiceView (new, widget, icon, reload, go_back, go_forward, go_home, set_notifications_enabled, set_active, set_spell_languages), so the engine internals stay contained in src/engine/.

Compatibility choices carried in the engine: hardware acceleration stays on because heavy SPAs can exhaust memory on the software path, Google Calendar uses a Safari user agent to avoid incompatible Chrome-specific code paths, media capture/WebRTC stays enabled except for Teams calls (experimental opt-in) because its PipeWire device-monitor path can hang, and a startup script shims Notification.permission and requestIdleCallback.

License

GPL-3.0-or-later