Signpost

A link chooser for the COSMIC™ desktop. Make Signpost your default handler for web links, and every link you open from any app shows a small picker of your browsers, each browser profile, and the other apps that can open it. Pick one and the link opens there.

• Every profile of Chrome, Chromium, Brave, Edge, Vivaldi, Helium, Firefox, LibreWolf, Zen and Floorp as a tile of its own.
• Keyboard first: arrows and Enter, number keys for the first nine tiles, Ctrl+Enter to keep the picker open, Ctrl+C to copy the link, Esc to close it.
• A tile's menu (right-click, Menu key, or touch and hold) opens a private window or one of the app's own actions.
• Links that arrive while the picker is open wait their turn, and a link sent twice at once opens once.
• Signpost stays running, so the picker appears at once. It follows your COSMIC theme, frosted windows included.
• It never changes your default browser until you press Use Signpost, and Restore defaults puts back the one you had.

Install

Download the latest release from the Releases page and check it against SHA256SUMS:

sha256sum --check --ignore-missing SHA256SUMS

Pop!_OS, Ubuntu and other Debian-based systems:

sudo apt install ./signpost_0.1.0_amd64.deb

Flatpak, on any distribution. Its runtime comes from Flathub:

flatpak remote-add --if-not-exists --user flathub https://dl.flathub.org/repo/flathub.flatpakrepo
flatpak install --user ./signpost-0.1.0.flatpak

Install one or the other, not both. Each keeps its own record of the browser it replaced, so press Restore defaults in the one you set up before you switch to the other or uninstall it.

First use

1. Open Signpost from the app library. Its settings window opens.
2. Press Use Signpost. Signpost becomes the default handler for http and https links in your user mimeapps.list, and records the previous ones so they can be restored.
3. Open a link in any app. The picker appears.

To go back, open the same window and press Restore defaults. It puts back the http and https defaults Signpost recorded. Restore before you uninstall, because uninstalling removes the window that has the button.

The Flatpak

Signpost has to see your whole desktop to do its job, so its Flatpak is not a tight sandbox. It can:

• read all your files, so the picker shows the apps, default apps and browser profiles you have, including the profiles of these browsers installed as Flatpaks: Chrome, Chromium, Brave, Brave Origin, Vivaldi, Edge, Firefox, LibreWolf, Zen and Floorp;
• write only to ~/.config (besides its own data), where Use Signpost and Restore defaults edit your mimeapps.list;
• use the session bus, to start when a link arrives and to open apps that start that way;
• start apps outside the sandbox, each in a systemd scope of its own when your system makes them, so an app you open keeps running after Signpost stops.

Some limits:

• A mimeapps.list that links into a folder outside ~/.config cannot be changed until you let the Flatpak write there (see Troubleshooting).
• Signpost notices an app that fails within 3 seconds of starting. In the Flatpak, those 3 seconds include starting it outside the sandbox.
• An app whose icon comes only from a Flatpak installed for all users, or only from ~/.local/share/icons, shows the generic app icon.

Build from source

You need Rust 1.93 or newer, just, and the Wayland and XKB development packages (libwayland-dev, libxkbcommon-dev and pkg-config on Pop!_OS and Ubuntu).

just build              # release build, as yourself
sudo just install       # copies the files under /usr; never runs cargo
sudo just uninstall     # removes everything install put in place

just install only copies files, so root never needs your Rust toolchain. It refuses to install a binary that was not built from the checkout's current commit, or a checkout with uncommitted changes. To see what it installs without touching your system:

just build
stage=$(mktemp -d)
just DESTDIR="$stage" prefix=/usr install
find "$stage" -type f
rm -rf "$stage"

just deb packages the build as target/deb/signpost_<version>_<arch>.deb, and needs dpkg-dev. Like just install, it refuses a binary that was not built from the checkout's current commit. just flatpak builds target/flatpak/signpost-<version>.flatpak with flatpak-builder, and needs the Freedesktop 26.08 SDK and its Rust extension:

flatpak install --user flathub org.freedesktop.Sdk//26.08 org.freedesktop.Sdk.Extension.rust-stable//26.08

The Flatpak builds offline from cargo-sources.json. After changing Cargo.lock, regenerate it with flatpak-cargo-generator.py: python3 flatpak-cargo-generator.py Cargo.lock -o cargo-sources.json. just validate runs formatting, pedantic Clippy, the tests, the desktop and AppStream checks, the staged install and the package, and also needs desktop-file-utils, appstream and dbus.

Troubleshooting

The picker never appears and the log says "WAYLAND_DISPLAY is not set". D-Bus started Signpost without your session's display. Run dbus-update-activation-environment --systemd WAYLAND_DISPLAY XDG_CURRENT_DESKTOP (COSMIC normally does this at login), then open a link again.

Signpost still behaves like the old version after an update. It stays running between links. Stop it with kill -TERM $(busctl --user status com.lkbddh.signpost | sed -n 's/^PID=//p'); the next link starts the new one.

The Flatpak cannot set itself as default, and says it cannot write your mimeapps.list. Your ~/.config/mimeapps.list is a link to a file in a folder the Flatpak can read but not write, such as a dotfiles checkout. The failed attempt changed nothing. Let the Flatpak write to that folder, then press Use Signpost again:

flatpak override --user --filesystem=/path/to/that/folder com.lkbddh.signpost

Contributing

See CONTRIBUTING.md. Report security problems as described in SECURITY.md.

License

GPL-3.0-or-later. See LICENSE. Third-party notices are in THIRD_PARTY_NOTICES.md and their license texts in THIRD_PARTY_LICENSES.md.

COSMIC is a trademark of System76, Inc. Signpost is an independent project, not affiliated with or endorsed by System76.