Cast your whole screen or a single window to a Chromecast device, or send your system audio to a Chromecast speaker, smart display, or cast group, right from the GNOME Shell top panel.

The project has two parts, shipped together in this repository:

The two talk over the D-Bus session bus (org.gnome.ShellCast1). The daemon is D-Bus activatable, so it starts on demand and exits when idle.

Preferences and the quick settings menu while casting

Top-bar tray menu while casting

Chromecast's Default Media Receiver plays media it pulls over HTTP. When you start a cast:

1. The daemon opens an XDG ScreenCast portal session - GNOME shows its native picker for a monitor or a window.
2. A GStreamer pipeline captures the PipeWire stream, encodes H.264 video and AAC system audio, and writes a live HLS stream into $XDG_RUNTIME_DIR/gnome-shell-cast/.
3. A tiny built-in HTTP server serves that stream on your LAN.
4. The daemon tells the Chromecast (CASTv2 protocol) to play the stream URL.

Latency note: this HTTP/HLS approach - the same one tools like mkchromecast use - has an inherent delay of a few seconds. It is great for presentations, photos, and videos; it is not suitable for gaming.

Audio-only receivers (Chromecast Audio, Google/Nest speakers and smart displays, cast groups) advertise no video, and their Default Media Receiver rejects the live HLS stream. For them the daemon skips screen capture entirely and streams your system audio as a continuous MP3 (falling back to AAC) over HTTP, the way an internet-radio station does. Pick such a device from the menu and it offers a single Cast audio action.

Missing a plugin? See docs/DEPENDENCIES.md for per-distro package lists (Debian/Ubuntu, Fedora, Arch, openSUSE) and a symptom-to-fix table.

• GNOME Shell 48–50 (Wayland or X11; capture uses the ScreenCast portal)
• PipeWire + xdg-desktop-portal-gnome (default on any modern GNOME distro)
• GStreamer 1.x with plugins: base, good, bad, ugly (for x264enc) and libav (for AAC encoding). Audio-only casts use lamemp3enc (from good) with AAC as a fallback
• pactl (pulseaudio-utils) for locating the system-audio monitor device
• Rust toolchain (only to build the daemon)

Debian/Ubuntu build + runtime packages:

sudo apt install libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev \
    gstreamer1.0-plugins-good gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly \
    gstreamer1.0-libav gstreamer1.0-pipewire pulseaudio-utils cargo

Fedora:

sudo dnf install gstreamer1-devel gstreamer1-plugins-base-devel \
    gstreamer1-plugins-good gstreamer1-plugins-bad-free gstreamer1-plugins-ugly \
    gstreamer1-libav pipewire-gstreamer pulseaudio-utils cargo

If you got the extension from extensions.gnome.org, install the daemon separately (it can't be shipped there). The extension makes this easy: until the daemon is present, its menu shows a “Set up the cast daemon” item that opens a dialog with a ready-to-copy command. It downloads a checksum-verified binary for your CPU from the project's GitHub Releases into ~/.local/bin - nothing runs as root:

curl -fsSL https://raw.githubusercontent.com/omid/gnome-shell-cast/refs/heads/main/scripts/install.sh | sh

(The dialog fills in the version matching your installed extension.) You can inspect scripts/install.sh before running it.

Updating: when the extension updates to a version that needs a newer daemon, its menu shows “Update the cast daemon (v… → v…)” - run the same command from that dialog and it installs the matching release.

Uninstall:

rm -f ~/.local/bin/gnome-shell-cast-daemon \
      ~/.local/share/dbus-1/services/org.gnome.ShellCast.service

To build and install both halves from this repository:

make install-local

This builds the daemon (cargo build --release) and installs:

• the extension to ~/.local/share/gnome-shell/extensions/gnome-shell-cast@oxygenws.com
• the daemon binary to ~/.local/bin/gnome-shell-cast-daemon
• the D-Bus activation file to ~/.local/share/dbus-1/services/

Then log out and back in (Wayland), and enable the extension:

gnome-extensions enable gnome-shell-cast@oxygenws.com

(make install-daemon installs only the daemon half - useful on a machine that already has the extension from extensions.gnome.org but no supported prebuilt binary.)

1. Click the cast icon in the top panel.
2. Pick a Chromecast from the discovered device list.
3. Choose Cast screen or Cast window - GNOME's picker dialog opens for the source. Audio-only devices (speakers, cast groups) show a single Cast audio action instead.
4. To end, click the icon and choose Stop casting.

Preferences (resolution cap, framerate, bitrate) are under the ⚙ menu entry or gnome-extensions prefs gnome-shell-cast@oxygenws.com.

# Extension logs
journalctl -f -o cat /usr/bin/gnome-shell

# Daemon logs (every line is tagged "gnome-shell-cast")
journalctl --user -f -g gnome-shell-cast
# or run it by hand with verbose logging:
RUST_LOG=debug ~/.local/bin/gnome-shell-cast-daemon

• No devices found: the Chromecast must be on the same network/VLAN, and mDNS (UDP 5353) must not be blocked.
• No audio: system audio is captured from the default sink's monitor via pactl get-default-sink. Check pactl is installed and audio isn't going to a different sink.
• Playback fails on the TV: confirm gst-inspect-1.0 x264enc hlssink2 finds both elements.

1. make install-local, re-login, enable the extension.
2. Panel shows the cast icon; menu lists your Chromecast within ~5 s.
3. Cast Screen → portal picker → picture appears on the TV in a few seconds, with system audio.
4. Cast Window → portal shows only windows; only that window is streamed.
5. Stop Casting → TV returns to the ambient screen; daemon exits after ~10 min idle.

• A few seconds of latency on the HTTP/HLS fallback (low-latency Cast Streaming is used when the receiver supports it).
• Resolutions above 1080p realistically need a hardware encoder (VA-API or NVENC); software encoding above 1080p will not keep up in realtime. Raise the bitrate to match the resolution — the default 4000 kbit/s suits 720p.
• With resolution set to Native, Cast Streaming advertises 1080p to the receiver regardless of the captured size.
• Sender and Chromecast must be on the same LAN.
• DRM-protected content will be black in the capture.
• Audio is the full system mix (no per-app capture).

MIT.

The Cast Streaming protocol code in daemon/src/streaming/openscreen/ is a port of Chromium's openscreen cast/streaming and is used under its BSD-3-Clause licence — see NOTICE and daemon/src/streaming/openscreen/NOTICE for the required attribution. "Google Cast" and "Chromecast" are trademarks of Google LLC; this project is not affiliated with Google.