GNOME (Mutter)

Configure a host running GNOME. The host drives GNOME's Mutter compositor to create a per-client virtual display over D-Bus (RecordVirtual), zero-copy. This page assumes the host is already installed, see Ubuntu, Fedora, or Arch.

New here? Read Security & Safe Use first, a streaming host is remote control of the machine, so keep it on a trusted LAN or VPN and require pairing.

host.env

The host auto-detects the compositor from your live session on every connect, so the starter ~/.config/slipstream/host.env is one line:

# ~/.config/slipstream/host.env  (keys are case-sensitive)
SLIPSTREAM_VIDEO_SOURCE=virtual
# GPU zero-copy (dmabuf -> CUDA -> NVENC) is ON by default; auto-falls back to CPU. Set =0 to force CPU.

Don't set SLIPSTREAM_COMPOSITOR, WAYLAND_DISPLAY, or XDG_CURRENT_DESKTOP here. Pinning the compositor turns auto-detection off, per connect and mid-stream, so the host stops following session switches, and stale session values point it at dead sockets. Forcing a backend is a CI / dedicated-appliance posture, not desktop configuration.

You must be on a Wayland session (not X11), and Mutter must be ≥ 48. See the Configuration reference for every option.

The GL/EGL userspace

On NVIDIA, gnome-shell fails to start, or the host logs "GPU ... not supported by EGL", when the NVIDIA GL/EGL userspace is missing. The base driver package doesn't always pull it in. Install your distro's NVIDIA GL/EGL userspace package, on Ubuntu it's libnvidia-gl-<version> matching your driver; on Fedora/Arch it ships with the RPM Fusion / repo driver, then confirm the glvnd vendor file exists:

ls /usr/share/glvnd/egl_vendor.d/10_nvidia.json    # must exist

Installing the driver itself is covered on your distro's install page (Ubuntu, Fedora, Arch).

Do not lock the session

A locked GNOME session blocks screen capture, the host fails with "Session creation inhibited". On an always-on or headless host there's no one to unlock it, so disable the lock:

gsettings set org.gnome.desktop.screensaver lock-enabled false
gsettings set org.gnome.desktop.session idle-delay 0

Start the host

With host.env in place, start the host from inside your GNOME session:

systemctl --user enable --now slipstream-host
journalctl --user -u slipstream-host -f   # watch it come up and print its identity fingerprint

This unit runs native-only serve. To serve stock Moonlight clients, add --gamestream to the unit after confirming the host is on a trusted LAN.

A desktop-login host should also follow your session's lifetime, or restarting GNOME Shell leaves the host wired to a compositor that is gone, it keeps answering, and every session after that fails at capture. Add the drop-in from Restart the host with your desktop. Skip it on the headless route below.

Then bring up The Web Console to arm pairing and connect a client. For an always-on box, see the headless session below.

Display scaling you set while streaming sticks per client: the host remembers each device's scale and reapplies it on reconnect, see Persistent scaling.

HDR (GNOME 50+)

The per-client virtual display this page is about always streams SDR, Mutter's RecordVirtual screencasts are 8-bit upstream, so there is nothing to turn on.

GNOME 50 added HDR screencast for real monitors, and the host can use that route, on the GameStream/Moonlight plane only, by mirroring a monitor instead of creating one. HDR -> Linux + GNOME has the two settings it needs, which monitor it checks, and how it degrades when none is in HDR mode; Check it has the hdr-probe subcommand that names the link that said no.

Headless session

To run with no monitor and no login, keep a GNOME Wayland session up at all times and start the host without a login. Have GDM auto-login your user:

# /etc/gdm3/custom.conf  (Ubuntu)   ·   /etc/gdm/custom.conf  (Fedora)
[daemon]
AutomaticLoginEnable = true
AutomaticLogin = your-user

Disable the lock (see above), then enable the host user service and let it linger past logout:

systemctl --user enable --now slipstream-host
sudo loginctl enable-linger "$USER"

Reboot and the host comes up on the auto-login session. Full walkthrough: Running as a Service.

Troubleshooting

More fixes, black screen, discovery, pairing, in Troubleshooting.

Once the host is up, bring the console up and pair, see The Web Console.