Launching a game

The launch is refused outright

Message	Cause	What to do
No host available	Nothing in the fleet is online, or no host could ever serve the request.	Check Admin, Fleet, Hosts. Retrying will not help.
Capacity exhausted	Hosts are up but currently full on encode slots or GPU memory.	Retry once something ends.
Session quota exceeded	The user is at their concurrent session limit.	End one, or raise the limit in Admin, People, Users. Note that a limit of zero blocks everything.
Home in use	The user already has this app running elsewhere. The response names the session.	End that session. One session per user per app, because two writers corrupt save files.
Not entitled	No grant for this user and app.	Grant it in Admin, Library, Apps.

Capacity looks free but launches are refused

Admission needs both a free encode slot and enough free GPU memory. The memory check is a veto against the most recent telemetry sample, defaulting to 1024 MB free.

On a machine with a small GPU memory carve-out, particularly an integrated GPU, that floor can be more than the GPU ever has free. The veto is designed to abstain when the telemetry is structurally implausible, but if you are seeing refusals on a host with capacity, lower the floor:

QUASAR_VRAM_MIN_FREE_MB=512

Or disable the veto and admit on slots alone:

QUASAR_VRAM_MIN_FREE_MB=0

The session starts, then fails immediately

The app container exited. The agent watches for this now rather than leaving you streaming a frozen frame.

Check the session detail in Admin, Sessions for the exit reason, and check the app container’s own logs.

Common causes:

The app needs network access and does not have it. App containers get no network by default. Anything that phones home on first launch exits cleanly and you get an unhelpful message about the media path. Set network: bridge on the runtime preset for that app.

The image is not from the Quasar image family. An app image must derive from the project’s graphics base layer, which is what provides GPU access and the Wayland and audio plumbing. An arbitrary public image will not work.

The app genuinely crashed. Its own logs.

The session stays running but shows a frozen frame

This used to happen when a container exited without the agent noticing. Liveness monitoring now catches it and fails the session.

If you are seeing it, check the app’s exit policy. keep deliberately holds the session open when the app exits. fail is the default and usually what you want.

Steam will not start

“Steam needs to be” in the agent log means Steam could not launch. Almost always no network. Steam downloads part of its own interface on first launch. Set network: bridge on the Steam runtime preset.

Steam starts but no games are discovered. Discovery scans the filesystem for installed games. It does not sync what you own. Install something through the Steam launcher app first, then wait for the next scan or trigger one from Admin, Steam.

Discovery needs a managed-home root on the selected host. If the host has no effective storage root, set one under Admin, Fleet, Hosts. A root that exists only inside the agent container is also wrong: it must be the bind-mounted host path.

The Steam image will not install. The published package is public, so inspect the install job under Admin, Fleet, Jobs. Common causes are registry reachability, a registry outside QUASAR_IMAGE_REGISTRY_HOSTS, or an image contract failure.

The game runs at the wrong resolution

Quasar injects the session’s resolution and frame rate into the container as QUASAR_STREAM_WIDTH, QUASAR_STREAM_HEIGHT and QUASAR_STREAM_FPS, plus GAMESCOPE_* equivalents for images that bake in gamescope defaults.

If an app is ignoring them, check whether its runtime preset sets those variables explicitly. An explicit value wins over the injected one.

Without this, an image built for 1080p60 renders at 1080p60 even in a 1440p120 session, and the result is upscaled into the stream, spending your bitrate on interpolated detail.

Nothing is in the library

Check entitlements first. A user only sees apps they are granted. Library discovery grants to everyone automatically, apps you create by hand do not.

Then check the app exists in Admin, Library, Apps at all.

Controllers are not detected

Press a button. Browsers do not reveal a gamepad until it has sent input.

Then confirm the page is on HTTPS, since the Gamepad API needs a secure context.

Then check /dev/uinput on the host is present and writable by the agent. A read-only open succeeds even when it is broken, which makes this easy to misdiagnose. The host readiness check tests writing.

Big Picture mode and the first controller event

Steam’s Big Picture interface can start without keyboard or controller focus. The agent nudges focus on the first gamepad event to work around it. If the interface seems unresponsive on entry, press a button.