Chromium with WebXR for the Steam Frame

A build recipe and installer for Chromium with immersive WebXR on Valve's Steam Frame headset. Press the Enter VR button on a WebXR site and it opens in the headset, through SteamVR, as a full VR experience.

The Chromium that SteamOS offers (Flathub) can't do this. Websites see navigator.xr, but isSessionSupported("immersive-vr") returns false, so VR buttons are greyed out or missing. Upstream Chromium only wires up its OpenXR backend on Windows and Android. This repo builds Chromium with the in-progress Linux OpenXR changes, adds a small fix so it works with SteamVR, and installs it on the Frame as a normal app in your Steam library.

What you can do with it

The web has a lot of VR content that only needs a browser:

• 360° and 3D video. Travel, nature, concerts, sports and documentaries from players that support WebXR, shown around you instead of in a flat window.
• Games and toys. WebXR games and experiments made with three.js, A-Frame or Babylon.js, with nothing to install.
• Learning. Virtual museum tours, space and anatomy explorers, and other educational experiences built for the web.
• Art and music. Painting, sculpting and music toys that run in a page.
• Building WebXR sites. Test your own WebXR app on real headset hardware from a normal URL, with Chromium's DevTools.

Status

Tested on a Steam Frame (SteamOS 0.3.0, build 20260922.6101926, SteamVR 2.17.10) with Chromium 156.0.8071.0, built for arm64:

isSessionSupported("immersive-vr")	true
WebXR Samples Immersive VR Session	shows its scene in the headset
three.js stereo 360 video	plays in 3D
Launch from the Steam library	opens as its own panel, like any app; WebXR renders in the headset
Controllers inside WebXR pages	tracked pose every frame; squeeze events and button state reach the page (trigger, thumbstick and left controller not tested)
Frame rate	72 fps, every frame 13.9–14 ms over 16 s (simple scene); SteamVR dropped frames only at startup

This is an unofficial, experimental build. See Limitations before you use it for anything other than VR sites.

Requirements

• A Steam Frame with SteamVR, and a way to run commands on it: the terminal in Desktop Mode, or SSH.
• To build: an x86-64 Linux machine with about 90 GB free disk, git, Python 3, tmux (or another way to keep a long job running) and a few hours. No root access is needed. The first build took about 9.5 hours on a 6-core, 12-thread desktop CPU; rebuilds take minutes.

Build

On the Linux build machine:

git clone https://github.com/saphid/chromium-webxr-steam-frame
cd chromium-webxr-steam-frame
mkdir -p ~/chromium-xr
tmux new -d -s chromium-xr 'build/build.sh > ~/chromium-xr/build.log 2>&1'

build.sh fetches Chromium with the Linux OpenXR changes, applies the patch in patches/, cross-compiles for arm64 and packs the result into ~/chromium-xr/chromium-xr-arm64.tar.xz (about 145 MB).

• Follow progress with tail -F ~/chromium-xr/stage (milestones) or tail -F ~/chromium-xr/build.log (everything).
• If it stops (reboot, full disk, network), run the same command again. It picks up where it left off.
• To build on another disk, set CHROMIUM_XR_DIR and use that directory in place of ~/chromium-xr in the commands above, including the log path.
• It stops itself if free disk space drops below 12 GB.

Install on the Frame

Copy the tarball and this repo to the Frame, then run the installer there. For example, over SSH from the build machine (replace steamframe with your Frame's hostname or IP address):

scp ~/chromium-xr/chromium-xr-arm64.tar.xz steamos@steamframe:
ssh steamos@steamframe
git clone https://github.com/saphid/chromium-webxr-steam-frame
chromium-webxr-steam-frame/frame/install.sh ~/chromium-xr-arm64.tar.xz

The installer:

• unpacks the build into ~/chromium-xr, after checking the new binary runs;
• installs the chromium-xr launcher in ~/.local/bin;
• adds Chromium XR to the Desktop Mode app menu;
• adds Chromium XR to your Steam library, without restarting Steam.

Run it again with a newer tarball to update. Your profile (~/.config/chromium-xr) and the Steam shortcut are kept. You can delete the repo clone afterwards; the installer keeps what it needs to uninstall.

If the Steam shortcut can't be added automatically, add it by hand: in Desktop Mode, open Steam, choose Games → Add a Non-Steam Game to My Library, and pick Chromium XR.

Use it

1. Open Chromium XR from your Steam library. It appears as a panel in the headset.
2. Go to a WebXR site, for example the WebXR Samples.
3. Press the site's Enter VR button.
4. Chromium asks Allow VR? in the browser panel. Choose Allow this time or Allow while visiting the site.
5. To leave VR, use the site's exit button or the Steam button.

The first time you launch it, Steam may show an External Controller Translation notice. It's only information about controller button icons; choose OK.

From a terminal on the Frame, chromium-xr https://example.com opens a page directly.

Limitations

• Part of the sandbox is off. The launcher passes --disable-seccomp-filter-sandbox, which turns off Chrome's system-call filter for every process; the namespace sandbox stays on. Without it, SteamVR refuses the session (details in docs/technical-notes.md). Use Chromium XR for VR sites and keep another browser for everyday browsing.
• Saved passwords aren't encrypted. The launcher uses --password-store=basic so startup doesn't stop at a keyring prompt, so passwords you save are stored unencrypted in ~/.config/chromium-xr.
• No automatic updates. It won't get Chromium security fixes until you rebuild it.
• No controller vibration. SteamVR reports no haptic actuators to the page.
• No DRM video. There's no Widevine, so paid streaming services that need it won't play.
• One window at a time per profile. If Chromium XR is already open, launching it again opens the page in the existing window.
• Not a default browser. It works as one (the desktop entry registers for web links), but for the reasons above it's better kept for VR.

Remove it

~/.local/share/chromium-xr/uninstall.sh                   # keeps your profile
~/.local/share/chromium-xr/uninstall.sh --remove-profile  # also deletes settings and logins

This removes the build, the launcher, the menu entry and the Steam shortcut.

Updating

The Chromium changes are still under review upstream, so this repo pins one revision of them (CL_REF in build/build.sh, currently patch set 44 of CL 8132979). To build a newer patch set, set CL_REF when you run the build, for example CL_REF=refs/changes/79/8132979/45 build/build.sh. The script fetches it, syncs, re-applies the local patch and rebuilds. A newer patch set may need the patch in patches/ updated. Then install the new tarball on the Frame as above.

How it works

• Chromium changes. CL 8441736 (a sandboxed XR process on Linux) and CL 8132979 (the OpenXR device provider on Linux, patch set 44), tracked in Chromium issue 506004811. CL 8441736 has since merged; CL 8132979 is still in review. The OpenXR device is behind --enable-features=OpenXR, which the launcher passes.
• SteamVR fix. SteamVR's OpenXR runtime asks the kernel who is on the other end of its socket (getsockopt(SO_PEERCRED)). The XR sandbox policy blocks all getsockopt calls, which crashed the XR process. patches/0001-… allows only that one option. It's reported upstream, with the seccomp issue below, in utzcoz/chromium-webxr-linux#7.
• Steam integration. frame/steam-shortcut.py adds the shortcut through the Steam client's local DevTools port, the same API the Steam UI uses. Steam runs each app as its own panel, so Chromium gets one too.

More detail, including why the seccomp filter is off, is in docs/technical-notes.md.

Related work

• utzcoz/chromium-webxr-linux: a fuller patch series for WebXR over OpenXR on Linux desktops, including the in-headset permission UI and crash fixes, tested with Monado. If you're on an x86-64 Linux PC rather than the Steam Frame, start there.
• Chromium issue 506004811: upstream tracking for WebXR on Linux.

License

The scripts in this repo are under the BSD 3-Clause License. The patch in patches/ modifies Chromium and is under Chromium's license. Chromium is a trademark of Google LLC; this project is not affiliated with Google or Valve.