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The QAM already offered a client update — for the flatpak, by comparing OSTree commits. A native client (.deb, .rpm, pacman, sysext, nix, a source build), which the plugin has been able to LAUNCH since it learned to drive one, went stale in silence: no version, no check, no mention. check_update now branches on the client the launcher will actually run. The flatpak keeps its commit comparison, which is the exact one — a flatpak built from main between releases carries the release's crate version, so a version-based check would call it current when it isn't. Everything else asks the client itself, which verifies the signed manifest. update_client routes the same way: flatpak update --user, or `punktfunk-client --apply-update`. Where nothing on the box can install it, the plugin says so instead of offering a button. The QAM banner becomes the command, the About tab names the install kind so "why is there no Update button?" has a visible answer, and a check that FAILED reads as a failure — never as "up to date". Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Punktfunk — Steam Deck plugin (Decky)
Stream to your Steam Deck without ever leaving Gaming Mode. This
Decky Loader plugin adds a Punktfunk panel to the Quick Access Menu
(the … button): discover hosts on your network, pair with a PIN, tweak stream settings, and launch
a fullscreen, gamescope-focused stream — all from the couch, gamepad-navigable.
The video itself is the native GTK4 Linux client (the io.unom.Punktfunk flatpak); the plugin
discovers, pairs, configures, and launches it the right way so gamescope fullscreens it — the same
Steam-shortcut trick MoonDeck uses. Because it's built from real Steam UI primitives (@decky/ui),
the panel looks and feels native to Gaming Mode.
What it does
- Discover — browses the LAN over mDNS for Punktfunk hosts, in both the QAM panel and a fullscreen page; each host row opens a details view (address, pairing policy, certificate fingerprint to cross-check against the host's log).
- Pair — for a host that requires it, a gamepad-navigable PIN keypad runs the SPAKE2 pairing ceremony headlessly, then remembers the host so future streams connect silently.
- Stream — launches fullscreen via a branded "Punktfunk" Steam shortcut so gamescope focuses it.
- Games — each host row has a games button that opens its library picker: pin titles as one-tap "Stream " rows in the QAM (jump straight into e.g. Playnite on the host), or "Open library on screen" to launch the client's controller-driven, console-style library browser (aurora backdrop + poster coverflow; A plays, B returns to Gaming Mode). Pins survive plugin reinstalls (stored next to the client's config) and follow a host across IP changes (matched by certificate fingerprint).
- Settings — resolution / refresh / bitrate / gamepad type / host compositor / mic, written to the client's config.
- About — plugin version, an explicit "Check for updates" button, the setup-guide link, and a force-stop for a wedged stream client.
To leave a stream: the in-client controller chord (L1 + R1 + Start + Select), or close the "game" from the Steam overlay — either returns you to Gaming Mode.
Install on the Deck
You need Decky Loader and the io.unom.Punktfunk flatpak
(packaging/flatpak) installed on the Deck — SteamOS /usr is
read-only, so the flatpak (which bundles libadwaita/SDL3) is the canonical client. Discovery uses
avahi-browse, which ships on SteamOS/Bazzite.
Recommended — install from URL (published by CI): in Decky → Settings → Developer Mode → Install Plugin from URL, paste:
https://unom.io/pf-decky
(short link for https://git.unom.io/api/packages/unom/generic/punktfunk-decky/latest/punktfunk.zip;
for a pinned version use https://git.unom.io/api/packages/unom/generic/punktfunk-decky/<version>/punktfunk.zip
directly). The plugin then self-updates without
the Decky store — when a newer build exists, an Update button appears and drives Decky
Loader's own (SHA-256-verified) install. Installs and updates can take a couple of minutes on some
networks: Decky's installer also contacts its plugin store first, which may be slow or blackholed
before the actual download proceeds.
Updating the client
The plugin also reports — and where it can, installs — updates for the client it launches. What is possible depends on how that client was installed, and the About tab names the install kind so the answer is never a mystery:
| Install | Update |
|---|---|
| Flatpak (the usual Deck client) | One tap. flatpak update --user io.unom.Punktfunk — a per-user install, which is why sudo flatpak update never touches it. |
| .deb / .rpm (and rpm-ostree, which stages for the next reboot) | One tap, after an explicit opt-in: sudo usermod -aG punktfunk-update $USER. The tap starts a fixed, parameterless root oneshot (punktfunk-client-update.service) through polkit — nothing about the request is attacker-influenceable, and the payload comes from your distro's own signed repositories. |
| pacman | Same, plus the root-owned PACMAN_FULL_SYSUPGRADE=1 in /etc/punktfunk/update.conf — a partial upgrade is against Arch doctrine, so the only thing the helper will run is a full pacman -Syu. |
| sysext, nix, a source build | The plugin shows the command and stops. There is no feed behind those installs, and a button that can only fail is worse than one honest line. |
Whether a newer client exists is the client's own answer (punktfunk-client --check-update),
read from the Ed25519-signed per-channel manifest the host's update check already trusts —
PUNKTFUNK_UPDATE_CHECK=0 disables the check, PUNKTFUNK_UPDATE_APPLY=0 keeps the check but
never offers to install. A client too old to have that mode is reported as such rather than as
up to date.
Build & sideload (development)
cd clients/decky
pnpm install
pnpm build # rollup → dist/index.js
pnpm run package # → out/punktfunk/ + out/punktfunk-v<ver>.zip
DECK=deck@<deck-ip> pnpm run deploy # rsync → /tmp, sudo-install into the root-owned plugins dir, restart loader
~/homebrew/plugins/ is root-owned (the loader runs as root), so deploy.sh stages to a temp dir
then sudo-installs and restarts the loader — set DECKPASS=… to run it non-interactively. A loader
restart is required for an out-of-band install to appear.
Architecture
| File | Role |
|---|---|
src/index.tsx |
Plugin entry: the QAM panel + route registration. |
src/page.tsx |
The /punktfunk fullscreen page — Hosts (with per-host details) / Settings / About tabs. |
src/settings.tsx · src/pair.tsx |
Stream-settings section; the gamepad-navigable PIN-pairing modal. |
src/library.tsx |
The per-host game picker (pin/unpin, "Open library on screen") + the pinned-game launch helper. |
src/hostmgmt.tsx |
Add / edit host dialogs — mutate the shared known-hosts store (client-known-hosts.json) via the flatpak client's headless modes, so a host saved here shows up in the desktop client too. |
src/ui.tsx |
Shared UI primitives for the fullscreen page + modals (right-aligned row actions, consistent Field layout). |
src/hooks.ts · src/boundary.tsx |
Shared discovery/update/pins hooks + actions; the render error boundary. |
src/steam.ts |
Steam-shortcut launch (AddShortcut / SetAppLaunchOptions / RunGame) — the focus-correct stream start. The shortcut's exe is /bin/sh with the wrapper passed as an argument, so the script never needs an exec bit (Decky's zip extraction drops it and the root-owned plugins dir can't be chmodded by the unprivileged backend). Launch extras ride env-prefix tokens: PF_LAUNCH=<id> (pinned game) / PF_BROWSE=1 + PF_MGMT=<port> (on-screen library); ids are validated space/quote-free at pin AND launch time. |
src/backend.ts |
Typed callable bridges to main.py. |
bin/punktfunkrun.sh |
The launch wrapper the Steam shortcut runs (so the window is focusable); maps PF_LAUNCH/PF_BROWSE/PF_MGMT to --launch/--browse/--mgmt. An older flatpak ignores the flags harmlessly (plain stream / hosts page). |
main.py |
Backend: discover (via avahi-browse) / pair / library (headless flatpak --library, TSV) / pins store (decky-pinned.json) / settings / kill_stream / check_update (with an explicit CA-bundle search — Decky's embedded Python has no usable default TLS roots on SteamOS). |
scripts/test-backend.py |
Stdlib-only checks for the backend's pure parsers (TSV, error classes, avahi TXT) + the pins round trip. |
plugin.json · update.json |
Decky manifest; CI-baked update channel. |
Limitations / next steps
- No manual "add host by IP" entry yet (discovery is mDNS-only).
- No in-stream overlay inside the plugin — the client owns the session once launched.
- Pairing needs the operator to arm pairing on the host so it shows the PIN; the plugin can't arm it remotely.
Related
- Documentation — Steam Deck setup guide
- Linux client — the app this plugin launches
- Project README — the host, the other clients, and how it all fits together