Add Audio Output Switcher to Plugin Store

[zomars]

Add Audio Output Switcher to Plugin Store

Audio Output Switcher lets you change the default audio output device directly from the Quick Access Menu, without a trip to desktop mode. This is especially useful on devices where gamemode has no output picker at all — e.g. on a Steam Machine driving a TV, the QAM audio section is only a CEC volume slider.

What it does:

• Lists every available audio output, with the active device marked and pinned to the top.
• Switches the output with one tap, and already-playing streams follow the switch immediately rather than only new ones.
• Adds a "Follow system default" row while an override is set, so there is a way back from a pinned device.
• Optional controller shortcut: a button combo you record yourself cycles the output without opening the panel. Nothing is bound by default.
• Device arrival and removal are events, so a wireless headset connecting or powering off shows up right away without reloading the panel.

The backend is the standard Python backend and declares no flags, so it runs as the ordinary user rather than root — no bundled binaries and no subprocesses. Switching goes through SteamClient.System.Audio, the same API Steam's own audio selector uses; the Python side exists only to persist the shortcut binding across restarts.

Submodule is pinned at ff2cc4b (v1.2.0).

Task Checklist

Developer

• I am the original author or an authorized maintainer of this plugin.
• I have abided by the licenses of the libraries I am utilizing, including attaching license notices where appropriate.
• Generative AI was NOT used to write a majority of the code I am submitting.

Plugin

• I have verified that my plugin works properly on the Stable and Beta update channels of SteamOS.
• I have verified my plugin is unique or provides more/alternative functionality to a plugin already on the store.

Backend

• No: I am using a custom backend other than Python.
• No: I am using a tool or software from a 3rd party FOSS project that does not have it's dependencies statically linked.
• No: I am using a custom binary that has all of it's dependencies statically linked.

Community

• I have tested and left feedback on two other pull requests for new or updating plugins.
• I have commented links to my testing report in this PR.

Testing

• Tested by a third party on SteamOS Stable or Beta update channel.

[github-actions]

Issues Found

• Neither testing box is present in your description. Please include one of them per the Markdown comment above the testing section.

Next Steps

1. If we found any issues above, please edit your pull request description to resolve them and leave a comment saying you've done so.
2. For the quickest review, please see the Community section of the pull request template for how you can help other developers.
3. Once your description is correct, a maintainer will review your pull request as soon as possible.

Thank you for your contribution! If you need any help, please reach out on our Discord server. ❤️

[github-actions]

This pull request is stale as no updates or testing reports have been posted within the last 7 days. Please ensure you are actively recruiting testers or resolving the issues discussed. If you do not remove the stale label or comment, this will be closed in 7 days. Please close this pull request if you need more time to resolve issues so we can keep our repo healthy.

[zomars]

Testing reports I left on other plugin pull requests, per the Community checklist:

• #1106 — Update Bluetooth to v3.0.0 — built from the submodule commit and verified it reproduces the release artifact, then tested the D-Bus rewrite against a controller and a set of earbuds.
• #1104 — Add Decky SSH to Plugin Store — verified the root flag, the systemd toggle and the PAM-based current-password check.

Both were tested on SteamOS Stable with Decky Loader 3.2.6.

[github-actions]

This pull request is stale as no updates or testing reports have been posted within the last 7 days. Please ensure you are actively recruiting testers or resolving the issues discussed. If you do not remove the stale label or comment, this will be closed in 7 days. Please close this pull request if you need more time to resolve issues so we can keep our repo healthy.

[zomars]

Pin updated to v1.2.0 (ff2cc4b); description updated to match.

Switching now goes through SteamClient.System.Audio instead of pactl:

• Playing streams follow the switch, handled by Steam.
• Virtual sinks such as steam-streaming-playback are no longer listed.
• Device add/remove are events, not a four-second poll.
• New "Follow system default" row clears an override.
• The Python backend only persists the shortcut binding; no subprocesses.

Still needs a third-party tester. Build plugin (AudioOutputSwitcher, true) has been waiting for maintainer approval since 18 Aug, so there is no CI build to install.

[Outpox]

Testing report

Tested on a Steam Deck LCD, SteamOS Stable, Decky Loader v3.2.6, at the pinned commit ff2cc4b.

Built it from source: pnpm build and tsc --noEmit are clean, and the rebuilt dist/index.js is
byte-identical to the committed one. Installed it and drove the panel on hardware.

What worked

• Switching outputs from the panel. pactl get-default-sink followed every tap, and a live audio
  stream moved across with it, no manual move-sink-input needed. That part is genuinely nice.
• "Follow system default" appears only when an override is set, clears it correctly, and disappears again.
• Device add and remove are live. I removed a sink with the panel open and it vanished without a reload.
• Backend loads and unloads cleanly, nothing in the logs, no root needed.

Three things I would fix

1. Closing the panel mid-capture leaves the capture armed. Nothing clears the capture global
   on unmount. Start recording a combo, close the QAM with the … button (which by your own README
   never reaches the input stream), and the panel looks idle on reopen but is not: the shortcut
   stops firing, and the next two buttons held together in a game get saved as the new binding.
   I reproduced it with your own onButton / startCapture code: a saved L4+R4 binding silently
   became A+B. Clearing capture in the effect cleanup, plus a timeout, should cover it.

2. On a plain Deck with nothing plugged in, the panel shows one disabled row and no explanation.
   PipeWire exposes Speaker and Headphones as separate sinks, but Steam collapses them into a single
   device, so SetDefaultDeviceOverride cannot reach that distinction. Your Steam Machine case is
   real and the README explains it well, but publish.description promises "every available audio
   output", which reads wrong on the device most store users own. Worth naming the audience in the
   description, and showing a line like "Only one output available, connect a headset, dock or TV"
   instead of a bare disabled row.

3. The active device is not pinned to the top, contrary to the PR body and README. It is marked
   with ●, but the list is sorted alphabetically only. With a second device active it sat third.
   Either implement it or drop the claim. Note cycleOutput walks the same array, so pinning would
   change the shortcut's cycle order too.

Smaller stuff: the README still says "repolls" in the features list where the code uses events, and
plain virtual sinks do show up in GetDevices() (two module-null-sink sinks appeared with
bHasOutput: true), so the "virtual sinks never appear" note is stated more strongly than it holds.