UI sounds

Every interactive action ships with audio feedback out of the box — a curated sound palette (cuelume, MIT), vendored into the repo rather than installed as a dependency. No package.json entry, no go.mod entry, no network fetch at build or runtime. Sounds are synthesized live with the Web Audio API — there are no audio files.

It's a plugin, not baked into the app

The plugin (features/sounds/) owns its whole surface:

the script loader (@sounds.SoundAssets() in each page's <head>),
the navbar mute toggle (@sounds.SoundToggle()),
the client glue (web/resources/static/cuelume.js).

The glue ships the sound accessibility contract out of the box.

The accessibility contract

prefers-reduced-motion respected by default. OS-level reduced motion auto-mutes playback and reacts to runtime preference changes. There is no in-app override — it's an accessibility setting, not a preference.
Global mute with a real control. The navbar 🔊 button toggles sound on/off, persists the choice in localStorage (key gogogo_sound), is keyboard-accessible (aria-pressed on a real <button>), and survives Datastar DOM morphs (delegated click, same pattern as theme.js). The button always reflects and responds to the user's own choice — if reduced-motion keeps playback muted anyway, the button still flips and its tooltip explains the system override, so it never looks dead.
Subtle default volume. cuelume's mixer runs hotter than libraries tuned for a 30% default; DEFAULT_VOLUME (0.4) keeps every cue audible without being intrusive. Tune it in cuelume.js.
Sounds are additive only. Every cue pairs with existing visual feedback (toasts, button states, spinners) and never replaces it.

Behavior wiring

bind() enables declarative data-cuelume-* attributes (data-cuelume-press, -release, -hover, -toggle) anywhere, so per-element sounds work without touching the glue.

Global press sound — a delegated pointerdown listener plays the press knock on every button, role="button"/role="tab", .btn link, and checkbox. It works on mouse, touch, and pen (pointer events) and covers Datastar-morphed DOM.

Toast-type chimes — a MutationObserver on #toast-container plays a cue matching the toast type:

Toast class	Cue
`alert-success`	`success`
`alert-error`	`error`
`alert-warning`	`loading` — cuelume has no dedicated warning cue, so the rising shimmer reads as "still working"
`alert-info`	`page`

No server changes needed: the existing SSE toast path (create, delete, clear, workflow completion, retry/Suggest failures) feeds the sounds.

window.Cuelume is a tiny public API (play, setEnabled, setVolume, isEnabled) for future settings surfaces.

Customizing

Since cuelume is client-side only, your app owns the settings:

import { play, setVolume } from "/static/cuelume/index.js";

play("sparkle");   // play any of the 14 sounds imperatively
setVolume(0.6);    // global volume, clamped to 0–1 (default 0.4)

To add a per-element sound, drop a data-cuelume-* attribute on the element — bind() picks it up automatically, including elements added by Datastar later.

Update and remove

Update: re-download cuelume's dist/ into web/resources/static/cuelume/ (keep the LICENSE).

Remove: delete features/sounds/, drop @sounds.SoundAssets() from the page layouts and @sounds.SoundToggle() from the navbar, then delete web/resources/static/cuelume.js and web/resources/static/cuelume/. The full checklist lives in the SCOPE:plugin doc comment in features/sounds/sounds.go.

UI skins — the other pluggable UI surface.