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docs/ui/react/react-audio/src/hooks/use-preset/use-preset.md

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+# `hooks/use-preset`
+
+<!-- begin:auto-docs -->
+_(no submodules)_
+<!-- end:auto-docs -->
+
+## Purpose
+
+`usePreset(plugin)` exposes plugin-level preset operations as
+React-friendly callbacks: `get` reads the current preset, `apply`
+writes one back, and `save` / `load` persist through the provider's
+optional preset store. The hook gates `save`/`load` on the presence
+of a store; if none is configured (or if the store throws), the hook
+raises `ReactAudioError(REACT_AUDIO.PRESET_STORE_FAILED)` carrying
+the offending id and the underlying cause.
+
+## Features
+
+- `get(): PresetSnapshot` — synchronous read.
+- `apply(preset): void` — synchronous write.
+- `save(id): Promise<void>` — async write through the preset store.
+- `load(id): Promise<void>` — async read + apply.
+- Structured errors: `PRESET_STORE_FAILED` for missing store, save
+  failure, load failure, and preset-not-found.
+
+## Usage: Basic
+
+```tsx
+import { usePreset } from "@suaveplan/react-audio";
+
+function PresetButtons({ plugin }: { plugin: AudioFxPlugin }) {
+    const { save, load } = usePreset(plugin);
+    return (
+        <>
+            <button type="button" onClick={() => save("default")}>Save</button>
+            <button type="button" onClick={() => load("default")}>Load</button>
+        </>
+    );
+}
+```
+
+## Usage: Advanced
+
+```tsx
+import { usePreset } from "@suaveplan/react-audio";
+
+function ExportPreset({ plugin }: { plugin: AudioFxPlugin }) {
+    const { get } = usePreset(plugin);
+    return (
+        <button
+            type="button"
+            onClick={() => {
+                const preset = get();
+                navigator.clipboard.writeText(JSON.stringify(preset));
+            }}
+        >
+            Copy JSON
+        </button>
+    );
+}
+```
+
+## API Reference
+
+- `usePreset(plugin): { get, apply, save, load }`.
+
+## Implementation Notes
+
+The hook wraps each store interaction in a try/catch that converts
+underlying errors into `ReactAudioError(PRESET_STORE_FAILED)` with
+the original `Error` set as `cause`. The store is allowed to be
+undefined; consumers that don't need persistence omit it from
+provider options and use `get` / `apply` only. Promise rejections are
+deliberately wrapped (rather than re-thrown raw) so a single
+`error instanceof ReactAudioError` branch handles every failure path.
+The four failure modes — missing store, store-rejected save,
+store-rejected load, preset-not-found — share one code
+(`PRESET_STORE_FAILED`) but distinct `messageKey`s so an i18n layer
+can branch on the message resolver instead of the code. Non-Error
+values thrown by a store are narrowed to `undefined` causes so the
+wrapper Error remains type-safe.