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packages/hooks/src/useMounted/Readme.md

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+# useMounted
+
+Returns `true` after the component has mounted on the client. Useful for deferring client-only rendering to avoid SSR hydration mismatches.
+
+## Signature
+
+```ts
+function useMounted(): boolean;
+```
+
+## Usage
+
+```tsx
+function ThemeToggle() {
+  const mounted = useMounted();
+
+  if (!mounted) return null; // avoid SSR/hydration mismatch
+
+  return <button>{getCurrentTheme()}</button>;
+}
+```
+
+## Notes
+
+- Always returns `false` on the first render (SSR and initial client render), then `true` after `useEffect` fires.
+- Client-only (`'use client'`).