Nuxt/docs/3.api/1.composables/use-state.md

title	description
useState	The useState composable creates a reactive and SSR-friendly shared state.

useState

useState<T>(init?: () => T | Ref<T>): Ref<T>
useState<T>(key: string, init?: () => T | Ref<T>): Ref<T>

• key: A unique key ensuring that data fetching is properly de-duplicated across requests. If you do not provide a key, then a key that is unique to the file and line number of the instance of useState will be generated for you.
• init: A function that provides initial value for the state when not initiated. This function can also return a Ref.
• T: (typescript only) Specify the type of state

::alert{type=warning} Because the data inside useState will be serialized to JSON, it is important that it does not contain anything that cannot be serialized, such as classes, functions or symbols. ::

::ReadMore{link="/docs/getting-started/state-management"} ::