---
title: 'useHydration'
description: 'Allows full control of the hydration cycle to set and receive data from the server.'
links:
  - label: Source
    icon: i-simple-icons-github
    to: https://github.com/nuxt/nuxt/blob/main/packages/nuxt/src/app/composables/hydrate.ts
    size: xs
---

`useHydration` is a built-in composable that provides a way to set data on the server side every time a new HTTP request is made and receive that data on the client side. This way `useHydration` allows you to take full control of the hydration cycle.

::callout
This is an advanced composable and is mostly used internally (`useAsyncData`) or by Nuxt modules.
::

## Type

```ts [signature]
useHydration <T> (key: string, get: () => T, set: (value: T) => void) => {}
```

You can use `useHydration()` within composables, plugins and components.

`useHydration` accepts three parameters:

- `key`: unique key that identifies the data in your Nuxt application
  - **Type**: `String`
- `get`: function that returns the value to set the initial data
  - **Type**: `Function`
- `set`: function that receives the data on the client-side
  - **Type**: `Function`

Once the initial data is returned using the `get` function on the server side, you can access that data within `nuxtApp.payload` using the unique key that is passed as the first parameter in `useHydration` composable.

:read-more{to="/docs/getting-started/data-fetching"}