# Overview

The `@tanstack/svelte-query` package offers a 1st-class API for using TanStack Query via Svelte.

> Migrating from stores to the runes syntax? See the [migration guide](./migrate-from-v5-to-v6).

## Example

Include the QueryClientProvider near the root of your project:

```svelte
<script lang="ts">
  import { QueryClient, QueryClientProvider } from '@tanstack/svelte-query'
  import Example from './lib/Example.svelte'

  const queryClient = new QueryClient()
</script>

<QueryClientProvider client={queryClient}>
  <Example />
</QueryClientProvider>
```

Then call any function (e.g. createQuery) from any component:

```svelte
<script lang="ts">
  import { createQuery } from '@tanstack/svelte-query'

  const query = createQuery(() => ({
    queryKey: ['todos'],
    queryFn: () => fetchTodos(),
  }))
</script>

<div>
  {#if query.isLoading}
    <p>Loading...</p>
  {:else if query.isError}
    <p>Error: {query.error.message}</p>
  {:else if query.isSuccess}
    {#each query.data as todo}
      <p>{todo.title}</p>
    {/each}
  {/if}
</div>
```

## SvelteKit

If you are using SvelteKit, please have a look at [SSR & SvelteKit](./ssr).

## Available Functions

Svelte Query offers useful functions and components that will make managing server state in Svelte apps easier.

- `createQuery`
- `createQueries`
- `createInfiniteQuery`
- `createMutation`
- `useQueryClient`
- `useIsFetching`
- `useIsMutating`
- `useMutationState`
- `useIsRestoring`
- `useHydrate`
- `<QueryClientProvider>`
- `<HydrationBoundary>`

## Important Differences between Svelte Query & React Query

Svelte Query offers an API similar to React Query, but there are some key differences to be mindful of.

- The arguments to the `create*` functions must be wrapped in a function to preserve reactivity.