react-query/docs/framework/svelte/overview.md

metadata

id: overview
title: Overview

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

Example

Include the QueryClientProvider near the root of your project:

<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:

<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.

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
• 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.

• Many of the functions in Svelte Query return a Svelte store. To access values on these stores reactively, you need to prefix the store with a $. You can learn more about Svelte stores here.
• If your query or mutation depends on variables, you must use a store for the options. You can read more about this here.