QueryClient

The QueryClient can be used to interact with a cache:

import { QueryClient } from '@tanstack/react-query'

const queryClient = new QueryClient({
  defaultOptions: {
    queries: {
      staleTime: Infinity,
    },
  },
})

await queryClient.prefetchQuery({ queryKey: ['posts'], queryFn: fetchPosts })

Its available methods are:

• queryClient.fetchQuery
• queryClient.fetchInfiniteQuery
• queryClient.prefetchQuery
• queryClient.prefetchInfiniteQuery
• queryClient.getQueryData
• queryClient.ensureQueryData
• queryClient.getQueriesData
• queryClient.setQueryData
• queryClient.getQueryState
• queryClient.setQueriesData
• queryClient.invalidateQueries
• queryClient.refetchQueries
• queryClient.cancelQueries
• queryClient.removeQueries
• queryClient.resetQueries
• queryClient.isFetching
• queryClient.isMutating
• queryClient.getDefaultOptions
• queryClient.setDefaultOptions
• queryClient.getQueryDefaults
• queryClient.setQueryDefaults
• queryClient.getMutationDefaults
• queryClient.setMutationDefaults
• queryClient.getQueryCache
• queryClient.getMutationCache
• queryClient.clear
• queryClient.resumePausedMutations

Options

• queryCache?: QueryCache
  • Optional
  • The query cache this client is connected to.
• mutationCache?: MutationCache
  • Optional
  • The mutation cache this client is connected to.
• defaultOptions?: DefaultOptions
  • Optional
  • Define defaults for all queries and mutations using this queryClient.

fetchQuery is an asynchronous method that can be used to fetch and cache a query. It will either resolve with the data or throw with the error. Use the prefetchQuery method if you just want to fetch a query without needing the result.

If the query exists and the data is not invalidated or older than the given staleTime, then the data from the cache will be returned. Otherwise it will try to fetch the latest data.

The difference between using fetchQuery and setQueryData is that fetchQuery is async and will ensure that duplicate requests for this query are not created with useQuery instances for the same query are rendered while the data is fetching.

try {
  const data = await queryClient.fetchQuery({ queryKey, queryFn })
} catch (error) {
  console.log(error)
}

Specify a staleTime to only fetch when the data is older than a certain amount of time:

try {
  const data = await queryClient.fetchQuery({
    queryKey,
    queryFn,
    staleTime: 10000,
  })
} catch (error) {
  console.log(error)
}

Options

The options for fetchQuery are exactly the same as those of useQuery, except the following: enabled, refetchInterval, refetchIntervalInBackground, refetchOnWindowFocus, refetchOnReconnect, refetchOnMount, notifyOnChangeProps, throwOnError, select, suspense, placeholderData; which are strictly for useQuery and useInfiniteQuery. You can check the source code for more clarity.

Returns

• Promise<TData>

fetchInfiniteQuery is similar to fetchQuery but can be used to fetch and cache an infinite query.

try {
  const data = await queryClient.fetchInfiniteQuery({ queryKey, queryFn })
  console.log(data.pages)
} catch (error) {
  console.log(error)
}

Options

The options for fetchInfiniteQuery are exactly the same as those of fetchQuery.

Returns

• Promise<InfiniteData<TData, TPageParam>>

prefetchQuery is an asynchronous method that can be used to prefetch a query before it is needed or rendered with useQuery and friends. The method works the same as fetchQuery except that it will not throw or return any data.

await queryClient.prefetchQuery({ queryKey, queryFn })

You can even use it with a default queryFn in your config!

await queryClient.prefetchQuery({ queryKey })

Options

The options for prefetchQuery are exactly the same as those of fetchQuery.

Returns

• Promise<void>
  • A promise is returned that will either immediately resolve if no fetch is needed or after the query has been executed. It will not return any data or throw any errors.

prefetchInfiniteQuery is similar to prefetchQuery but can be used to prefetch and cache an infinite query.

await queryClient.prefetchInfiniteQuery({ queryKey, queryFn })

Options

The options for prefetchInfiniteQuery are exactly the same as those of fetchQuery.

Returns

• Promise<void>
  • A promise is returned that will either immediately resolve if no fetch is needed or after the query has been executed. It will not return any data or throw any errors.

getQueryData is a synchronous function that can be used to get an existing query's cached data. If the query does not exist, undefined will be returned.

const data = queryClient.getQueryData(queryKey)

Options

• queryKey: QueryKey: Query Keys

Returns

• data: TQueryFnData | undefined
  • The data for the cached query, or undefined if the query does not exist.

ensureQueryData is an asynchronous function that can be used to get an existing query's cached data. If the query does not exist, queryClient.fetchQuery will be called and its results returned.

const data = await queryClient.ensureQueryData({ queryKey, queryFn })

Options

• the same options as fetchQuery
• revalidateIfStale: boolean
  • Optional
  • Defaults to false
  • If set to true, stale data will be refetched in the background, but cached data will be returned immediately.

Returns

• Promise<TData>

getQueriesData is a synchronous function that can be used to get the cached data of multiple queries. Only queries that match the passed queryKey or queryFilter will be returned. If there are no matching queries, an empty array will be returned.

const data = queryClient.getQueriesData(filters)

Options

• filters: QueryFilters: Query Filters
  • if a filter is passed, the data with queryKeys matching the filter will be returned

Returns

• [queryKey: QueryKey, data: TQueryFnData | undefined][]
  • An array of tuples for the matched query keys, or [] if there are no matches. The tuples are the query key and its associated data.

Caveats

Because the returned data in each tuple can be of varying structures (i.e. using a filter to return "active" queries can return different data types), the TData generic defaults to unknown. If you provide a more specific type to TData it is assumed that you are certain each tuple's data entry is all the same type.

This distinction is more a "convenience" for ts devs that know which structure will be returned.

setQueryData is a synchronous function that can be used to immediately update a query's cached data. If the query does not exist, it will be created. If the query is not utilized by a query hook in the default gcTime of 5 minutes, the query will be garbage collected. To update multiple queries at once and match query keys partially, you need to use queryClient.setQueriesData instead.

The difference between using setQueryData and fetchQuery is that setQueryData is sync and assumes that you already synchronously have the data available. If you need to fetch the data asynchronously, it's suggested that you either refetch the query key or use fetchQuery to handle the asynchronous fetch.

queryClient.setQueryData(queryKey, updater)

Options

• queryKey: QueryKey: Query Keys
• updater: TQueryFnData | undefined | ((oldData: TQueryFnData | undefined) => TQueryFnData | undefined)
  • If non-function is passed, the data will be updated to this value
  • If a function is passed, it will receive the old data value and be expected to return a new one.

Using an updater value

setQueryData(queryKey, newData)

If the value is undefined, the query data is not updated.

Using an updater function

For convenience in syntax, you can also pass an updater function which receives the current data value and returns the new one:

setQueryData(queryKey, (oldData) => newData)

If the updater function returns undefined, the query data will not be updated. If the updater function receives undefined as input, you can return undefined to bail out of the update and thus not create a new cache entry.

Immutability

Updates via setQueryData must be performed in an immutable way. DO NOT attempt to write directly to the cache by mutating oldData or data that you retrieved via getQueryData in place.

getQueryState is a synchronous function that can be used to get an existing query's state. If the query does not exist, undefined will be returned.

const state = queryClient.getQueryState(queryKey)
console.log(state.dataUpdatedAt)

Options

• queryKey: QueryKey: Query Keys

setQueriesData is a synchronous function that can be used to immediately update cached data of multiple queries by using filter function or partially matching the query key. Only queries that match the passed queryKey or queryFilter will be updated - no new cache entries will be created. Under the hood, setQueryData is called for each existing query.

queryClient.setQueriesData(filters, updater)

Options

• filters: QueryFilters: Query Filters
  • if a filter is passed, queryKeys matching the filter will be updated
• updater: TQueryFnData | (oldData: TQueryFnData | undefined) => TQueryFnData
  • the setQueryData updater function or new data, will be called for each matching queryKey

The invalidateQueries method can be used to invalidate and refetch single or multiple queries in the cache based on their query keys or any other functionally accessible property/state of the query. By default, all matching queries are immediately marked as invalid and active queries are refetched in the background.

• If you do not want active queries to refetch, and simply be marked as invalid, you can use the refetchType: 'none' option.
• If you want inactive queries to refetch as well, use the refetchType: 'all' option

await queryClient.invalidateQueries(
  {
    queryKey: ['posts'],
    exact,
    refetchType: 'active',
  },
  { throwOnError, cancelRefetch },
)

Options

• filters?: QueryFilters: Query Filters
  • queryKey?: QueryKey: Query Keys
  • refetchType?: 'active' | 'inactive' | 'all' | 'none'
    • Defaults to 'active'
    • When set to active, only queries that match the refetch predicate and are actively being rendered via useQuery and friends will be refetched in the background.
    • When set to inactive, only queries that match the refetch predicate and are NOT actively being rendered via useQuery and friends will be refetched in the background.
    • When set to all, all queries that match the refetch predicate will be refetched in the background.
    • When set to none, no queries will be refetched, and those that match the refetch predicate will be marked as invalid only.
• options?: InvalidateOptions:
  • throwOnError?: boolean
    • When set to true, this method will throw if any of the query refetch tasks fail.
  • cancelRefetch?: boolean
    • Defaults to true
      • Per default, a currently running request will be cancelled before a new request is made
    • When set to false, no refetch will be made if there is already a request running.

The refetchQueries method can be used to refetch queries based on certain conditions.

Examples:

// refetch all queries:
await queryClient.refetchQueries()

// refetch all stale queries:
await queryClient.refetchQueries({ stale: true })

// refetch all active queries partially matching a query key:
await queryClient.refetchQueries({ queryKey: ['posts'], type: 'active' })

// refetch all active queries exactly matching a query key:
await queryClient.refetchQueries({
  queryKey: ['posts', 1],
  type: 'active',
  exact: true,
})

Options

• filters?: QueryFilters: Query Filters
• options?: RefetchOptions:
  • throwOnError?: boolean
    • When set to true, this method will throw if any of the query refetch tasks fail.
  • cancelRefetch?: boolean
    • Defaults to true
      • Per default, a currently running request will be cancelled before a new request is made
    • When set to false, no refetch will be made if there is already a request running.

Returns

This function returns a promise that will resolve when all of the queries are done being refetched. By default, it will not throw an error if any of those queries refetches fail, but this can be configured by setting the throwOnError option to true

The cancelQueries method can be used to cancel outgoing queries based on their query keys or any other functionally accessible property/state of the query.

This is most useful when performing optimistic updates since you will likely need to cancel any outgoing query refetches so they don't clobber your optimistic update when they resolve.

await queryClient.cancelQueries({ queryKey: ['posts'], exact: true })

Options

• filters?: QueryFilters: Query Filters

Returns

This method does not return anything

The removeQueries method can be used to remove queries from the cache based on their query keys or any other functionally accessible property/state of the query.

queryClient.removeQueries({ queryKey, exact: true })

Options

• filters?: QueryFilters: Query Filters

Returns

This method does not return anything

The resetQueries method can be used to reset queries in the cache to their initial state based on their query keys or any other functionally accessible property/state of the query.

This will notify subscribers — unlike clear, which removes all subscribers — and reset the query to its pre-loaded state — unlike invalidateQueries. If a query has initialData, the query's data will be reset to that. If a query is active, it will be refetched.

queryClient.resetQueries({ queryKey, exact: true })

Options

• filters?: QueryFilters: Query Filters
• options?: ResetOptions:
  • throwOnError?: boolean
    • When set to true, this method will throw if any of the query refetch tasks fail.
  • cancelRefetch?: boolean
    • Defaults to true
      • Per default, a currently running request will be cancelled before a new request is made
    • When set to false, no refetch will be made if there is already a request running.

Returns

This method returns a promise that resolves when all active queries have been refetched.

This isFetching method returns an integer representing how many queries, if any, in the cache are currently fetching (including background-fetching, loading new pages, or loading more infinite query results)

if (queryClient.isFetching()) {
  console.log('At least one query is fetching!')
}

TanStack Query also exports a handy useIsFetching hook that will let you subscribe to this state in your components without creating a manual subscription to the query cache.

Options

• filters?: QueryFilters: Query Filters

Returns

This method returns the number of fetching queries.

This isMutating method returns an integer representing how many mutations, if any, in the cache are currently fetching.

if (queryClient.isMutating()) {
  console.log('At least one mutation is fetching!')
}

TanStack Query also exports a handy useIsMutating hook that will let you subscribe to this state in your components without creating a manual subscription to the mutation cache.

Options

• filters: MutationFilters: Mutation Filters

Returns

This method returns the number of fetching mutations.

The getDefaultOptions method returns the default options which have been set when creating the client or with setDefaultOptions.

const defaultOptions = queryClient.getDefaultOptions()

The setDefaultOptions method can be used to dynamically set the default options for this queryClient. Previously defined default options will be overwritten.

queryClient.setDefaultOptions({
  queries: {
    staleTime: Infinity,
  },
})

The getQueryDefaults method returns the default options which have been set for specific queries:

const defaultOptions = queryClient.getQueryDefaults(['posts'])

Note that if several query defaults match the given query key, the first matching one is returned. This could lead to unexpected behaviours. See setQueryDefaults.

setQueryDefaults can be used to set default options for specific queries:

queryClient.setQueryDefaults(['posts'], { queryFn: fetchPosts })

function Component() {
  const { data } = useQuery({ queryKey: ['posts'] })
}

Options

• queryKey: QueryKey: Query Keys
• options: QueryOptions

As stated in getQueryDefaults, the order of registration of query defaults does matter. Since the first matching defaults are returned by getQueryDefaults, the registration should be made in the following order: from the least generic key to the most generic one. This way, in case of specific key, the first matching one would be the expected one.

The getMutationDefaults method returns the default options which have been set for specific mutations:

const defaultOptions = queryClient.getMutationDefaults(['addPost'])

setMutationDefaults can be used to set default options for specific mutations:

queryClient.setMutationDefaults(['addPost'], { mutationFn: addPost })

function Component() {
  const { data } = useMutation({ mutationKey: ['addPost'] })
}

Options

• mutationKey: unknown[]
• options: MutationOptions

Similar to setQueryDefaults, the order of registration does matter here.

The getQueryCache method returns the query cache this client is connected to.

const queryCache = queryClient.getQueryCache()

The getMutationCache method returns the mutation cache this client is connected to.

const mutationCache = queryClient.getMutationCache()

The clear method clears all connected caches.

queryClient.clear()

Can be used to resume mutations that have been paused because there was no network connection.

queryClient.resumePausedMutations()