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Since 3.0.0

Hooks

Apollo Client react hooks API reference


The ApolloProvider component

The ApolloProvider component leverages React's Context API to make a configured instance available throughout a React component tree. This component can be imported directly from the @apollo/client package.

import { ApolloProvider } from '@apollo/client';

Props

OptionTypeDescription
clientApolloClient<TCache>An ApolloClient instance.

Example

const client = new ApolloClient({
cache: new InMemoryCache(),
uri: "http://localhost:4000/graphql"
});
ReactDOM.render(
<ApolloProvider client={client}>
<MyRootComponent />
</ApolloProvider>,
document.getElementById('root'),
);

The ApolloConsumer component

One way to access the configured Apollo Client instance directly is to create an ApolloConsumer component and provide a render prop function as its child. The render prop function will be called with your ApolloClient instance as its only . You can think of the ApolloConsumer component as similar to the Consumer component from the React Context API.

Example

import { ApolloConsumer } from '@apollo/client';
function WithApolloClient() {
return (
<ApolloConsumer>
{client => 'We have access to the client!' /* do stuff here */}
</ApolloConsumer>
);
}

useQuery
Since 3.0.0

A hook for executing queries in an Apollo application.

To run a within a React component, call useQuery and pass it a query .

When your component renders, useQuery returns an object from Apollo Client that contains loading, error, and data properties you can use to render your UI.

Refer to the Queries section for a more in-depth overview of useQuery.

Example

import { gql, useQuery } from '@apollo/client';
const GET_GREETING = gql`
query GetGreeting($language: String!) {
greeting(language: $language) {
message
}
}
`;
function Hello() {
const { loading, error, data } = useQuery(GET_GREETING, {
variables: { language: 'english' },
});
if (loading) return <p>Loading ...</p>;
return <h1>Hello {data.greeting.message}!</h1>;
}

Signature

function useQuery<TData, TVariables>(
query: DocumentNode | TypedDocumentNode<TData, TVariables>,
options?: QueryHookOptions<NoInfer<TData>, NoInfer<TVariables>>
): QueryResult<TData, TVariables>

(src/react/hooks/useQuery.ts)

Parameters

Name / Type
Description

query

DocumentNode | TypedDocumentNode<TData, TVariables>

A GraphQL query document parsed into an AST by gql.

options (optional)

QueryHookOptions<NoInfer<TData>, NoInfer<TVariables>>

Options to control how the query is executed.

Show/hide child attributes
Operation options

client (optional)

ApolloClient<any>

The instance of ApolloClient to use to execute the query.

By default, the instance that's passed down via context is used, but you can provide a different instance here.

Specifies how the query handles a response that returns both GraphQL errors and partial results.

For details, see GraphQL error policies.

The default value is none, meaning that the query result includes error details but not partial results.

(data: NoInfer<TData>) => void

A callback function that's called when your query successfully completes with zero errors (or if errorPolicy is ignore and partial data is returned).

This function is passed the query's result data.

(error: ApolloError) => void

A callback function that's called when the query encounters one or more errors (unless errorPolicy is ignore).

This function is passed an ApolloError object that contains either a networkError object or a graphQLErrors array, depending on the error(s) that occurred.

If true, the query is not executed.

The default value is false.

NoInfer<TVariables>

An object containing all of the GraphQL your query requires to execute.

Each key in the object corresponds to a name, and that key's value corresponds to the variable value.

Networking options
DefaultContext

If you're using Apollo Link, this object is the initial value of the context object that's passed along your link chain.

If true, the in-progress query's associated component re-renders whenever the network status changes or a network error occurs.

The default value is false.

Specifies the interval (in milliseconds) at which the query polls for updated results.

The default value is 0 (no polling).

A callback function that's called whenever a refetch attempt occurs while polling. If the function returns true, the refetch is skipped and not reattempted until the next poll interval.

Pass false to skip executing the query during server-side rendering.

Caching options
WatchQueryFetchPolicy

Specifies how the query interacts with the Apollo Client cache during execution (for example, whether it checks the cache for results before sending a request to the server).

For details, see Setting a fetch policy.

The default value is cache-first.

WatchQueryFetchPolicy

Defaults to the initial value of options.fetchPolicy, but can be explicitly configured to specify the WatchFetchPolicy to revert back to whenever variables change (unless nextFetchPolicy intervenes).

WatchQueryFetchPolicy | ((this: WatchQueryOptions<NoInfer<TVariables>, NoInfer<TData>>, currentFetchPolicy: WatchQueryFetchPolicy, context: NextFetchPolicyContext<NoInfer<TData>, NoInfer<TVariables>>) => WatchQueryFetchPolicy)

Specifies the FetchPolicy to be used after this query has completed.

Specifies whether a NetworkStatus.refetch should merge incoming data with existing data, or overwrite the existing data. Overwriting is probably preferable, but merging is currently the default behavior, for backwards compatibility with Apollo Client 3.x.

If true, the query can return partial results from the cache if the cache doesn't contain results for all queried .

The default value is false.

Other

⚠️ Deprecated

Using canonizeResults can result in memory leaks so we generally do not recommend using this option anymore. A future version of Apollo Client will contain a similar feature without the risk of memory leaks.

Whether to canonize cache results before returning them. Canonization takes some extra time, but it speeds up future deep equality comparisons. Defaults to false.

⚠️ Deprecated

Setting this option is unnecessary in Apollo Client 3, thanks to a more consistent application of fetch policies. It might be removed in a future release.

If true, causes a query refetch if the query result is detected as partial.

The default value is false.

Result

Query result object
QueryResult<TData, TVariables>
Show/hide child attributes
Operation data
TData | undefined

An object containing the result of your GraphQL query after it completes.

This value might be undefined if a query results in one or more errors (depending on the query's errorPolicy).

ApolloError

If the query produces one or more errors, this object contains either an array of graphQLErrors or a single networkError. Otherwise, this value is undefined.

For more information, see Handling operation errors.

An object containing the result from the most recent previous execution of this query.

This value is undefined if this is the query's first execution.

TVariables | undefined

An object containing the variables that were provided for the query.

Network info
boolean

If true, the associated lazy query has been executed.

This field is only present on the result object returned by useLazyQuery.

ApolloClient<any>

The instance of Apollo Client that executed the query. Can be useful for manually executing followup queries or writing data to the cache.

boolean

If true, the query is still in flight and results have not yet been returned.

NetworkStatus

A number indicating the current network state of the query's associated request. See possible values.

Used in conjunction with the notifyOnNetworkStatusChange option.

Helper functions
<TFetchData = TData, TFetchVars extends OperationVariables = TVariables>(fetchMoreOptions: FetchMoreQueryOptions<TFetchVars, TFetchData> & { updateQuery?: (previousQueryResult: TData, options: { fetchMoreResult: TFetchData; variables: TFetchVars; }) => TData; }) => Promise<ApolloQueryResult<TFetchData>>

A function that helps you fetch the next set of results for a paginated list field.

(variables?: Partial<TVariables>) => Promise<ApolloQueryResult<TData>>

A function that enables you to re-execute the query, optionally passing in new variables.

To guarantee that the refetch performs a network request, its fetchPolicy is set to network-only (unless the original query's fetchPolicy is no-cache or cache-and-network, which also guarantee a network request).

See also Refetching.

(pollInterval: number) => void

A function that instructs the query to begin re-executing at a specified interval (in milliseconds).

() => void

A function that instructs the query to stop polling after a previous call to startPolling.

<TSubscriptionData = TData, TSubscriptionVariables extends OperationVariables = TVariables>(options: SubscribeToMoreOptions<TData, TSubscriptionVariables, TSubscriptionData>) => () => void

A function that enables you to execute a subscription, usually to subscribe to specific fields that were included in the query.

This function returns another function that you can call to terminate the .

<TVars extends OperationVariables = TVariables>(mapFn: (previousQueryResult: TData, options: Pick<WatchQueryOptions<TVars, TData>, "variables">) => TData) => void

A function that enables you to update the query's cached result without executing a followup GraphQL operation.

See using updateQuery and updateFragment for additional information.

Other
ObservableQuery<TData, TVariables>

A reference to the internal ObservableQuery used by the hook.

useLazyQuery
Since 3.0.0

A hook for imperatively executing queries in an Apollo application, e.g. in response to user interaction.

Refer to the Queries - Manual execution with useLazyQuery section for a more in-depth overview of useLazyQuery.

Example

import { gql, useLazyQuery } from "@apollo/client";
const GET_GREETING = gql`
query GetGreeting($language: String!) {
greeting(language: $language) {
message
}
}
`;
function Hello() {
const [loadGreeting, { called, loading, data }] = useLazyQuery(
GET_GREETING,
{ variables: { language: "english" } }
);
if (called && loading) return <p>Loading ...</p>
if (!called) {
return <button onClick={() => loadGreeting()}>Load greeting</button>
}
return <h1>Hello {data.greeting.message}!</h1>;
}

Signature

function useLazyQuery<TData, TVariables>(
query: DocumentNode | TypedDocumentNode<TData, TVariables>,
options?: LazyQueryHookOptions<NoInfer<TData>, NoInfer<TVariables>>
): LazyQueryResultTuple<TData, TVariables>

(src/react/hooks/useLazyQuery.ts)

Parameters

Name / Type
Description

query

DocumentNode | TypedDocumentNode<TData, TVariables>

A GraphQL query document parsed into an AST by gql.

options (optional)

LazyQueryHookOptions<NoInfer<TData>, NoInfer<TVariables>>

Default options to control how the query is executed.

Show/hide child attributes
Operation options
ApolloClient<any>

The instance of ApolloClient to use to execute the query.

By default, the instance that's passed down via context is used, but you can provide a different instance here.

Specifies how the query handles a response that returns both GraphQL errors and partial results.

For details, see GraphQL error policies.

The default value is none, meaning that the query result includes error details but not partial results.

(data: NoInfer<TData>) => void

A callback function that's called when your query successfully completes with zero errors (or if errorPolicy is ignore and partial data is returned).

This function is passed the query's result data.

(error: ApolloError) => void

A callback function that's called when the query encounters one or more errors (unless errorPolicy is ignore).

This function is passed an ApolloError object that contains either a networkError object or a graphQLErrors array, depending on the error(s) that occurred.

NoInfer<TVariables>

An object containing all of the GraphQL variables your query requires to execute.

Each key in the object corresponds to a variable name, and that key's value corresponds to the variable value.

Networking options
DefaultContext

If you're using Apollo Link, this object is the initial value of the context object that's passed along your link chain.

If true, the in-progress query's associated component re-renders whenever the network status changes or a network error occurs.

The default value is false.

Specifies the interval (in milliseconds) at which the query polls for updated results.

The default value is 0 (no polling).

A callback function that's called whenever a refetch attempt occurs while polling. If the function returns true, the refetch is skipped and not reattempted until the next poll interval.

Pass false to skip executing the query during server-side rendering.

Caching options
WatchQueryFetchPolicy

Specifies how the query interacts with the Apollo Client cache during execution (for example, whether it checks the cache for results before sending a request to the server).

For details, see Setting a fetch policy.

The default value is cache-first.

WatchQueryFetchPolicy

Defaults to the initial value of options.fetchPolicy, but can be explicitly configured to specify the WatchQueryFetchPolicy to revert back to whenever variables change (unless nextFetchPolicy intervenes).

WatchQueryFetchPolicy | ((this: WatchQueryOptions<NoInfer<TVariables>, NoInfer<TData>>, currentFetchPolicy: WatchQueryFetchPolicy, context: NextFetchPolicyContext<NoInfer<TData>, NoInfer<TVariables>>) => WatchQueryFetchPolicy)

Specifies the FetchPolicy to be used after this query has completed.

Specifies whether a NetworkStatus.refetch operation should merge incoming field data with existing data, or overwrite the existing data. Overwriting is probably preferable, but merging is currently the default behavior, for backwards compatibility with Apollo Client 3.x.

If true, the query can return partial results from the cache if the cache doesn't contain results for all queried fields.

The default value is false.

Other

⚠️ Deprecated

Using canonizeResults can result in memory leaks so we generally do not recommend using this option anymore. A future version of Apollo Client will contain a similar feature without the risk of memory leaks.

Whether to canonize cache results before returning them. Canonization takes some extra time, but it speeds up future deep equality comparisons. Defaults to false.

⚠️ Deprecated

Setting this option is unnecessary in Apollo Client 3, thanks to a more consistent application of fetch policies. It might be removed in a future release.

If true, causes a query refetch if the query result is detected as partial.

The default value is false.

Result

[execute: LazyQueryExecFunction<TData, TVariables>, result: QueryResult<TData, TVariables>]

A tuple of two values:

NameTypeDescription
execute(options?: LazyQueryHookOptions<TVariables>) => Promise<LazyQueryResult<TData, TVariables>>Function that can be triggered to execute the suspended query. After being called, `useLazyQuery` behaves just like `useQuery`. The `useLazyQuery` function returns a promise that fulfills with a query result when the query succeeds or fails.
resultQueryResult<TData, TVariables>The result of the query. See the `useQuery` hook for more details.
Show/hide child attributes
Operation data
TData | undefined

An object containing the result of your GraphQL query after it completes.

This value might be undefined if a query results in one or more errors (depending on the query's errorPolicy).

ApolloError

If the query produces one or more errors, this object contains either an array of graphQLErrors or a single networkError. Otherwise, this value is undefined.

For more information, see Handling operation errors.

An object containing the result from the most recent previous execution of this query.

This value is undefined if this is the query's first execution.

TVariables | undefined

An object containing the variables that were provided for the query.

Network info
boolean

If true, the associated lazy query has been executed.

This field is only present on the result object returned by useLazyQuery.

ApolloClient<any>

The instance of Apollo Client that executed the query. Can be useful for manually executing followup queries or writing data to the cache.

boolean

If true, the query is still in flight and results have not yet been returned.

NetworkStatus

A number indicating the current network state of the query's associated request. See possible values.

Used in conjunction with the notifyOnNetworkStatusChange option.

Helper functions
<TFetchData = TData, TFetchVars extends OperationVariables = TVariables>(fetchMoreOptions: FetchMoreQueryOptions<TFetchVars, TFetchData> & { updateQuery?: (previousQueryResult: TData, options: { fetchMoreResult: TFetchData; variables: TFetchVars; }) => TData; }) => Promise<ApolloQueryResult<TFetchData>>

A function that helps you fetch the next set of results for a paginated list field.

(variables?: Partial<TVariables>) => Promise<ApolloQueryResult<TData>>

A function that enables you to re-execute the query, optionally passing in new variables.

To guarantee that the refetch performs a network request, its fetchPolicy is set to network-only (unless the original query's fetchPolicy is no-cache or cache-and-network, which also guarantee a network request).

See also Refetching.

(pollInterval: number) => void

A function that instructs the query to begin re-executing at a specified interval (in milliseconds).

() => void

A function that instructs the query to stop polling after a previous call to startPolling.

<TSubscriptionData = TData, TSubscriptionVariables extends OperationVariables = TVariables>(options: SubscribeToMoreOptions<TData, TSubscriptionVariables, TSubscriptionData>) => () => void

A function that enables you to execute a subscription, usually to subscribe to specific fields that were included in the query.

This function returns another function that you can call to terminate the subscription.

<TVars extends OperationVariables = TVariables>(mapFn: (previousQueryResult: TData, options: Pick<WatchQueryOptions<TVars, TData>, "variables">) => TData) => void

A function that enables you to update the query's cached result without executing a followup GraphQL operation.

See using updateQuery and updateFragment for additional information.

Other
ObservableQuery<TData, TVariables>

A reference to the internal ObservableQuery used by the hook.

useMutation
Since 3.0.0

Refer to the Mutations section for a more in-depth overview of useMutation.

Example

import { gql, useMutation } from '@apollo/client';
const ADD_TODO = gql`
mutation AddTodo($type: String!) {
addTodo(type: $type) {
id
type
}
}
`;
function AddTodo() {
let input;
const [addTodo, { data }] = useMutation(ADD_TODO);
return (
<div>
<form
onSubmit={e => {
e.preventDefault();
addTodo({ variables: { type: input.value } });
input.value = '';
}}
>
<input
ref={node => {
input = node;
}}
/>
<button type="submit">Add Todo</button>
</form>
</div>
);
}

Signature

function useMutation<TData, TVariables, TContext, TCache>(
mutation: DocumentNode | TypedDocumentNode<TData, TVariables>,
options?: MutationHookOptions<NoInfer<TData>, NoInfer<TVariables>, TContext, TCache>
): MutationTuple<TData, TVariables, TContext, TCache>

(src/react/hooks/useMutation.ts)

Parameters

Name / Type
Description

mutation

DocumentNode | TypedDocumentNode<TData, TVariables>

A GraphQL document parsed into an AST by gql.

options (optional)

MutationHookOptions<NoInfer<TData>, NoInfer<TVariables>, TContext, TCache>

Options to control how the mutation is executed.

Show/hide child attributes
Operation options

If true, makes sure all queries included in refetchQueries are completed before the mutation is considered complete.

The default value is false (queries are refetched asynchronously).

Specifies how the mutation handles a response that returns both GraphQL errors and partial results.

For details, see GraphQL error policies.

The default value is none, meaning that the mutation result includes error details but not partial results.

If true, the mutation's data property is not updated with the mutation's result.

The default value is false.

(data: NoInfer<TData>, clientOptions?: BaseMutationOptions) => void

A callback function that's called when your mutation successfully completes with zero errors (or if errorPolicy is ignore and partial data is returned).

This function is passed the mutation's result data and any options passed to the mutation.

(error: ApolloError, clientOptions?: BaseMutationOptions) => void

A callback function that's called when the mutation encounters one or more errors (unless errorPolicy is ignore).

This function is passed an ApolloError object that contains either a networkError object or a graphQLErrors array, depending on the error(s) that occurred, as well as any options passed the mutation.

OnQueryUpdated<any>

Optional callback for intercepting queries whose cache data has been updated by the mutation, as well as any queries specified in the refetchQueries: [...] list passed to client.mutate.

Returning a Promise from onQueryUpdated will cause the final mutation Promise to await the returned Promise. Returning false causes the query to be ignored.

((result: FetchResult<NoInfer<TData>>) => InternalRefetchQueriesInclude) | InternalRefetchQueriesInclude

An array (or a function that returns an array) that specifies which queries you want to refetch after the mutation occurs.

Each array value can be either:

  • An object containing the query to execute, along with any variables

  • A string indicating the of the query to refetch

NoInfer<TVariables>

An object containing all of the GraphQL variables your mutation requires to execute.

Each key in the object corresponds to a variable name, and that key's value corresponds to the variable value.

Networking options
ApolloClient<object>

The instance of ApolloClient to use to execute the mutation.

By default, the instance that's passed down via context is used, but you can provide a different instance here.

If you're using Apollo Link, this object is the initial value of the context object that's passed along your link chain.

If true, the in-progress mutation's associated component re-renders whenever the network status changes or a network error occurs.

The default value is false.

Caching options
MutationFetchPolicy

Provide no-cache if the mutation's result should not be written to the Apollo Client cache.

The default value is network-only (which means the result is written to the cache).

Unlike queries, do not support fetch policies besides network-only and no-cache.

NoInfer<TData> | ((vars: NoInfer<TVariables>, { IGNORE }: { IGNORE: IgnoreModifier; }) => NoInfer<TData>)

By providing either an object or a callback function that, when invoked after a mutation, allows you to return optimistic data and optionally skip updates via the IGNORE sentinel object, Apollo Client caches this temporary (and potentially incorrect) response until the mutation completes, enabling more responsive UI updates.

For more information, see Optimistic mutation results.

MutationUpdaterFunction<NoInfer<TData>, NoInfer<TVariables>, TContext, TCache>

A function used to update the Apollo Client cache after the mutation completes.

For more information, see Updating the cache after a mutation.

Other

To avoid retaining sensitive information from mutation root field , Apollo Client v3.4+ automatically clears any ROOT_MUTATION fields from the cache after each mutation finishes. If you need this information to remain in the cache, you can prevent the removal by passing keepRootFields: true to the mutation. ROOT_MUTATION result data are also passed to the mutation update function, so we recommend obtaining the results that way, rather than using this option, if possible.

MutationQueryReducersMap<NoInfer<TData>>

A MutationQueryReducersMap, which is map from query names to mutation query reducers. Briefly, this map defines how to incorporate the results of the mutation into the results of queries that are currently being watched by your application.

Result

[
mutate: (options?: MutationFunctionOptions<TData, TVariables>) => Promise<FetchResult<TData>>,
result: MutationResult<TData>
]
A tuple of two values:
NameTypeDescription
mutate( options?: MutationFunctionOptions<TData, TVariables> ) => Promise<FetchResult<TData>>
A function to trigger the mutation from your UI. You can optionally pass this function any of the following options:
  • awaitRefetchQueries
  • context
  • fetchPolicy
  • onCompleted
  • onError
  • optimisticResponse
  • refetchQueries
  • onQueryUpdated
  • update
  • variables
  • client

Any option you pass here overrides any existing value for that option that you passed to useMutation.

The mutate function returns a promise that fulfills with your mutation result.

resultMutationResult<TData>The result of the mutation.
Show/hide child attributes
Other
boolean

If true, the mutation's mutate function has been called.

ApolloClient<object>

The instance of Apollo Client that executed the mutation.

Can be useful for manually executing followup or writing data to the cache.

TData | null

The data returned from your mutation. Can be undefined if ignoreResults is true.

ApolloError

If the mutation produces one or more errors, this object contains either an array of graphQLErrors or a single networkError. Otherwise, this value is undefined.

For more information, see Handling operation errors.

boolean

If true, the mutation is currently in flight.

() => void

A function that you can call to reset the mutation's result to its initial, uncalled state.

useSubscription
Since 3.0.0

Refer to the Subscriptions section for a more in-depth overview of useSubscription.

Subscriptions and React 18 Automatic Batching

With React 18's automatic batching, multiple state updates may be grouped into a single re-render for better performance.

If your subscription API sends multiple messages at the same time or in very fast succession (within fractions of a millisecond), it is likely that only the last message received in that narrow time frame will result in a re-render.

Consider the following component:

export function Subscriptions() {
const { data, error, loading } = useSubscription(query);
const [accumulatedData, setAccumulatedData] = useState([]);
useEffect(() => {
setAccumulatedData((prev) => [...prev, data]);
}, [data]);
return (
<>
{loading && <p>Loading...</p>}
{JSON.stringify(accumulatedData, undefined, 2)}
</>
);
}

If your subscription back-end emits two messages with the same timestamp, only the last message received by Apollo Client will be rendered. This is because React 18 will batch these two state updates into a single re-render.

Since the component above is using useEffect to push data into a piece of local state on each Subscriptions re-render, the first message will never be added to the accumulatedData array since its render was skipped.

Instead of using useEffect here, we can re-write this component to use the onData callback function accepted in useSubscription's options object:

export function Subscriptions() {
const [accumulatedData, setAccumulatedData] = useState([]);
const { data, error, loading } = useSubscription(
query,
{
onData({ data }) {
setAccumulatedData((prev) => [...prev, data])
}
}
);
return (
<>
{loading && <p>Loading...</p>}
{JSON.stringify(accumulatedData, undefined, 2)}
</>
);
}

⚠️ Note: The useSubscription option onData is available in Apollo Client >= 3.7. In previous versions, the equivalent option is named onSubscriptionData.

Now, the first message will be added to the accumulatedData array since onData is called before the component re-renders. React 18 automatic batching is still in effect and results in a single re-render, but with onData we can guarantee each message received after the component mounts is added to accumulatedData.

Example

const COMMENTS_SUBSCRIPTION = gql`
subscription OnCommentAdded($repoFullName: String!) {
commentAdded(repoFullName: $repoFullName) {
id
content
}
}
`;
function DontReadTheComments({ repoFullName }) {
const {
data: { commentAdded },
loading,
} = useSubscription(COMMENTS_SUBSCRIPTION, { variables: { repoFullName } });
return <h4>New comment: {!loading && commentAdded.content}</h4>;
}

Signature

function useSubscription<TData, TVariables>(
subscription: DocumentNode | TypedDocumentNode<TData, TVariables>,
options?: SubscriptionHookOptions<NoInfer<TData>, NoInfer<TVariables>>
): SubscriptionResult<TData, TVariables>

(src/react/hooks/useSubscription.ts)

Parameters

Name / Type
Description

subscription

DocumentNode | TypedDocumentNode<TData, TVariables>

A GraphQL subscription document parsed into an AST by gql.

options (optional)

SubscriptionHookOptions<NoInfer<TData>, NoInfer<TVariables>>

Options to control how the subscription is executed.

Show/hide child attributes
Other
ApolloClient<object>

An ApolloClient instance. By default useSubscription / Subscription uses the client passed down via context, but a different client can be passed in.

DefaultContext

Shared context between your component and your network interface ().

How you want your component to interact with the Apollo cache. For details, see Setting a fetch policy.

() => void

Allows the registration of a callback function that will be triggered each time the useSubscription Hook / Subscription component completes the subscription.

(options: OnDataOptions<NoInfer<TData>>) => any

Allows the registration of a callback function that will be triggered each time the useSubscription Hook / Subscription component receives data. The callback options object param consists of the current Apollo Client instance in client, and the received subscription data in data.

(error: ApolloError) => void

Allows the registration of a callback function that will be triggered each time the useSubscription Hook / Subscription component receives an error.

boolean | ((options: BaseSubscriptionOptions<NoInfer<TData>, NoInfer<TVariables>>) => boolean)

Determines if your subscription should be unsubscribed and subscribed again when an input to the hook (such as subscription or variables) changes.

Determines if the current subscription should be skipped. Useful if, for example, variables depend on previous queries and are not ready yet.

NoInfer<TVariables>

An object containing all of the variables your subscription needs to execute

⚠️ Deprecated

Use onComplete instead

Allows the registration of a callback function that will be triggered when the useSubscription Hook / Subscription component completes the subscription.

(options: OnSubscriptionDataOptions<NoInfer<TData>>) => any

⚠️ Deprecated

Use onData instead

Allows the registration of a callback function that will be triggered each time the useSubscription Hook / Subscription component receives data. The callback options object param consists of the current Apollo Client instance in client, and the received subscription data in subscriptionData.

Result

Query result object
SubscriptionResult<TData, TVariables>
Show/hide child attributes
Other

An object containing the result of your GraphQL subscription. Defaults to an empty object.

ApolloError

A runtime error with graphQLErrors and networkError properties

boolean

A boolean that indicates whether any initial data has been returned

useApolloClient
Since 3.0.0

Example

import { useApolloClient } from '@apollo/client';
function SomeComponent() {
const client = useApolloClient();
// `client` is now set to the `ApolloClient` instance being used by the
// application (that was configured using something like `ApolloProvider`)
}

Signature

function useApolloClient(
override?: ApolloClient<object>
): ApolloClient<object>

(src/react/hooks/useApolloClient.ts)

Parameters

Name / Type
Description

override (optional)

ApolloClient<object>

Result

The `ApolloClient` instance being used by the application.
ApolloClient<object>

useReactiveVar
Since 3.2.0

Reads the value of a reactive variable and re-renders the containing component whenever that variable's value changes. This enables a reactive variable to trigger changes without relying on the useQuery hook.

Example

import { makeVar, useReactiveVar } from "@apollo/client";
export const cartItemsVar = makeVar([]);
export function Cart() {
const cartItems = useReactiveVar(cartItemsVar);
// ...
}

Signature

function useReactiveVar<T>(
rv: ReactiveVar<T>
): T

(src/react/hooks/useReactiveVar.ts)

Parameters

Name / Type
Description

rv

ReactiveVar<T>

A reactive variable.

Show/hide child attributes
Other
( cache: ApolloCache<any> ) => this
( cache: ApolloCache<any> ) => boolean
( listener: ReactiveListener<T> ) => () => void

Result

The current value of the reactive variable.
T

useFragment
Since 3.8.0

useFragment represents a lightweight live binding into the Apollo Client Cache and enables Apollo Client to broadcast very specific results to individual components. This hook returns an always-up-to-date view of whatever data the cache currently contains for a given fragment. useFragment never triggers network requests of its own.

Note that the useQuery hook remains the primary hook responsible for and populating data in the cache (see the API reference). As a result, the component reading the fragment data via useFragment is still subscribed to all changes in the query data, but receives updates only when that fragment's specific data change.

Note: this hook was introduced in 3.7.0 as experimental but stabilized in 3.8.0. In 3.7.x and 3.8.0-alpha.x releases, this hook is exported as useFragment_experimental. Starting with 3.8.0-beta.0 and greater the _experimental suffix was removed in its named export.

Example

To view a useFragment example, see the Fragments page.

Function Signature

function useFragment<
TData = any,
TVars = OperationVariables
>({
from: string | StoreObject | Reference;
fragment: DocumentNode | TypedDocumentNode<TData, TVars>;
fragmentName?: string;
optimistic?: boolean;
variables?: TVars;
returnPartialData?: boolean;
}): UseFragmentResult<TData> {}

Params

options

Name /
Type
Description

Operation options

from

string | StoreObject | Reference

Required. An object containing a __typename and primary key fields (such as id) identifying the object from which the fragment will be retrieved, or a { __ref: "..." } reference, or a string ID (uncommon).

fragment

DocumentNode

Required. A GraphQL fragment document parsed into an AST with the gql template literal.

fragmentName

string

The name of the fragment defined in the fragment document to use in the call.

Required if the fragment document includes more than one fragment, optional otherwise.

optimistic

boolean

If true, readFragment returns optimistic results.

The default value is true.

variables

{ [key: string]: any }

An object containing all of the GraphQL variables your fragment requires.

Each key in the object corresponds to a variable name, and that key's value corresponds to the variable value.

canonizeResults

boolean

⚠️ Deprecated: Using canonizeResults can result in memory leaks so we generally do not recommend using this option anymore. A future version of Apollo Client will contain a similar feature without the risk of memory leaks.

If true, result objects read from the cache will be canonized, which means deeply-equal objects will also be === (literally the same object), allowing much more efficient comparison of past/present results.

The default value is false.

Result

Name /
Type
Description

Operation result

data

TData

An object containing the data for a given GraphQL fragment.

This value might be undefined if a query results in one or more errors (depending on the query's errorPolicy).

complete

boolean

A boolean indicating whether the data returned for the fragment is complete. When false, the missing field should explain which fields were responsible for the incompleteness.

missing

MissingTree

A tree of all MissingFieldError messages reported during fragment reading, where the branches of the tree indicate the paths of the errors within the query result.

useSuspenseQuery
Since 3.8.0

For a detailed explanation of useSuspenseQuery, see the fetching with Suspense reference.

Example

import { Suspense } from 'react';
import { useSuspenseQuery } from '@apollo/client';
const listQuery = gql`
query {
list {
id
}
}
`;
function App() {
return (
<Suspense fallback={<Spinner />}>
<List />
</Suspense>
);
}
function List() {
const { data } = useSuspenseQuery(listQuery);
return (
<ol>
{data.list.map(item => <Item key={item.id} id={item.id}/>)}
</ol>
);
}

Signature

function useSuspenseQuery<TData, TVariables>(
query: DocumentNode,
options?: SuspenseQueryHookOptions<TData, TVariables> | SkipToken,
): UseSuspenseQueryResult<TData, TVariables>

Params

query

ParamTypeDescription
query(Typed)DocumentNodeA GraphQL query document parsed into an AST by gql.

options

Instead of passing a SuspenseQueryHookOptions object into the hook, you can also pass a skipToken to prevent the useSuspenseQuery hook from executing the query or suspending.

Properties

Name / Type
Description

An object containing all of the GraphQL variables your query requires to execute.

Each key in the object corresponds to a variable name, and that key's value corresponds to the variable value.

Specifies how the query handles a response that returns both GraphQL errors and partial results.

For details, see GraphQL error policies.

The default value is none, meaning that the query result includes error details but not partial results.

⚠️ Deprecated

We recommend using skipToken in place of the skip option as it is more type-safe.

This option is deprecated and only supported to ease the migration from useQuery. It will be removed in a future release.

If true, the query is not executed. The default value is false.

Operation options
ApolloClient<any>

The instance of ApolloClient to use to execute the query.

By default, the instance that's passed down via context is used, but you can provide a different instance here.

string | number | any[]

A unique identifier for the query. Each item in the array must be a stable identifier to prevent infinite fetches.

This is useful when using the same query and variables combination in more than one component, otherwise the components may clobber each other. This can also be used to force the query to re-evaluate fresh.

Networking options
DefaultContext

If you're using Apollo Link, this object is the initial value of the context object that's passed along your link chain.

Caching options
SuspenseQueryHookFetchPolicy

Specifies how the query interacts with the Apollo Client cache during execution (for example, whether it checks the cache for results before sending a request to the server).

For details, see Setting a fetch policy.

The default value is cache-first.

Watched queries must opt into overwriting existing data on refetch, by passing refetchWritePolicy: "overwrite" in their WatchQueryOptions.

The default value is "overwrite".

If true, the query can return partial results from the cache if the cache doesn't contain results for all queried fields.

The default value is false.

Other

⚠️ Deprecated

Using canonizeResults can result in memory leaks so we generally do not recommend using this option anymore. A future version of Apollo Client will contain a similar feature without the risk of memory leaks.

Whether to canonize cache results before returning them. Canonization takes some extra time, but it speeds up future deep equality comparisons. Defaults to false.

Result

Name /
Type
Description

Operation result

data

TData

An object containing the result of your GraphQL query after it completes.

This value might be undefined if a query results in one or more errors (depending on the query's errorPolicy).

error

ApolloError

If the query produces one or more errors, this object contains either an array of graphQLErrors or a single networkError. Otherwise, this value is undefined.

This property can be ignored when using the default errorPolicy or an errorPolicy of none. The hook will throw the error instead of setting this property.

networkStatus

NetworkStatus

A number indicating the current network state of the query's associated request. See possible values.

Client

client

ApolloClient

The instance of Apollo Client that executed the query.

Can be useful for manually executing followup queries or writing data to the cache.

Helper functions

refetch

(variables?: Partial<TVariables>) => Promise<ApolloQueryResult>

A function that enables you to re-execute the query, optionally passing in new variables.

To guarantee that the refetch performs a network request, its fetchPolicy is set to network-only (unless the original query's fetchPolicy is no-cache or cache-and-network, which also guarantee a network request).

Calling this function will cause the component to re-suspend, unless the call site is wrapped in startTransition.

fetchMore

({ query?: DocumentNode, variables?: TVariables, updateQuery: Function}) => Promise<ApolloQueryResult>

A function that helps you fetch the next set of results for a paginated list field.

Calling this function will cause the component to re-suspend, unless the call site is wrapped in startTransition.

subscribeToMore

(options: { document: DocumentNode, variables?: TVariables, updateQuery?: Function, onError?: Function}) => () => void

A function that enables you to execute a subscription, usually to subscribe to specific fields that were included in the query.

This function returns another function that you can call to terminate the subscription.

For a detailed explanation of useBackgroundQuery, see the fetching with Suspense reference.

Example

import { Suspense } from 'react';
import {
ApolloClient,
InMemoryCache,
useBackgroundQuery,
useReadQuery,
} from '@apollo/client';
const query = gql`
foo {
bar
}
`;
const client = new ApolloClient({
uri: "http://localhost:4000/graphql",
cache: new InMemoryCache()
});
function SuspenseFallback() {
return <div>Loading...</div>;
}
function Child({ queryRef }) {
const { data } = useReadQuery(queryRef);
return <div>{data.foo.bar}</div>;
}
function Parent() {
const [queryRef] = useBackgroundQuery(query);
return (
<Suspense fallback={<SuspenseFallback />}>
<Child queryRef={queryRef} />
</Suspense>
);
}
function App() {
return (
<ApolloProvider client={client}>
<Parent />
</ApolloProvider>
);
}

Signature

function useBackgroundQuery<TData, TVariables>(
query: DocumentNode | TypedDocumentNode<TData, TVariables>,
options: BackgroundQueryHookOptions<TData, TVariables> | SkipToken,
): [
// Will return `undefined` here if no query has been executed yet and the query
// is currently skipped using `skipToken` or { skip: true }
QueryRef<TData> | undefined,
{
fetchMore: FetchMoreFunction<TData, TVariables>;
refetch: RefetchFunction<TData, TVariables>;
}
]

Params

query

ParamTypeDescription
query(Typed)DocumentNodeA GraphQL query document parsed into an AST by gql.

options

Instead of passing a BackgroundQueryHookOptions object into the hook, you can also pass a skipToken to prevent the useBackgroundQuery hook from executing the query.

If no query has been executed yet and you skip the query, the hook will return undefined instead of a queryRef.

Name /
Type
Description

Operation options

variables

{ [key: string]: any }

An object containing all of the GraphQL variables your query requires to execute.

Each key in the object corresponds to a variable name, and that key's value corresponds to the variable value.

errorPolicy

ErrorPolicy

Specifies how the query handles a response that returns both GraphQL errors and partial results.

For details, see GraphQL error policies.

The default value is none, which causes the useReadQuery hook to throw the error.

Networking options

context

Record<string, any>

If you're using Apollo Link, this object is the initial value of the context object that's passed along your link chain.

canonizeResults

Boolean

⚠️ Deprecated: Using canonizeResults can result in memory leaks so we generally do not recommend using this option anymore. A future version of Apollo Client will contain a similar feature without the risk of memory leaks.

If true, result objects read from the cache will be canonized, which means deeply-equal objects will also be === (literally the same object), allowing much more efficient comparison of past/present results.

The default value is false.

client

ApolloClient

The instance of ApolloClient to use to execute the query.

By default, the instance that's passed down via context is used, but you can provide a different instance here.

Caching options

fetchPolicy

SuspenseQueryHookFetchPolicy

Specifies how the query interacts with the Apollo Client cache during execution (for example, whether it checks the cache for results before sending a request to the server).

For details, see Setting a fetch policy. This hook only supports the cache-first, network-only, no-cache, and cache-and-network fetch policies.

The default value is cache-first.

returnPartialData

boolean

If true, the query can return partial results from the cache if the cache doesn't contain results for all queried fields.

The default value is false.

refetchWritePolicy

"merge" | "overwrite"

Watched queries must opt into overwriting existing data on refetch, by passing refetchWritePolicy: "overwrite" in their WatchQueryOptions.

The default value is "overwrite".

skip (deprecated)

boolean

If true, the query is not executed. The default value is false.

This option is deprecated and only supported to ease the migration from useQuery. It will be removed in a future release. Please use skipToken instead of the skip option as it is more type-safe.

Result

Name /
Type
Description

Query reference

queryRef

QueryRef<TData>

In order to link a query initiated by a specific useBackgroundQuery call to the place its data is consumed—which can be uniquely identified not only by the query and variables passed, but also the optional queryKey supplied by the user—the hook returns a queryRef that can later be read by useReadQuery.

Helper functions

refetch

(variables?: Partial<TVariables>) => Promise<ApolloQueryResult>

A function that enables you to re-execute the query, optionally passing in new variables.

To guarantee that the refetch performs a network request, its fetchPolicy is set to network-only (unless the original query's fetchPolicy is no-cache or cache-and-network, which also guarantee a network request).

Calling this function will cause the component to re-suspend, unless the call site is wrapped in startTransition.

fetchMore

({ query?: DocumentNode, variables?: TVariables, updateQuery: Function}) => Promise<ApolloQueryResult>

A function that helps you fetch the next set of results for a paginated list field.

Calling this function will cause the component to re-suspend, unless the call site is wrapped in startTransition.

useReadQuery
Since 3.8.0

For a detailed explanation of useReadQuery, see the fetching with Suspense reference.

Example

See the example in the useBackgroundQuery section above.

Signature

function useReadQuery<TData>(
queryRef: QueryRef<TData>
): {
data: TData;
networkStatus: NetworkStatus;
error: ApolloError | undefined;
} {}

Params

queryRef

ParamTypeDescription
queryRefQueryRefThe queryRef that was generated via useBackgroundQuery.

Result

Name /
Type
Description

Operation result

data

TData

An object containing the result of your GraphQL query after it completes.

This value might be undefined if a query results in one or more errors (depending on the query's errorPolicy).

error

ApolloError

If the query produces one or more errors, this object contains either an array of graphQLErrors or a single networkError. Otherwise, this value is undefined.

This property can be ignored when using the default errorPolicy or an errorPolicy of none. The hook will throw the error instead of setting this property.

networkStatus

NetworkStatus

A number indicating the current network state of the query's associated request. See possible values.

useLoadableQuery
Since 3.9.0

A hook for imperatively loading a query, such as responding to a user interaction.

Refer to the Suspense - Fetching in response to user interaction section for a more in-depth overview of useLoadableQuery.

Example

import { gql, useLoadableQuery } from "@apollo/client";
const GET_GREETING = gql`
query GetGreeting($language: String!) {
greeting(language: $language) {
message
}
}
`;
function App() {
const [loadGreeting, queryRef] = useLoadableQuery(GET_GREETING);
return (
<>
<button onClick={() => loadGreeting({ language: "english" })}>
Load greeting
</button>
<Suspense fallback={<div>Loading...</div>}>
{queryRef && <Hello queryRef={queryRef} />}
</Suspense>
</>
);
}
function Hello({ queryRef }) {
const { data } = useReadQuery(queryRef);
return <div>{data.greeting.message}</div>;
}

Signature

function useLoadableQuery<TData, TVariables>(
query: DocumentNode | TypedDocumentNode<TData, TVariables>,
options?: LoadableQueryHookOptions
): UseLoadableQueryResult<TData, TVariables>

(src/react/hooks/useLoadableQuery.ts)

Parameters

Name / Type
Description

query

DocumentNode | TypedDocumentNode<TData, TVariables>

A GraphQL query document parsed into an AST by gql.

options (optional)

LoadableQueryHookOptions

Options to control how the query is executed.

Show/hide child attributes
Operation options