Hooks

Apollo Client react hooks API reference

Requires ≥ 3.0.0

The ApolloProvider component

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

JavaScript
1import { ApolloProvider } from '@apollo/client';

Props

OptionTypeDescription
clientApolloClient<TCache>An ApolloClient instance.

Example

JavaScript
1const client = new ApolloClient({
2  cache: new InMemoryCache(),
3  uri: "http://localhost:4000/graphql"
4});
5
6ReactDOM.render(
7  <ApolloProvider client={client}>
8    <MyRootComponent />
9  </ApolloProvider>,
10  document.getElementById('root'),
11);

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 argument. You can think of the ApolloConsumer component as similar to the Consumer component from the React Context API.

Example

JavaScript
1import { ApolloConsumer } from '@apollo/client';
2
3function WithApolloClient() {
4  return (
5    <ApolloConsumer>
6      {client => 'We have access to the client!' /* do stuff here */}
7    </ApolloConsumer>
8  );
9}

useQueryRequires ≥ 3.0.0

A hook for executing queries in an Apollo application.

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

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

JavaScript
1 import { gql, useQuery } from '@apollo/client';
2
3 const GET_GREETING = gql`
4   query GetGreeting($language: String!) {
5     greeting(language: $language) {
6       message
7     }
8   }
9 `;
10
11 function Hello() {
12   const { loading, error, data } = useQuery(GET_GREETING, {
13     variables: { language: 'english' },
14   });
15   if (loading) return <p>Loading ...</p>;
16   return <h1>Hello {data.greeting.message}!</h1>;
17 }

Signature

TypeScript
1useQuery<TData, TVariables>(
2  query: DocumentNode | TypedDocumentNode<TData, TVariables>,
3  options?: QueryHookOptions<NoInfer<TData>, NoInfer<TVariables>>
4): InteropQueryResult<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
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.

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, meaning that the query result includes error details but not partial results.

boolean

If true, the query is not executed.

The default value is false.

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.

(data: MaybeMasked<TData>) => void

⚠️ Deprecated

This option will be removed in the next major version of Apollo Client. For more context, please see the related issue on GitHub.

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

⚠️ Deprecated

This option will be removed in the next major version of Apollo Client. For more context, please see the related issue on GitHub.

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.

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.

boolean

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.

number

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

The default value is 0 (no polling).

() => boolean

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.

boolean

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<TVariables, TData>, currentFetchPolicy: WatchQueryFetchPolicy, context: NextFetchPolicyContext<TData, TVariables>) => WatchQueryFetchPolicy)

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

RefetchWritePolicy

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.

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.

Other
boolean

⚠️ Deprecated

Using canonizeResults can result in memory leaks so we generally do not recommend using this option. canonizeResults will be removed in Apollo Client 4.0.

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

boolean

⚠️ Deprecated

Setting this option is unnecessary in Apollo Client 3, thanks to a more consistent application of fetch policies. It will be removed in Apollo Client 4.0.

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

The default value is false.

Result

Query result object
InteropQueryResult<TData, TVariables>
Show/hide child attributes
Operation data
MaybeMasked<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.

MaybeMasked<TData>

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
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.

boolean

⚠️ Deprecated

called will be removed from the useQuery result in Apollo Client 4.0.

Recommended now

Please remove the use of the called property.

If true, the associated lazy query has been executed.

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

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

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

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

SubscribeToMoreFunction<TData, TVariables>

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.

(mapFn: UpdateQueryMapFn<TData, TVariables>) => 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.

ReadonlyArray<GraphQLFormattedError>

⚠️ Deprecated

This property will be removed in a future version of Apollo Client. Please use error.graphQLErrors instead.

useLazyQueryRequires ≥ 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

JavaScript
1 import { gql, useLazyQuery } from "@apollo/client";
2
3 const GET_GREETING = gql`
4   query GetGreeting($language: String!) {
5     greeting(language: $language) {
6       message
7     }
8   }
9 `;
10
11 function Hello() {
12   const [loadGreeting, { called, loading, data }] = useLazyQuery(
13     GET_GREETING,
14     { variables: { language: "english" } }
15   );
16   if (called && loading) return <p>Loading ...</p>
17   if (!called) {
18     return <button onClick={() => loadGreeting()}>Load greeting</button>
19   }
20   return <h1>Hello {data.greeting.message}!</h1>;
21 }

Signature

TypeScript
1useLazyQuery<TData, TVariables>(
2  query: DocumentNode | TypedDocumentNode<TData, TVariables>,
3  options?: LazyQueryHookOptions<NoInfer<TData>, NoInfer<TVariables>>
4): 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.

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, meaning that the query result includes error details but not partial results.

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.

(data: MaybeMasked<TData>) => void

⚠️ Deprecated

This option will be removed in Apollo Client 4.0. For more context, please see the related issue on GitHub.

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

⚠️ Deprecated

This option will be removed in Apollo Client 4.0. For more context, please see the related issue on GitHub.

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.

Networking options
boolean

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.

number

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

The default value is 0 (no polling).

() => boolean

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.

boolean

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

DefaultContext

⚠️ Deprecated

context will be removed in Apollo Client 4.0.

Recommended now

Please pass context to the returned execute function instead.

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

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

RefetchWritePolicy

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.

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.

WatchQueryFetchPolicy

⚠️ Deprecated

initialFetchPolicy will be removed in Apollo Client 4.0.

Recommended now

Please use fetchPolicy instead.

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).

Other
boolean

⚠️ Deprecated

Using canonizeResults can result in memory leaks so we generally do not recommend using this option. canonizeResults will be removed in Apollo Client 4.0.

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

boolean

⚠️ Deprecated

Setting this option is unnecessary in Apollo Client 3, thanks to a more consistent application of fetch policies. It will be removed in Apollo Client 4.0.

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

The default value is false.

Result

TypeScript
1[execute: LazyQueryExecFunction<TData, TVariables>, result: QueryResult<TData, TVariables>]
A tuple of two values:
Name / Type
Description
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.
result
QueryResult<TData, TVariables>
The result of the query. See the useQuery hook for more details.
Show/hide child attributes
Operation data
MaybeMasked<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.

MaybeMasked<TData>

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: Unmasked<TData>, options: { fetchMoreResult: Unmasked<TFetchData>; variables: TFetchVars; }) => Unmasked<TData>; }) => Promise<ApolloQueryResult<MaybeMasked<TFetchData>>>

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

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

SubscribeToMoreFunction<TData, TVariables>

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.

(mapFn: UpdateQueryMapFn<TData, TVariables>) => 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.

ReadonlyArray<GraphQLFormattedError>

⚠️ Deprecated

This property will be removed in a future version of Apollo Client. Please use error.graphQLErrors instead.

useMutationRequires ≥ 3.0.0

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

Example

JavaScript
1 import { gql, useMutation } from '@apollo/client';
2
3 const ADD_TODO = gql`
4   mutation AddTodo($type: String!) {
5     addTodo(type: $type) {
6       id
7       type
8     }
9   }
10 `;
11
12 function AddTodo() {
13   let input;
14   const [addTodo, { data }] = useMutation(ADD_TODO);
15
16   return (
17     <div>
18       <form
19         onSubmit={e => {
20           e.preventDefault();
21           addTodo({ variables: { type: input.value } });
22           input.value = '';
23         }}
24       >
25         <input
26           ref={node => {
27             input = node;
28           }}
29         />
30         <button type="submit">Add Todo</button>
31       </form>
32     </div>
33   );
34 }

Signature

TypeScript
1useMutation<TData, TVariables, TContext, TCache>(
2  mutation: DocumentNode | TypedDocumentNode<TData, TVariables>,
3  options?: MutationHookOptions<NoInfer<TData>, NoInfer<TVariables>, TContext, TCache>
4): MutationTuple<TData, TVariables, TContext, TCache>
(src/react/hooks/useMutation.ts)

Parameters

Name / Type
Description
mutation
DocumentNode | TypedDocumentNode<TData, TVariables>

A GraphQL mutation 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
boolean

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).

ErrorPolicy

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.

(data: MaybeMasked<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<Unmasked<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 operation name of the query to refetch

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.

boolean

⚠️ Deprecated

This option will be removed in Apollo Client 4.0. If you don't want to synchronize your component state with the mutation, please use useApolloClient to get your ApolloClient instance and call client.mutate directly.

If true:

  • The initial state update (setting loading to true) is skipped - The success state update (setting data and setting loading to false) is skipped - Error updates will still occur

The default value is false.

This option is useful when you want to execute a mutation but don't need to track its progress or result in the UI, potentially improving performance by reducing re-renders.

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.

TContext

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

boolean

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

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

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<TData, 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
boolean

To avoid retaining sensitive information from mutation root field arguments, 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<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

TypeScript
1[
2  mutate: (options?: MutationFunctionOptions<TData, TVariables>) => Promise<FetchResult<TData>>,
3  result: MutationResult<TData>
4]
A tuple of two values:
Name / Type
Description
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.
result
MutationResult<TData>
The result of the mutation.
Show/hide child attributes
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 operations or writing data to the cache.

MaybeMasked<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.

useSubscriptionRequires ≥ 3.0.0

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

Consider using onData instead of useEffect

If you want to react to incoming data, please use the onData option instead of useEffect. State updates you make inside a useEffect hook might cause additional rerenders, and useEffect is mostly meant for side effects of rendering, not as an event handler. State updates made in an event handler like onData might - depending on the React version - be batched and cause only a single rerender.

Consider the following component:

JavaScript
1export function Subscriptions() {
2  const { data, error, loading } = useSubscription(query);
3  const [accumulatedData, setAccumulatedData] = useState([]);
4
5  useEffect(() => {
6    setAccumulatedData((prev) => [...prev, data]);
7  }, [data]);
8
9  return (
10    <>
11      {loading && <p>Loading...</p>}
12      {JSON.stringify(accumulatedData, undefined, 2)}
13    </>
14  );
15}

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

JavaScript
1export function Subscriptions() {
2  const [accumulatedData, setAccumulatedData] = useState([]);
3  const { data, error, loading } = useSubscription(
4    query,
5    {
6      onData({ data }) {
7        setAccumulatedData((prev) => [...prev, data])
8      }
9    }
10  );
11
12  return (
13    <>
14      {loading && <p>Loading...</p>}
15      {JSON.stringify(accumulatedData, undefined, 2)}
16    </>
17  );
18}

⚠️ 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

JavaScript
1 const COMMENTS_SUBSCRIPTION = gql`
2   subscription OnCommentAdded($repoFullName: String!) {
3     commentAdded(repoFullName: $repoFullName) {
4       id
5       content
6     }
7   }
8 `;
9
10 function DontReadTheComments({ repoFullName }) {
11   const {
12     data: { commentAdded },
13     loading,
14   } = useSubscription(COMMENTS_SUBSCRIPTION, { variables: { repoFullName } });
15   return <h4>New comment: {!loading && commentAdded.content}</h4>;
16 }

Signature

TypeScript
1useSubscription<TData, TVariables>(
2  subscription: DocumentNode | TypedDocumentNode<TData, TVariables>,
3  options?: SubscriptionHookOptions<NoInfer<TData>, NoInfer<TVariables>>
4): {
5    restart: () => void;
6    loading: boolean;
7    data?: TData | undefined;
8    error?: ApolloError;
9    variables?: TVariables | undefined;
10}
(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
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 (Apollo Link).

ErrorPolicy

Specifies the ErrorPolicy to be used for this operation

Record<string, any>

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

FetchPolicy

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

boolean

If true, the hook will not cause the component to rerender. This is useful when you want to control the rendering of your component yourself with logic in the onData and onError callbacks.

Changing this to true when the hook already has data will reset the data to undefined.

onComplete(optional)Requires ≥ 3.7.0
() => void

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

onData(optional)Requires ≥ 3.7.0
(options: OnDataOptions<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.

onError(optional)Requires ≥ 3.7.0
(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<TData, TVariables>) => boolean)

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

boolean

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

TVariables

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

() => void

⚠️ 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<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
{
    restart: () => void;
    loading: boolean;
    data?: TData | undefined;
    error?: ApolloError;
    variables?: TVariables | undefined;
}

useApolloClientRequires ≥ 3.0.0

Example

JavaScript
1 import { useApolloClient } from '@apollo/client';
2
3 function SomeComponent() {
4   const client = useApolloClient();
5   // `client` is now set to the `ApolloClient` instance being used by the
6   // application (that was configured using something like `ApolloProvider`)
7 }

Signature

TypeScript
1useApolloClient(
2  override?: ApolloClient<object>
3): 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>

useReactiveVarRequires ≥ 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

JavaScript
1 import { makeVar, useReactiveVar } from "@apollo/client";
2 export const cartItemsVar = makeVar([]);
3
4 export function Cart() {
5   const cartItems = useReactiveVar(cartItemsVar);
6   // ...
7 }

Signature

TypeScript
1useReactiveVar<T>(
2  rv: ReactiveVar<T>
3): T
(src/react/hooks/useReactiveVar.ts)

Parameters

Name / Type
Description
rv
ReactiveVar<T>

A reactive variable.

Show/hide child attributes

Result

The current value of the reactive variable.
T

useFragmentRequires ≥ 3.8.0

useFragment represents a lightweight live binding into the Apollo Client Cache and enables Apollo Client to broadcast very specific fragment 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 querying 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

TypeScript
1function useFragment<
2  TData = any,
3  TVars = OperationVariables
4>({
5  from: string | StoreObject | Reference;
6  fragment: DocumentNode | TypedDocumentNode<TData, TVars>;
7  fragmentName?: string;
8  optimistic?: boolean;
9  variables?: TVars;
10  returnPartialData?: boolean;
11}): 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 entity 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.

useSuspenseQueryRequires ≥ 3.8.0

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

Example

JavaScript
1import { Suspense } from 'react';
2import { useSuspenseQuery } from '@apollo/client';
3
4const listQuery = gql`
5  query {
6    list {
7      id
8    }
9  }
10`;
11
12function App() {
13  return (
14    <Suspense fallback={<Spinner />}>
15      <List />
16    </Suspense>
17  );
18}
19
20function List() {
21  const { data } = useSuspenseQuery(listQuery);
22
23  return (
24    <ol>
25      {data.list.map(item => <Item key={item.id} id={item.id}/>)}
26    </ol>
27  );
28}
29

Signature

TypeScript
1function useSuspenseQuery<TData, TVariables>(
2  query: DocumentNode,
3  options?: SuspenseQueryHookOptions<TData, TVariables> | SkipToken,
4): 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
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.

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, meaning that the query result includes error details but not partial results.

boolean

⚠️ 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.

Recommended usage of skipToken:

TypeScript
1import { skipToken, useSuspenseQuery } from '@apollo/client';
2
3const { data } = useSuspenseQuery(query, id ? { variables: { id } } : skipToken);
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.

RefetchWritePolicy

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

The default value is "overwrite".

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.

Other
boolean

⚠️ Deprecated

Using canonizeResults can result in memory leaks so we generally do not recommend using this option. canonizeResults will be removed in Apollo Client 4.0.

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.

useBackgroundQueryRequires ≥ 3.8.0

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

Example

JavaScript
1import { Suspense } from 'react';
2import {
3  ApolloClient,
4  InMemoryCache,
5  useBackgroundQuery,
6  useReadQuery,
7} from '@apollo/client';
8
9const query = gql`
10  foo {
11    bar
12  }
13`;
14
15const client = new ApolloClient({
16  uri: "http://localhost:4000/graphql",
17  cache: new InMemoryCache()
18});
19
20function SuspenseFallback() {
21  return <div>Loading...</div>;
22}
23
24function Child({ queryRef }) {
25  const { data } = useReadQuery(queryRef);
26
27  return <div>{data.foo.bar}</div>;
28}
29
30function Parent() {
31  const [queryRef] = useBackgroundQuery(query);
32
33  return (
34    <Suspense fallback={<SuspenseFallback />}>
35      <Child queryRef={queryRef} />
36    </Suspense>
37  );
38}
39
40function App() {
41  return (
42    <ApolloProvider client={client}>
43      <Parent />
44    </ApolloProvider>
45  );
46}

Signature

TypeScript
1function useBackgroundQuery<TData, TVariables>(
2  query: DocumentNode | TypedDocumentNode<TData, TVariables>,
3  options: BackgroundQueryHookOptions<TData, TVariables> | SkipToken,
4): [
5  // Will return `undefined` here if no query has been executed yet and the query
6  // is currently skipped using `skipToken` or { skip: true }
7  QueryRef<TData> | undefined,
8  {
9    fetchMore: FetchMoreFunction<TData, TVariables>;
10    refetch: RefetchFunction<TData, TVariables>;
11  }
12]

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.

useReadQueryRequires ≥ 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

TypeScript
1function useReadQuery<TData>(
2  queryRef: QueryRef<TData>
3): {
4  data: TData;
5  networkStatus: NetworkStatus;
6  error: ApolloError | undefined;
7} {}

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.

useLoadableQueryRequires ≥ 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

JavaScript
1 import { gql, useLoadableQuery } from "@apollo/client";
2
3 const GET_GREETING = gql`
4   query GetGreeting($language: String!) {
5     greeting(language: $language) {
6       message
7     }
8   }
9 `;
10
11 function App() {
12   const [loadGreeting, queryRef] = useLoadableQuery(GET_GREETING);
13
14   return (
15     <>
16       <button onClick={() => loadGreeting({ language: "english" })}>
17         Load greeting
18       </button>
19       <Suspense fallback={<div>Loading...</div>}>
20         {queryRef && <Hello queryRef={queryRef} />}
21       </Suspense>
22     </>
23   );
24 }
25
26 function Hello({ queryRef }) {
27   const { data } = useReadQuery(queryRef);
28
29   return <div>{data.greeting.message}</div>;
30 }

Signature

TypeScript
1useLoadableQuery<TData, TVariables>(
2  query: DocumentNode | TypedDocumentNode<TData, TVariables>,
3  options?: LoadableQueryHookOptions
4): 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
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.

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, meaning that the query result includes error details but not partial results.

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
LoadableQueryHookFetchPolicy

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.

RefetchWritePolicy

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.

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.

Other
boolean

⚠️ Deprecated

Using canonizeResults can result in memory leaks so we generally do not recommend using this option. canonizeResults will be removed in Apollo Client 4.0.

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

TypeScript
1[
2  loadQuery: LoadQueryFunction<TVariables>,
3  queryRef: QueryRef<TData, TVariables> | null,
4  {
5    fetchMore: FetchMoreFunction<TData, TVariables>;
6    refetch: RefetchFunction<TData, TVariables>;
7    reset: ResetFunction;
8  }
9]
A tuple of three values:
Name / Type
Description
loadQuery
LoadQueryFunction<TVariables>
A function used to imperatively load a query. Calling this function will create or update the queryRef returned by useLoadableQuery, which should be passed to useReadQuery.
queryRef
QueryRef<TData, TVariables> | null
The queryRef used by useReadQuery to read the query result.
Show/hide child attributes
handlers
{ fetchMore: FetchMoreFunction<TData, TVariables>; refetch: RefetchFunction<TData, TVariables>; reset: ResetFunction; }
Additional handlers used for the query, such as refetch.

useQueryRefHandlersRequires ≥ 3.9.0

A React hook that returns a refetch and fetchMore function for a given queryRef.

This is useful to get access to handlers for a queryRef that was created by createQueryPreloader or when the handlers for a queryRef produced in a different component are inaccessible.

Example

TypeScript
1 const MyComponent({ queryRef }) {
2   const { refetch, fetchMore } = useQueryRefHandlers(queryRef);
3
4   // ...
5 }

Signature

TypeScript
1useQueryRefHandlers<TData, TVariables>(
2  queryRef: QueryRef<TData, TVariables>
3): UseQueryRefHandlersResult<TData, TVariables>
(src/react/hooks/useQueryRefHandlers.ts)

Parameters

Name / Type
Description
queryRef
QueryRef<TData, TVariables>

A QueryRef returned from useBackgroundQuery, useLoadableQuery, or createQueryPreloader.

Show/hide child attributes

Result

UseQueryRefHandlersResult<TData, TVariables>

skipTokenRequires ≥ 3.8.0

While not a hook by itself, skipToken is designed to be used with useSuspenseQuery and useBackgroundQuery. If a skipToken is passed into one of those hooks instead of the options object, that hook will not cause any requests or suspenseful behavior, while keeping the last data available.

JavaScript
Recommended usage of skipToken with useSuspenseQuery
1import { skipToken, useSuspenseQuery } from '@apollo/client';
2const { data } = useSuspenseQuery(
3  query,
4  id ? { variables: { id } } : skipToken
5);
JavaScript
Recommended usage of skipToken with useBackgroundQuery
1import { skipToken, useBackgroundQuery } from '@apollo/client';
2const [queryRef] = useBackgroundQuery(
3  query,
4  id ? { variables: { id } } : skipToken
5);
Note: Why do we recommend skipToken over { skip: true }?Imagine this very common scenario for skip: You want to skip your query if a certain variable is not set. You might be tempted to write something like this:
TypeScript
1const { data } = useSuspenseQuery(query, {
2  variables: { id },
3  skip: !id
4});
But in that case, TypeScript will complain:
Text
1Type 'number | undefined' is not assignable to type 'number'.
2      Type 'undefined' is not assignable to type 'number'.ts(2769)
To get around that, you have to tell TypeScript to ignore the fact that id could be undefined:
TypeScript
1const { data } = useSuspenseQuery(query, {
2  variables: { id: id! },
3  skip: !id
4});
Alternatively, you could also use some obscure default value:
TypeScript
1const { data } = useSuspenseQuery(query, {
2  variables: { id: id || 0 },
3  skip: !id
4});
What both of these solutions have in common: They hide a potential bug. If your skip logic becomes more complex in the future, you might accidentally introduce a bug that causes your query not to be skipped, even though id is still undefined - and TypeScript won't be able to warn you about it.So instead, we recommend using skipToken, as that will work without a lie to the compiler or an obscure default value:
TypeScript
1const { data } = useSuspenseQuery(
2  query,
3  id ? { variables: { id } } : skipToken
4);
In this case, it becomes apparent for TypeScript that there is a direct connection between skipping and the variables option - and it will work without unsafe workarounds.
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