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ApolloClient

ApolloClient API reference


The ApolloClient class encapsulates Apollo's core client-side API. It backs all available view-layer integrations (React, iOS, and so on).

The ApolloClient constructor

constructor(options)

(src/ApolloClient.ts, line 75)

Constructs an instance of ApolloClient.

The constructor for ApolloClient accepts an ApolloClientOptions object that supports the required and optional fields listed below. These fields make it easy to customize how Apollo works based on your application's needs.

Example constructor call

import { ApolloClient } from 'apollo-client';
import { InMemoryCache } from 'apollo-cache-inmemory';
import { HttpLink } from 'apollo-link-http';

// Instantiate required constructor fields
const cache = new InMemoryCache();
const link = new HttpLink({
  uri: 'http://localhost:4000/',
});

const client = new ApolloClient({
  // Provide required constructor fields
  cache: cache,
  link: link,

  // Provide some optional constructor fields
  name: 'react-web-client',
  version: '1.3',
  queryDeduplication: false,
  defaultOptions: {
    watchQuery: {
      fetchPolicy: 'cache-and-network',
    },
  },
});

Required fields

NameDescription
uriA URI pointing to the backend GraphQL endpoint that Apollo Client will communicate with. Note: One of uri or link is required; if both are specified, link will take precedence.
linkYou can provide an Apollo Link instance to serve as Apollo Client's network layer. For more information, see the advanced HTTP networking section. Note: One of uri or link is required; if both are specified, link will take precedence.
cacheApollo Client uses an Apollo Cache instance to handle its caching strategy. The recommended cache is apollo-cache-inmemory, which exports an { InMemoryCache }. For more information, see Configuring the cache.

Optional fields

NameDescription
nameA custom name (e.g., iOS) that identifies this particular client among your set of clients. Apollo Server uses this property as part of its Client Awareness feature.
versionA custom version that identifies the current version of this particular client (e.g., 1.2). Apollo Server uses this property as part of its Client Awareness feature.

Note that this version string is not the version of Apollo Client that you are using, but rather any version string that helps you differentiate between versions of your client.
ssrModeWhen using Apollo Client for server-side rendering, set this to true so that React Apollo's getDataFromTree function can work effectively.
ssrForceFetchDelayProvide this to specify a time interval (in milliseconds) before Apollo Client force-fetches queries after a server-side render. This value is 0 by default.
connectToDevToolsSet this to true to allow the Apollo Client Devtools Chrome extension to connect to your application's Apollo Client in production. (This connection is allowed automatically in dev mode.)
queryDeduplicationSet this to false to force all created queries to be sent to the server, even if a query with completely identical parameters (query, variables, operationName) is already in flight.
defaultOptionsProvide this object to set application-wide default values for options you can provide to the watchQuery, query, and mutate functions. See below for an example object.

Example defaultOptions object

const defaultOptions = {
  watchQuery: {
    fetchPolicy: 'cache-and-network',
    errorPolicy: 'ignore',
  },
  query: {
    fetchPolicy: 'network-only',
    errorPolicy: 'all',
  },
  mutate: {
    errorPolicy: 'all',
  },
};

You can override any default option you specify in this object by providing a different value for the same option in individual function calls.

Note: The <Query /> React component uses Apollo Client's watchQuery function. To set defaultOptions when using the <Query /> component, make sure to set them under the defaultOptions.watchQuery property.

ApolloClient functions

This watches the cache store of the query according to the options specified and returns an ObservableQuery. We can subscribe to this ObservableQuery and receive updated results through a GraphQL observer when the cache store changes.

Options
context any

Context to be passed to link execution chain

errorPolicy "none" | "ignore" | "all"

Specifies the ErrorPolicy to be used for this query

fetchPolicy "cache-first" | "network-only" | "cache-only" | "no-cache" | "standby" | "cache-and-network"

Specifies the FetchPolicy to be used for this query

notifyOnNetworkStatusChange any

Whether or not updates to the network status should trigger next on the observer of this query

partialRefetch any

If true, perform a query refetch if the query result is marked as being partial, and the returned data is reset to an empty Object by the Apollo Client QueryManager (due to a cache miss).

pollInterval any

The time interval (in milliseconds) on which this query should be refetched from the server.

query DocumentNode

A GraphQL document that consists of a single query to be sent down to the server.

returnPartialData any

Allow returning incomplete data from the cache when a larger query cannot be fully satisfied by the cache, instead of returning nothing.

variables TVariables

A map going from variable name to variable value, where the variables are used within the GraphQL query.

This resolves a single query according to the options specified and returns a Promise which is either resolved with the resulting data or rejected with an error.

Options
context any

Context to be passed to link execution chain

errorPolicy "none" | "ignore" | "all"

Specifies the ErrorPolicy to be used for this query

fetchPolicy "cache-first" | "network-only" | "cache-only" | "no-cache" | "standby"

Specifies the FetchPolicy to be used for this query

query DocumentNode

A GraphQL document that consists of a single query to be sent down to the server.

variables TVariables

A map going from variable name to variable value, where the variables are used within the GraphQL query.

This resolves a single mutation according to the options specified and returns a Promise which is either resolved with the resulting data or rejected with an error.

Options
awaitRefetchQueries any

By default, refetchQueries does not wait for the refetched queries to be completed, before resolving the mutation Promise. This ensures that query refetching does not hold up mutation response handling (query refetching is handled asynchronously). Set awaitRefetchQueries to true if you would like to wait for the refetched queries to complete, before the mutation can be marked as resolved.

context any

The context to be passed to the link execution chain. This context will only be used with the mutation. It will not be used with refetchQueries. Refetched queries use the context they were initialized with (since the intitial context is stored as part of the ObservableQuery instance). If a specific context is needed when refetching queries, make sure it is configured (via the query context option) when the query is first initialized/run.

errorPolicy "none" | "ignore" | "all"

Specifies the ErrorPolicy to be used for this operation

fetchPolicy Extract<"cache-first" | "network-only" | "cache-only" | "no-cache" | "standby", "no-cache">

Specifies the FetchPolicy to be used for this query. Mutations only support a 'no-cache' fetchPolicy. If you don't want to disable the cache, remove your fetchPolicy setting to proceed with the default mutation behavior.

mutation DocumentNode

A GraphQL document, often created with gql from the graphql-tag package, that contains a single mutation inside of it.

optimisticResponse any

An object that represents the result of this mutation that will be optimistically stored before the server has actually returned a result. This is most often used for optimistic UI, where we want to be able to see the result of a mutation immediately, and update the UI later if any errors appear.

refetchQueries any

A list of query names which will be refetched once this mutation has returned. This is often used if you have a set of queries which may be affected by a mutation and will have to update. Rather than writing a mutation query reducer (i.e. updateQueries) for this, you can simply refetch the queries that will be affected and achieve a consistent store once these queries return.

update (ApolloCache<>, FetchResult<>) => any<>

This function will be called twice over the lifecycle of a mutation. Once at the very beginning if an optimisticResponse was provided. The writes created from the optimistic data will be rolled back before the second time this function is called which is when the mutation has succesfully resolved. At that point update will be called with the actual mutation result and those writes will not be rolled back.

Note that since this function is intended to be used to update the store, it cannot be used with a no-cache fetch policy. If you're interested in performing some action after a mutation has completed, and you don't need to update the store, use the Promise returned from client.mutate instead.

updateQueries [queryName:undefined]:(Record<, >, any) => Record<, ><><>

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.

variables TVariables

An object that maps from the name of a variable as used in the mutation GraphQL document to that variable's value.

This subscribes to a graphql subscription according to the options specified and returns an Observable which either emits received data or an error.

Options
fetchPolicy "cache-first" | "network-only" | "cache-only" | "no-cache" | "standby"

Specifies the FetchPolicy to be used for this subscription.

query DocumentNode

A GraphQL document, often created with gql from the graphql-tag package, that contains a single subscription inside of it.

variables TVariables

An object that maps from the name of a variable as used in the subscription GraphQL document to that variable's value.

Tries to read some data from the store in the shape of the provided GraphQL query without making a network request. This method will start at the root query. To start at a specific id returned by dataIdFromObject use readFragment.

Arguments
optimistic any

Set to true to allow readQuery to return optimistic results. Is false by default.

Tries to read some data from the store in the shape of the provided GraphQL fragment without making a network request. This method will read a GraphQL fragment from any arbitrary id that is currently cached, unlike readQuery which will only read from the root query.

Arguments
optimistic any

Set to true to allow readFragment to return optimistic results. Is false by default.

Options
fragment DocumentNode

A GraphQL document created using the gql template string tag from graphql-tag with one or more fragments which will be used to determine the shape of data to read. If you provide more than one fragment in this document then you must also specify fragmentName to select a single.

fragmentName any

The name of the fragment in your GraphQL document to be used. If you do not provide a fragmentName and there is only one fragment in your fragment document then that fragment will be used.

id any

The root id to be used. This id should take the same form as the value returned by your dataIdFromObject function. If a value with your id does not exist in the store, null will be returned.

variables TVariables

Any variables that your GraphQL fragments depend on.

Writes some data in the shape of the provided GraphQL query directly to the store. This method will start at the root query. To start at a specific id returned by dataIdFromObject then use writeFragment.

Options
broadcast any

Whether to notify query watchers (default: true).

data any

The data you will be writing to the store.

id any

The root id to be used. Defaults to "ROOT_QUERY", which is the ID of the root query object. This property makes writeQuery capable of writing data to any object in the cache, which renders writeFragment mostly useless.

query DocumentNode

The GraphQL query shape to be used constructed using the gql template string tag from graphql-tag. The query will be used to determine the shape of the data to be read.

variables TVariables

Any variables that the GraphQL query may depend on.

Writes some data in the shape of the provided GraphQL fragment directly to the store. This method will write to a GraphQL fragment from any arbitrary id that is currently cached, unlike writeQuery which will only write from the root query.

Options
broadcast any

Whether to notify query watchers (default: true).

data any

The data you will be writing to the store.

fragment DocumentNode

A GraphQL document created using the gql template string tag from graphql-tag with one or more fragments which will be used to determine the shape of data to read. If you provide more than one fragment in this document then you must also specify fragmentName to select a single.

fragmentName any

The name of the fragment in your GraphQL document to be used. If you do not provide a fragmentName and there is only one fragment in your fragment document then that fragment will be used.

id any

The root id to be used. This id should take the same form as the value returned by your dataIdFromObject function. If a value with your id does not exist in the store, null will be returned.

variables TVariables

Any variables that your GraphQL fragments depend on.

Resets your entire store by clearing out your cache and then re-executing all of your active queries. This makes it so that you may guarantee that there is no data left in your store from a time before you called this method.

Allows callbacks to be registered that are executed when the store is reset. onResetStore returns an unsubscribe function that can be used to remove registered callbacks.

Arguments
cb () => Promise<>

Remove all data from the store. Unlike resetStore, clearStore will not refetch any active queries.

Allows callbacks to be registered that are executed when the store is cleared. onClearStore returns an unsubscribe function that can be used to remove registered callbacks.

Arguments
cb () => Promise<>

Call this method to terminate any active client processes, making it safe to dispose of this ApolloClient instance.

Refetches all of your active queries.

Arguments
includeStandby any

Types

Properties
assumeImmutableResults any
cache ApolloCache<>
connectToDevTools any
credentials any
defaultOptions DefaultOptions
fragmentMatcher (any, any, any) => any
headers Record<, >
link ApolloLink
name any
queryDeduplication any
resolvers any
ssrForceFetchDelay any
ssrMode any
typeDefs any
uri any
version any
Properties
mutate Partial<MutationOptions>
query Partial<QueryOptions>
watchQuery Partial<WatchQueryOptions>
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