Automatic Persisted Queries

Apollo Server allows you to use a feature called Automatic Persisted Queries, or APQs, to avoiding sending the same large query documents over and over.

Each query or mutation is identified by the SHA256 hash of its contents. If the hash can't be found by the server, it sends back an error indicating that it needs the full query. If it receives this specific error, Apollo iOS will automatically retry the operation with the full query document without you having to do anything.

Using APQs with Apollo iOS

To enable APQs you must configure code generation and your ApolloClient correctly.

1. Configure code generation to APQ compatible operations

In order to use APQs, your operations must have SHA256 hash identifiers included in the generated operation objects. To configure code generation to include these identifiers, set the ApolloCodegenConfiguration's options.apqs to .automaticallyPersist.

To set this property in your apollo-codegen-config.json file, add set the options.apqs property in the JSON to "automaticallyPersist":

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"options" {
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    "apqs": "automaticallyPersist"
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}

2. Enable APQs on your ApolloClient

You must also initialize your ApolloClient, with a custom NetworkTransport that supports APQs.

Initialize a RequestChainNetworkTransport with autoPersistQueries parameter set to true and an interceptorProvider that includes the AutomaticPersistedQueryInterceptor (such as DefaultInterceptorProvider).

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let store = ApolloStore(cache: InMemoryNormalizedCache())
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let interceptorProvider = DefaultInterceptorProvider(store: store)
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let networkTransport = RequestChainNetworkTransport(
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    interceptorProvider: interceptorProvider,
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    endpointURL: URL(string: "http://localhost:4000/graphql")!
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)
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let client = ApolloClient(networkTransport: networkTransport, store: store)

For more information on configuring your ApolloClient, NetworkTransport, InterceptorProvider, and the request chain, see the Request Pipeline documentation.

Send APQs as GET requests

By default, retries of queries will use POST. In some cases, it may be required or preferred to retry persisted operation using a GET request (for example, when your queries are hitting a CDN that has better performance with GET).

In order to use GET for persisted query retry requests, set the useGETForPersistedQueryRetry on your RequestChainNetworkTransport to true.

Most users will want to leave this option as false.