Persisted Queries

Apollo supports two separate but related features called automatic persisted queries (APQs) and persisted queries. With both features, clients can execute a GraphQL operation by sending an operation's ID instead of the entire operation string. An operation's ID is a hash of the full operation string. Querying by ID can significantly reduce latency and bandwidth usage for large operation strings.

Differences between persisted queries and APQ

The persisted queries feature requires operations to be registered in a persisted query list (PQL). This allows the PQL to act as an operation safelist made by your first-party apps. As such, persisted queries is a security feature as much as a performance one.

With APQs, if the server can't find the operation ID the client provides, the server returns an error indicating that it needs the full operation string. If an Apollo client receives this error, it automatically retries the operation with the full operation string.

If you only want to improve request latency and bandwidth usage, APQ addresses your use case. If you also want to secure your supergraph with operation safelisting, you should register operations in a PQL.

For more details on differences between persisted queries and APQ, see the GraphOS persisted queries documentation.

Implementation steps

Both persisted queries and APQs require you to configure code generation and how your client makes requests. If you intend to use persisted queries for safelisting, you also need to generate an operations manifest.

We recommend you follow this order while implementing:

The rest of this article details these steps.

Persisted queries also require you to create and link a PQL, and to configure your router to receive persisted query requests. This document only describes the steps that need to be taken by the client to create a manifest of the client's operations and send persisted query requests. For more information on the other configuration aspects of persisted queries, see the GraphOS persisted queries documentation.

0. Requirements

You can use APQ with the following versions of Apollo iOS, Apollo Server, and Apollo Router:

• Apollo iOS (v1.0.0+)
• Apollo Server (v1.0.0+)
• Apollo Router (v0.1.0+)

Using persisted queries for safelisting has the following requirements:

• Apollo iOS (v1.4.0+)
• Apollo Router (v1.25.0+)
• GraphOS Enterprise plan

1. Configure generated operation models

Both persisted queries and APQs require your code generation to include operation IDs. You can configure this in your code generation configuration's options. Specifically, set the operationDocumentFormat array to definition, operationId, or both definition and operationId.

• To use APQs, you must include both the definition and operationId.
• For persisted queries, you only need the operationId.

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"options": {
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    "operationDocumentFormat" : [
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        "definition",
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        "operationId"
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    ]
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}

2. Generate operation manifest

An operation manifest acts as a safelist of trusted operations the Apollo Router can check incoming requests against. You can generate operation manifests by adding the operationManifest option to your ApolloCodegenConfiguration JSON file like so:

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"operationManifest" : {
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  "generateManifestOnCodeGeneration" : false,
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  "path" : "/operation/identifiers/path",
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  "version" : "persistedQueries"
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}

Once these options are configured you can run the generate-operation-manifest in order to generate your operation manifest. If you have the generateManifestOnCodeGeneration flag set to true your operation manifest will also generate everytime you run the generate command.

The resulting operation manifest for persistedQueries looks like this:

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{
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  "format": "apollo-persisted-query-manifest",
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  "version": 1,
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  "operations": [
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    {
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      "id": "e0321f6b438bb42c022f633d38c19549dea9a2d55c908f64c5c6cb8403442fef",
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      "body": "query GetItem { thing { __typename } }",
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      "name": "GetItem",
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      "type": "query"
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    }
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  ]
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}

To automatically update the manifest for each new app release, you can include the generate or generate-operation-manifest command in your CI/CD pipeline.

3. Publish operation manifest

After you generate an operation manifest, you publish it to your PQL with the Rover CLI like so:

rover persisted-queries publish my-graph@my-variant \
  --manifest ./persisted-query-manifest.json

• The my-graph@my-variant argument is the graph ref of any variant the PQL is linked to.
  • Graph refs have the format graph-id@variant-name.
• Use the --manifest option to provide the path to the manifest you want to publish.

The persisted-queries publish command does the following:

1. Publishes all operations in the provided manifest file to the PQL linked to the specified variant, or to the specified PQL.

   • Publishing a manifest to a PQL is additive. Any existing entries in the PQL remain.
   • If you publish an operation with the same id but different details from an existing entry in the PQL, the entire publish command fails with an error.

2. Updates any other variants that the PQL is applied to so that routers associated with those variants can fetch their updated PQL.

As with generating manifests, it's best to execute this command in your CI/CD pipeline to publish new operations as part of your app release process. The API key you supply to Rover must have the role of Graph Admin or Persisted Query Publisher. Persisted Query Publisher is a special role designed for use with the rover persisted-queries publish command; API keys with this role have no other access to your graph's data in GraphOS, and are appropriate for sharing with trusted third party client developers who should be allowed to publish operations to your graph's PQL but should not otherwise have access to your graph.

Test operations

You can send some test operations to test that you've successfully published your manifests:

First, start your GraphOS-connected router:

APOLLO_KEY="..." APOLLO_GRAPH_REF="..." ./router --config ./router.yaml

2023-05-11T15:32:30.684460Z  INFO Apollo Router v1.18.1 // (c) Apollo Graph, Inc. // Licensed as ELv2 (https://go.apollo.dev/elv2)
2023-05-11T15:32:30.684480Z  INFO Anonymous usage data is gathered to inform Apollo product development.  See https://go.apollo.dev/o/privacy for details.
2023-05-11T15:32:31.507085Z  INFO Health check endpoint exposed at http://127.0.0.1:8088/health
2023-05-11T15:32:31.507823Z  INFO GraphQL endpoint exposed at http://127.0.0.1:4000/ 🚀

Next, make a POST request with curl, like so:

curl http://localhost:4000 -X POST --json \
'{"extensions":{"persistedQuery":{"version":1,"sha256Hash":"dc67510fb4289672bea757e862d6b00e83db5d3cbbcfb15260601b6f29bb2b8f"}}}'

If your router's PQL includes an operation with an ID that matches the value of the provided sha256Hash property, it executes the corresponding operation and returns its result.

4. Enable persisted queries on ApolloClient

Once you've configured your code generation to include operation IDs, you can update your client to query by operation ID rather than the full operation string. This configuration is the same whether you're using APQ or persisted queries:

• Initialize a custom NetworkTransport using RequestChainNetworkTransport with autoPersistQueries parameter set to true and an interceptorProvider that includes the AutomaticPersistedQueryInterceptor (such as DefaultInterceptorProvider).
• Initialize your ApolloClient with the custom NetworkTransport that supports persisted queries.

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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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    autoPersistQueries: true
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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.

Sending APQ retries as GET requests

By default, the Apollo clients sends operation retries as POST requests. In some cases, you may prefer or need to retry an operation using a GET request: for example, you may make requests to a CDN that has better performance with GETs.

To use GET for APQ retry requests, set the useGETForPersistedQueryRetry on your RequestChainNetworkTransport to true.

In most cases, keeping the default option (false) suffices.