Engage SDK Read: Third-party technical integration instructions

Google is building an on-device surface that organizes users' apps by verticals and enables a new immersive experience for personalized app content consumption and discovery. This fullscreen experience provides developer partners with an opportunity to showcase their best rich content in a dedicated channel outside of their app.

This guide contains instructions for developer partners to integrate their readable content, using the Engage SDK to populate both this new surface area and existing Google surfaces.

Integration detail

Terminology

This integration includes the following three cluster types: Recommendation, Continuation, and Featured.

  • Recommendation clusters show personalized suggestions for content to read from an individual developer partner.

    Your recommendations take the following structure:

    • Recommendation Cluster: A UI view that contains a group of recommendations from a single developer partner.

      Figure 1. Entertainment Space UI showing a Recommendation Cluster from a single partner.
    • Entity: An object representing a single item in a cluster. An entity can be an ebook, an audio book, a book series, and more. See the Provide entity data section for a list of supported entity types.

      Figure 2. Entertainment Space UI showing a single Entity within a single partner's Recommendation Cluster.
  • The Continuation cluster shows unfinished books from multiple developer partners in a single UI grouping. Each developer partner will be allowed to broadcast a maximum of 10 entities in the Continuation cluster.

    Figure 3. Entertainment Space UI showing a Continuation cluster with unfinished recommendations from multiple partners (only one recommendation is currently visible).
  • The Featured cluster showcases a selection of items from multiple developer partners in a single UI grouping. There will be a single Featured cluster, which is surfaced near the top of the UI with a priority placement above all Recommendation clusters. Each developer partner will be allowed to broadcast up to 10 entities in the Featured cluster.

    Figure 4. Entertainment Space UI showing a Featured cluster with recommendations from multiple partners (only one recommendation is currently visible).

Pre-work

Minimum API level: 19

Add the com.google.android.play:engage library to your app:

dependencies {
    // Make sure you also include that repository in your project's build.gradle file.
    implementation 'com.google.android.engage:engage-core:1.4.0'
}

Summary

The design is based on an implementation of a bound service.

The data a client can publish is subject to the following limits for different cluster types:

Cluster type Cluster limits Maximum entity limits in a cluster
Recommendation Cluster(s) At most 5 At most 50
Continuation Cluster At most 1 At most 10
Featured Cluster At most 1 At most 10

Step 1: Provide entity data

The SDK has defined different entities to represent each item type. We support the following entities for the Read category:

  1. EbookEntity
  2. AudiobookEntity
  3. BookSeriesEntity

The charts below outline available attributes and requirements for each type.

EbookEntity

The EbookEntity object represents an ebook (for example, the ebook of Becoming by Michelle Obama).

Attribute Requirement Notes
Name Required
Poster images Required At least one image must be provided. See Image Specifications for guidance.
Author Required At least one author name must be provided.
Action link uri Required

The deep link to the provider app for the ebook.

Note: You can use deep links for attribution. Refer to this FAQ

Publish date Optional In epoch milliseconds if provided.
Description Optional Must be within 200 characters if provided.
Price Optional Free text
Page count Optional Must be a positive integer if provided.
Genre Optional List of genres associated with the book.
Series name Optional Name of the series that the ebook belongs to (for example, Harry Potter).
Series unit index Optional The index of the ebook in the series, where 1 is the first ebook in the series. For example, if Harry Potter and the Prisoner of Azkaban is the 3rd book in the series, this should be set to 3.
Continue book type Optional

TYPE_CONTINUE - Resume on a unfinished book.

TYPE_NEXT - Continue on a new one of a series.

TYPE_NEW - Newly released.

Last Engagement Time Conditionally required

Must be provided when the item is in the Continuation cluster.

*Newly* acquired ebooks can be a part of the continue reading cluster.

In epoch milliseconds.

Progress Percentage Complete Conditionally required

Must be provided when the item is in the Continuation cluster.

Value must be greater than 0 and less than 100.

DisplayTimeWindow - Set a time window for a content to be shown on the surface
Start Timestamp Optional

The epoch timestamp after which the content should be shown on the surface.

If not set, content is eligible to be shown on the surface.

In epoch milliseconds.

End Timestamp Optional

The epoch timestamp after which the content is no longer be shown on the surface.

If not set, content is eligible to be shown on the surface.

In epoch milliseconds.

AudiobookEntity

The AudiobookEntity object represents an audiobook (for example, the audiobook of Becoming by Michelle Obama).

Attribute Requirement Notes
Name Required
Poster images Required At least one image must be provided. See Image Specifications for guidance.
Author Required At least one author name must be provided.
Narrator Required At least one narrator's name must be provided.
Action link uri Required

The deep link to the provider app for the audiobook.

Note: You can use deep links for attribution. Refer to this FAQ

Publish date Optional In epoch milliseconds if provided.
Description Optional Must be within 200 characters if provided.
Price Optional Free text
Duration Optional Must be a positive value if provided.
Genre Optional List of genres associated with the book.
Series name Optional Name of the series that the audiobook belongs to (for example, Harry Potter.
Series unit index Optional The index of the audiobook in the series, where 1 is the first audiobook in the series. For example, if Harry Potter and the Prisoner of Azkaban is the 3rd book in the series, this should be set to 3.
Continue book type Optional

TYPE_CONTINUE - Resume on a unfinished book.

TYPE_NEXT - Continue on a new one of a series.

TYPE_NEW - Newly released.

Last Engagement Time Conditionally required

Must be provided when the item is in the Continuation cluster.

In epoch milliseconds.

Progress Percentage Complete Conditionally required

Must be provided when the item is in the Continuation cluster.

*Newly* acquired audiobooks can be a part of the continue reading cluster.

Value must be greater than 0 and less than 100.

DisplayTimeWindow - Set a time window for a content to be shown on the surface
Start Timestamp Optional

The epoch timestamp after which the content should be shown on the surface.

If not set, content is eligible to be shown on the surface.

In epoch milliseconds.

End Timestamp Optional

The epoch timestamp after which the content is no longer be shown on the surface.

If not set, content is eligible to be shown on the surface.

In epoch milliseconds.

BookSeriesEntity

The BookSeriesEntity object represents a book series (for example, the Harry Potter book series, which has 7 books).

Attribute Requirement Notes
Name Required
Poster images Required At least one image must be provided. See Image Specifications for guidance.
Author Required At least one author name must be present.
Action link uri Required

The deep link to the provider app for the audiobook or ebook.

Note: You can use deep links for attribution. Refer to this FAQ

Book count Required Number of books in the series.
Description Optional Must be within 200 characters if provided.
Genre Optional List of genres associated with the book.
Continue book type Optional

TYPE_CONTINUE - Resume on a unfinished book.

TYPE_NEXT - Continue on a new one of a series.

TYPE_NEW - Newly released.

Last Engagement Time Conditionally required

Must be provided when the item is in the Continuation cluster.

In epoch milliseconds.

Progress Percentage Complete Conditionally required

Must be provided when the item is in the Continuation cluster.

*Newly* acquired book series can be a part of the continue reading cluster.

Value must be greater than 0 and less than 100.

DisplayTimeWindow - Set a time window for a content to be shown on the surface
Start Timestamp Optional

The epoch timestamp after which the content should be shown on the surface.

If not set, content is eligible to be shown on the surface.

In epoch milliseconds.

End Timestamp Optional

The epoch timestamp after which the content is no longer be shown on the surface.

If not set, content is eligible to be shown on the surface.

In epoch milliseconds.

Image specifications

Required specifications for image assets are listed below:

Aspect ratio Requirement Minimum pixels Recommended pixels
Square (1x1) Required 300x300 1200x1200
Landscape (1.91x1) Optional 600x314 1200x628
Portrait (4x5) Optional 480x600 960x1200

File formats

PNG, JPG, static GIF, WebP

Maximum file size

5120 KB

Additional recommendations

  • Image safe area: Put your important content in the center 80% of the image.

Example

AudiobookEntity audiobookEntity =
        new AudiobookEntity.Builder()
            .setName("Becoming")
            .addPosterImage(
                      new Image.Builder()
                          .setImageUri(Uri.parse("http://www.x.com/image.png"))
                          .setImageHeightInPixel(960)
                          .setImageWidthInPixel(408)
                          .build())
            .addAuthor("Michelle Obama")
            .addNarrator("Michelle Obama")
            .setActionLinkUri(Uri.parse("https://play.google/audiobooks/1"))
            .setDurationMillis(16335L)
            .setPublishDateEpochMillis(1633032895L)
            .setDescription("An intimate, powerful, and inspiring memoir")
            .setPrice("$16.95")
            .addGenre("biography")
            .build();

Step 2: Provide Cluster data

It's recommended to have the content publish job executed in the background (for example, using WorkManager) and scheduled on a regular basis or on an event basis (for example, every time the user opens the app or when the user just added something to their cart).

AppEngagePublishClient is responsible for publishing clusters. Following APIs are available in the client:

  • isServiceAvailable
  • publishRecommendationClusters
  • publishFeaturedCluster
  • publishContinuationCluster
  • publishUserAccountManagementRequest
  • updatePublishStatus
  • deleteRecommendationsClusters
  • deleteFeaturedCluster
  • deleteContinuationCluster
  • deleteUserManagementCluster
  • deleteClusters

isServiceAvailable

This API is used to check if the service is available for integration and whether the content can be presented on the device.

Kotlin


client.isServiceAvailable.addOnCompleteListener { task ->
    if (task.isSuccessful) {
        // Handle IPC call success
        if(task.result) {
          // Service is available on the device, proceed with content
          // publish calls.
        } else {
          // Service is not available, no further action is needed.
        }
    } else {
      // The IPC call itself fails, proceed with error handling logic here,
      // such as retry.
    }
}

Java


client.isServiceAvailable().addOnCompleteListener(task - > {
    if (task.isSuccessful()) {
        // Handle success
        if(task.getResult()) {
          // Service is available on the device, proceed with content publish
          // calls.
        } else {
          // Service is not available, no further action is needed.
        }
    } else {
      // The IPC call itself fails, proceed with error handling logic here,
      // such as retry.
    }
});

publishRecommendationClusters

This API is used to publish a list of RecommendationCluster objects.

Kotlin


client.publishRecommendationClusters(
            PublishRecommendationClustersRequest.Builder()
                .addRecommendationCluster(
                    RecommendationCluster.Builder()
                        .addEntity(entity1)
                        .addEntity(entity2)
                        .setTitle("Reconnect with yourself")
                        .build())
                .build())

Java


client.publishRecommendationClusters(
            new PublishRecommendationClustersRequest.Builder()
                .addRecommendationCluster(
                    new RecommendationCluster.Builder()
                        .addEntity(entity1)
                        .addEntity(entity2)
                        .setTitle("Reconnect with yourself")
                        .build())
                .build());

When the service receives the request, the following actions take place within one transaction:

  • Existing RecommendationCluster data from the developer partner is removed.
  • Data from the request is parsed and stored in the updated Recommendation Cluster.

In case of an error, the entire request is rejected and the existing state is maintained.

publishFeaturedCluster

This API is used to publish a list of FeaturedCluster objects.

Kotlin


client.publishFeaturedCluster(
            PublishFeaturedClusterRequest.Builder()
                .setFeaturedCluster(
                    FeaturedCluster.Builder()
                        ...
                        .build())
                .build())

Java


client.publishFeaturedCluster(
            new PublishFeaturedClusterRequest.Builder()
                .setFeaturedCluster(
                    new FeaturedCluster.Builder()
                        ...
                        .build())
                .build());

When the service receives the request, the following actions take place within one transaction:

  • Existing FeaturedCluster data from the developer partner is removed.
  • Data from the request is parsed and stored in the updated Featured Cluster.

In case of an error, the entire request is rejected and the existing state is maintained.

publishContinuationCluster

This API is used to publish a ContinuationCluster object.

Kotlin


client.publishContinuationCluster(
            PublishContinuationClusterRequest.Builder()
                .setContinuationCluster(
                    ContinuationCluster.Builder()
                        .addEntity(book_entity1)
                        .addEntity(book_entity2)
                        .build())
                .build())

Java


client.publishContinuationCluster(
            PublishContinuationClusterRequest.Builder()
                .setContinuationCluster(
                    ContinuationCluster.Builder()
                        .addEntity(book_entity1)
                        .addEntity(book_entity2)
                        .build())
                .build())

When the service receives the request, the following actions take place within one transaction:

  • Existing ContinuationCluster data from the developer partner is removed.
  • Data from the request is parsed and stored in the updated Continuation Cluster.

In case of an error, the entire request is rejected and the existing state is maintained.

publishUserAccountManagementRequest

This API is used to publish a Sign In card . The signin action directs users to the app's sign in page so that the app can publish content (or provide more personalized content)

The following metadata is part of the Sign In Card -

Attribute Requirement Description
Action Uri Required Deeplink to Action (i.e. navigates to app sign in page)
Image Optional - If not provided, Title must be provided

Image Shown on the Card

16x9 aspect ratio images with a resolution of 1264x712

Title Optional - If not provided, Image must be provided Title on the Card
Action Text Optional Text Shown on the CTA (i.e. Sign in)
Subtitle Optional Optional Subtitle on the Card

Kotlin


var SIGN_IN_CARD_ENTITY =
      SignInCardEntity.Builder()
          .addPosterImage(
              Image.Builder()
                  .setImageUri(Uri.parse("http://www.x.com/image.png"))
                  .setImageHeightInPixel(500)
                  .setImageWidthInPixel(500)
                  .build())
          .setActionText("Sign In")
          .setActionUri(Uri.parse("http://xx.com/signin"))
          .build()

client.publishUserAccountManagementRequest(
            PublishUserAccountManagementRequest.Builder()
                .setSignInCardEntity(SIGN_IN_CARD_ENTITY)
                .build());

Java


SignInCardEntity SIGN_IN_CARD_ENTITY =
      new SignInCardEntity.Builder()
          .addPosterImage(
              new Image.Builder()
                  .setImageUri(Uri.parse("http://www.x.com/image.png"))
                  .setImageHeightInPixel(500)
                  .setImageWidthInPixel(500)
                  .build())
          .setActionText("Sign In")
          .setActionUri(Uri.parse("http://xx.com/signin"))
          .build();

client.publishUserAccountManagementRequest(
            new PublishUserAccountManagementRequest.Builder()
                .setSignInCardEntity(SIGN_IN_CARD_ENTITY)
                .build());

When the service receives the request, the following actions take place within one transaction:

  • Existing UserAccountManagementCluster data from the developer partner is removed.
  • Data from the request is parsed and stored in the updated UserAccountManagementCluster Cluster.

In case of an error, the entire request is rejected and the existing state is maintained.

updatePublishStatus

If for any internal business reason, none of the clusters is published, we strongly recommend updating the publish status using the updatePublishStatus API. This is important because :

  • Providing the status in all scenarios, even when the content is published (STATUS == PUBLISHED), is critical to populate dashboards that use this explicit status to convey the health and other metrics of your integration.
  • If no content is published but the integration status isn't broken (STATUS == NOT_PUBLISHED), Google can avoid triggering alerts in the app health dashboards. It confirms that content is not published due to an expected situation from the provider's standpoint.
  • It helps developers provide insights into when the data is published vs not.
  • Google may use the status codes to nudge the user to do certain actions in the app so they can see the app content or overcome it.

The list of eligible publish status codes are :

// Content is published
AppEngagePublishStatusCode.PUBLISHED,

// Content is not published as user is not signed in
AppEngagePublishStatusCode.NOT_PUBLISHED_REQUIRES_SIGN_IN,

// Content is not published as user is not subscribed
AppEngagePublishStatusCode.NOT_PUBLISHED_REQUIRES_SUBSCRIPTION,

// Content is not published as user location is ineligible
AppEngagePublishStatusCode.NOT_PUBLISHED_INELIGIBLE_LOCATION,

// Content is not published as there is no eligible content
AppEngagePublishStatusCode.NOT_PUBLISHED_NO_ELIGIBLE_CONTENT,

// Content is not published as the feature is disabled by the client
// Available in v1.3.1
AppEngagePublishStatusCode.NOT_PUBLISHED_FEATURE_DISABLED_BY_CLIENT,

// Content is not published as the feature due to a client error
// Available in v1.3.1
AppEngagePublishStatusCode.NOT_PUBLISHED_CLIENT_ERROR,

// Content is not published as the feature due to a service error
// Available in v1.3.1
AppEngagePublishStatusCode.NOT_PUBLISHED_SERVICE_ERROR,

// Content is not published due to some other reason
// Reach out to engage-developers@ before using this enum.
AppEngagePublishStatusCode.NOT_PUBLISHED_OTHER

If the content is not published due to a user not logged in, Google would recommend publishing the Sign In Card. If for any reason providers are not able to publish the Sign In Card then we recommend calling the updatePublishStatus API with the status code NOT_PUBLISHED_REQUIRES_SIGN_IN

Kotlin


client.updatePublishStatus(
   PublishStatusRequest.Builder()
     .setStatusCode(AppEngagePublishStatusCode.NOT_PUBLISHED_REQUIRES_SIGN_IN)
     .build())

Java


client.updatePublishStatus(
    new PublishStatusRequest.Builder()
        .setStatusCode(AppEngagePublishStatusCode.NOT_PUBLISHED_REQUIRES_SIGN_IN)
        .build());

deleteRecommendationClusters

This API is used to delete the content of Recommendation Clusters.

Kotlin


client.deleteRecommendationClusters()

Java


client.deleteRecommendationClusters();

When the service receives the request, it removes the existing data from the Recommendation Clusters. In case of an error, the entire request is rejected and the existing state is maintained.

deleteFeaturedCluster

This API is used to delete the content of Featured Cluster.

Kotlin


client.deleteFeaturedCluster()

Java


client.deleteFeaturedCluster();

When the service receives the request, it removes the existing data from the Featured Cluster. In case of an error, the entire request is rejected and the existing state is maintained.

deleteContinuationCluster

This API is used to delete the content of Continuation Cluster.

Kotlin


client.deleteContinuationCluster()

Java


client.deleteContinuationCluster();

When the service receives the request, it removes the existing data from the Continuation Cluster. In case of an error, the entire request is rejected and the existing state is maintained.

deleteUserManagementCluster

This API is used to delete the content of UserAccountManagement Cluster.

Kotlin


client.deleteUserManagementCluster()

Java


client.deleteUserManagementCluster();

When the service receives the request, it removes the existing data from the UserAccountManagement Cluster. In case of an error, the entire request is rejected and the existing state is maintained.

deleteClusters

This API is used to delete the content of a given cluster type.

Kotlin


client.deleteClusters(
    DeleteClustersRequest.Builder()
      .addClusterType(ClusterType.TYPE_FEATURED)
      .addClusterType(ClusterType.TYPE_RECOMMENDATION)
      ...
      .build())

Java


client.deleteClusters(
            new DeleteClustersRequest.Builder()
                .addClusterType(ClusterType.TYPE_FEATURED)
                .addClusterType(ClusterType.TYPE_RECOMMENDATION)
                ...
                .build());

When the service receives the request, it removes the existing data from all clusters matching the specified cluster types. Clients can choose to pass one or many cluster types. In case of an error, the entire request is rejected and the existing state is maintained.

Error handling

It is highly recommended to listen to the task result from the publish APIs such that a follow-up action can be taken to recover and resubmit an successful task.

client.publishRecommendationClusters(
              new PublishRecommendationClustersRequest.Builder()
                  .addRecommendationCluster(...)
                  .build())
          .addOnCompleteListener(
              task -> {
                if (task.isSuccessful()) {
                  // do something
                } else {
                  Exception exception = task.getException();
                  if (exception instanceof AppEngageException) {
                    @AppEngageErrorCode
                    int errorCode = ((AppEngageException) exception).getErrorCode();
                    if (errorCode == AppEngageErrorCode.SERVICE_NOT_FOUND) {
                      // do something
                    }
                  }
                }
              });

The error is returned as an AppEngageException with the cause included as an error code.

Error code Note
SERVICE_NOT_FOUND The service is not available on the given device.
SERVICE_NOT_AVAILABLE The service is available on the given device, but it is not available at the time of the call (for example, it is explicitly disabled).
SERVICE_CALL_EXECUTION_FAILURE The task execution failed due to threading issues. In this case, it can be retried.
SERVICE_CALL_PERMISSION_DENIED The caller is not allowed to make the service call.
SERVICE_CALL_INVALID_ARGUMENT The request contains invalid data (for example, more than the allowed number of clusters).
SERVICE_CALL_INTERNAL There is an error on the service side.
SERVICE_CALL_RESOURCE_EXHAUSTED The service call is made too frequently.

Step 3: Handle broadcast intents

In addition to making publish content API calls through a job, it is also required to set up a BroadcastReceiver to receive the request for a content publish.

The goal of broadcast intents is mainly for app reactivation and forcing data sync. Broadcast intents are not designed to be sent very frequently. It is only triggered when the Engage Service determines the content might be stale (for example, a week old). That way, there is more confidence that the user can have a fresh content experience, even if the application has not been executed for a long period of time.

The BroadcastReceiver must be set up in the following two ways:

  • Dynamically register an instance of the BroadcastReceiver class using Context.registerReceiver(). This enables communication from applications that are still live in memory.
class AppEngageBroadcastReceiver extends BroadcastReceiver {
// Trigger recommendation cluster publish when PUBLISH_RECOMMENDATION broadcast
// is received

// Trigger featured cluster publish when PUBLISH_FEATURED broadcast is received

// Trigger continuation cluster publish when PUBLISH_CONTINUATION broadcast is
// received
}

public static void registerBroadcastReceivers(Context context) {

context = context.getApplicationContext();

// Register Recommendation Cluster Publish Intent
context.registerReceiver(new AppEngageBroadcastReceiver(),
new IntentFilter(com.google.android.engage.service.Intents.ACTION_PUBLISH_RECOMMENDATION));

// Register Featured Cluster Publish Intent
context.registerReceiver(new AppEngageBroadcastReceiver(),
new IntentFilter(com.google.android.engage.service.Intents.ACTION_PUBLISH_FEATURED));


// Register Continuation Cluster Publish Intent
context.registerReceiver(new AppEngageBroadcastReceiver(),
new IntentFilter(com.google.android.engage.service.Intents.ACTION_PUBLISH_CONTINUATION));

}
  • Statically declare an implementation with the <receiver> tag in your AndroidManifest.xml file. This allows the application to receive broadcast intents when it is not running, and also allows the application to publish the content.
<application>
   <receiver
      android:name=".AppEngageBroadcastReceiver"
      android:exported="true"
      android:enabled="true">
      <intent-filter>
         <action android:name="com.google.android.engage.action.PUBLISH_RECOMMENDATION" />
      </intent-filter>
      <intent-filter>
         <action android:name="com.google.android.engage.action.PUBLISH_FEATURED" />
      </intent-filter>
      <intent-filter>
         <action android:name="com.google.android.engage.action.PUBLISH_CONTINUATION" />
      </intent-filter>
   </receiver>
</application>

The following intents will be sent by the service:

  • com.google.android.engage.action.PUBLISH_RECOMMENDATION It is recommended to start a publishRecommendationClusters call when receiving this intent.
  • com.google.android.engage.action.PUBLISH_FEATURED It is recommended to start a publishFeaturedCluster call when receiving this intent.
  • com.google.android.engage.action.PUBLISH_CONTINUATIONIt is recommended to start apublishContinuationCluster` call when receiving this intent.

Integration workflow

For a step-by-step guide on verifying your integration after it is complete, see Engage developer integration workflow.

FAQs

See Engage SDK Frequently Asked Questions for FAQs.

Contact

Please contact engage-developers@google.com if there are any questions during the integration process. Our team will reply as soon as possible.

Next steps

After completing this integration, your next steps are as follows:

  • Send an email to engage-developers@google.com and attach your integrated APK that is ready for testing by Google.
  • Google will perform a verification and review internally to make sure the integration works as expected. If changes are needed, Google will contact you with any necessary details.
  • When testing is complete and no changes are needed, Google will contact you to notify you that you can start publishing the updated and integrated APK to the Play Store.
  • After Google has confirmed that your updated APK has been published to the Play Store, your Recommendation, Featured, and Continuation clusters will be published and visible to users.