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.play:engage:1.5.0-alpha'
}
To make the Engage SDK function for devices with Android 11 and above, declare the following in the manifest file:
<queries>
<package android:name="com.android.vending" />
</queries>
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:
EbookEntityAudiobookEntityBookSeriesEntity
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. |
| 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. |
| 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. Integer between 0 and 100. |
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. |
| 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. |
| 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. Integer between 0 and 100. |
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. |
| 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. |
| 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. Integer between 0 and 100. |
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 clients. There are five
APIs to publish clusters in the client:
isServiceAvailablepublishRecommendationClusterspublishFeaturedClusterpublishContinuationClusterdeleteClusters
API #1: isServiceAvailable
This API is used to check if the service is available for integration and whether the content can be presented on the device.
Task<Boolean> isAvailableTask = client.isServiceAvailable();
isAvailableTask.addOnCompleteListener(task - > {
if (resultTask.isSuccessful()) {
// Handle success
}
});
API #2: publishRecommendationClusters
This API is used to publish a list of RecommendationCluster objects.
Task<Void> task =
client.publishRecommendationClusters(
new PublishRecommendationClustersRequest.Builder()
.addRecommendationCluster(
new RecommendationCluster.Builder()
.addEntity(book_entity1)
.addEntity(book_entity2)
.setTitle("Reconnect with yourself")
.build())
.build());
When the service receives the request, the following actions take place within one transaction:
- Existing
RecommendationClusterdata 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.
API #3: publishFeaturedCluster
This API is used to publish a list of FeaturedCluster objects.
Task<Void> task =
client.publishFeaturedCluster(
new PublishFeaturedClustersRequest.Builder()
.addFeaturedCluster(
new FeaturedCluster.Builder()
.addEntity(book_entity1)
.addEntity(book_entity2)
.build())
.build());
When the service receives the request, the following actions take place within one transaction:
- Existing
FeaturedClusterdata 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.
API #4: publishContinuationCluster
This API is used to publish a ContinuationCluster object.
Task<Void> task =
client.publishContinuationCluster(
new PublishContinuationClusterRequest.Builder()
.setContinuationCluster(
new 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
ContinuationClusterdata 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.
API #5: deleteClusters
This API is used to delete the content of a given cluster type.
Task<Void> task =
client.deleteClusters(
new DeleteClustersRequest.Builder()
.addClusterType(ClusterType.TYPE_CONTINUATION)
.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
BroadcastReceiverclass usingContext.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.play.engage.service.Intents.ACTION_PUBLISH_RECOMMENDATION));
// Register Featured Cluster Publish Intent
context.registerReceiver(new AppEngageBroadcastReceiver(),
new IntentFilter(com.google.android.play.engage.service.Intents.ACTION_PUBLISH_FEATURED));
// Register Continuation Cluster Publish Intent
context.registerReceiver(new AppEngageBroadcastReceiver(),
new IntentFilter(com.google.android.play.engage.service.Intents.ACTION_PUBLISH_CONTINUATION));
}
- Statically declare an implementation with the
<receiver>tag in yourAndroidManifest.xmlfile. 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.play.engage.action.PUBLISH_RECOMMENDATION" />
</intent-filter>
<intent-filter>
<action android:name="com.google.android.play.engage.action.PUBLISH_FEATURED" />
</intent-filter>
<intent-filter>
<action android:name="com.google.android.play.engage.action.PUBLISH_CONTINUATION" />
</intent-filter>
</receiver>
</application>
The following intents will be sent by the service:
com.google.android.play.engage.action.PUBLISH_RECOMMENDATIONIt is recommended to start apublishRecommendationClusterscall when receiving this intent.com.google.android.play.engage.action.PUBLISH_FEATUREDIt is recommended to start apublishFeaturedClustercall when receiving this intent.- com.google.android.play.engage.action.PUBLISH_CONTINUATION
It 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.