# android.app.appsearch.observer

# android.app.appsearch.observer

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Kotlin\|[Java](https://developer.android.com/reference/android/app/appsearch/observer/package-summary "View this page in Java")

## Interfaces

|--------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------|
| [ObserverCallback](https://developer.android.com/reference/kotlin/android/app/appsearch/observer/ObserverCallback) | An interface which apps can implement to subscribe to notifications of changes to AppSearch data. |

## Classes

|------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [DocumentChangeInfo](https://developer.android.com/reference/kotlin/android/app/appsearch/observer/DocumentChangeInfo) | Contains information about an individual change detected by an[ObserverCallback](https://developer.android.com/reference/kotlin/android/app/appsearch/observer/ObserverCallback).                    |
| [ObserverSpec](https://developer.android.com/reference/kotlin/android/app/appsearch/observer/ObserverSpec)             | Configures the types, namespaces and other properties that[ObserverCallback](https://developer.android.com/reference/kotlin/android/app/appsearch/observer/ObserverCallback)instances match against. |
| [SchemaChangeInfo](https://developer.android.com/reference/kotlin/android/app/appsearch/observer/SchemaChangeInfo)     | Contains information about a schema change detected by an[ObserverCallback](https://developer.android.com/reference/kotlin/android/app/appsearch/observer/ObserverCallback).                         |