diff --git a/api/current.txt b/api/current.txt
index 10d55f5cb39a6..d4b0c27680738 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -41546,6 +41546,7 @@ package android.service.notification {
     field public static final android.os.Parcelable.Creator<android.service.notification.Adjustment> CREATOR;
     field public static final String KEY_CONTEXTUAL_ACTIONS = "key_contextual_actions";
     field public static final String KEY_IMPORTANCE = "key_importance";
+    field public static final String KEY_SNOOZE_CRITERIA = "key_snooze_criteria";
     field public static final String KEY_TEXT_REPLIES = "key_text_replies";
     field public static final String KEY_USER_SENTIMENT = "key_user_sentiment";
   }
@@ -41603,12 +41604,14 @@ package android.service.notification {
     method public void onActionInvoked(@NonNull String, @NonNull android.app.Notification.Action, int);
     method public final android.os.IBinder onBind(android.content.Intent);
     method public void onNotificationDirectReplied(@NonNull String);
-    method public android.service.notification.Adjustment onNotificationEnqueued(android.service.notification.StatusBarNotification);
+    method public abstract android.service.notification.Adjustment onNotificationEnqueued(android.service.notification.StatusBarNotification);
     method public android.service.notification.Adjustment onNotificationEnqueued(android.service.notification.StatusBarNotification, android.app.NotificationChannel);
     method public void onNotificationExpansionChanged(@NonNull String, boolean, boolean);
     method public void onNotificationRemoved(android.service.notification.StatusBarNotification, android.service.notification.NotificationListenerService.RankingMap, android.service.notification.NotificationStats, int);
+    method public abstract void onNotificationSnoozedUntilContext(android.service.notification.StatusBarNotification, String);
     method public void onNotificationsSeen(java.util.List<java.lang.String>);
     method public void onSuggestedReplySent(@NonNull String, @NonNull CharSequence, int);
+    method public final void unsnoozeNotification(String);
     field public static final String SERVICE_INTERFACE = "android.service.notification.NotificationAssistantService";
     field public static final int SOURCE_FROM_APP = 0; // 0x0
     field public static final int SOURCE_FROM_ASSISTANT = 1; // 0x1
diff --git a/api/system-current.txt b/api/system-current.txt
index c9b8c3867e592..c185f3c9afb76 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -6500,6 +6500,15 @@ package android.service.euicc {
 
 package android.service.notification {
 
+  public final class Adjustment implements android.os.Parcelable {
+    ctor protected Adjustment(android.os.Parcel);
+    field public static final String KEY_PEOPLE = "key_people";
+  }
+
+  public final class NotificationStats implements android.os.Parcelable {
+    ctor protected NotificationStats(android.os.Parcel);
+  }
+
   public final class SnoozeCriterion implements android.os.Parcelable {
     ctor public SnoozeCriterion(String, CharSequence, CharSequence);
     ctor protected SnoozeCriterion(android.os.Parcel);
diff --git a/core/java/android/service/notification/Adjustment.java b/core/java/android/service/notification/Adjustment.java
index 93189b310485f..2961426278dc9 100644
--- a/core/java/android/service/notification/Adjustment.java
+++ b/core/java/android/service/notification/Adjustment.java
@@ -15,6 +15,7 @@
  */
 package android.service.notification;
 
+import android.annotation.SystemApi;
 import android.app.Notification;
 import android.os.Bundle;
 import android.os.Parcel;
@@ -36,13 +37,13 @@ public final class Adjustment implements Parcelable {
      * See {@link android.app.Notification.Builder#addPerson(String)}.
      * @hide
      */
+    @SystemApi
     public static final String KEY_PEOPLE = "key_people";
     /**
      * Parcelable {@code ArrayList} of {@link SnoozeCriterion}. These criteria may be visible to
      * users. If a user chooses to snooze a notification until one of these criterion, the
      * assistant will be notified via
      * {@link NotificationAssistantService#onNotificationSnoozedUntilContext}.
-     * @hide
      */
     public static final String KEY_SNOOZE_CRITERIA = "key_snooze_criteria";
     /**
@@ -111,7 +112,11 @@ public final class Adjustment implements Parcelable {
         mUser = user;
     }
 
-    private Adjustment(Parcel in) {
+    /**
+     * @hide
+     */
+    @SystemApi
+    protected Adjustment(Parcel in) {
         if (in.readInt() == 1) {
             mPackage = in.readString();
         } else {
diff --git a/core/java/android/service/notification/NotificationAssistantService.java b/core/java/android/service/notification/NotificationAssistantService.java
index e93b1580bc660..a697248606343 100644
--- a/core/java/android/service/notification/NotificationAssistantService.java
+++ b/core/java/android/service/notification/NotificationAssistantService.java
@@ -21,6 +21,7 @@ import static java.lang.annotation.RetentionPolicy.SOURCE;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.SdkConstant;
+import android.annotation.SystemApi;
 import android.app.Notification;
 import android.app.NotificationChannel;
 import android.app.admin.DevicePolicyManager;
@@ -103,7 +104,6 @@ public abstract class NotificationAssistantService extends NotificationListenerS
      *
      * @param sbn the notification to snooze
      * @param snoozeCriterionId the {@link SnoozeCriterion#getId()} representing a device context.
-     * @hide
      */
     abstract public void onNotificationSnoozedUntilContext(StatusBarNotification sbn,
             String snoozeCriterionId);
@@ -111,12 +111,13 @@ public abstract class NotificationAssistantService extends NotificationListenerS
     /**
      * A notification was posted by an app. Called before post.
      *
+     * <p>Note: this method is only called if you don't override
+     * {@link #onNotificationEnqueued(StatusBarNotification, NotificationChannel)}.</p>
+     *
      * @param sbn the new notification
      * @return an adjustment or null to take no action, within 100ms.
      */
-    public Adjustment onNotificationEnqueued(StatusBarNotification sbn) {
-        return null;
-    }
+    abstract public Adjustment onNotificationEnqueued(StatusBarNotification sbn);
 
     /**
      * A notification was posted by an app. Called before post.
@@ -240,12 +241,11 @@ public abstract class NotificationAssistantService extends NotificationListenerS
     /**
      * Inform the notification manager about un-snoozing a specific notification.
      * <p>
-     * This should only be used for notifications snoozed by this listener using
-     * {@link #snoozeNotification(String, String)}. Once un-snoozed, you will get a
+     * This should only be used for notifications snoozed because of a contextual snooze suggestion
+     * you provided via {@link Adjustment#KEY_SNOOZE_CRITERIA}. Once un-snoozed, you will get a
      * {@link #onNotificationPosted(StatusBarNotification, RankingMap)} callback for the
      * notification.
      * @param key The key of the notification to snooze
-     * @hide
      */
     public final void unsnoozeNotification(String key) {
         if (!isBound()) return;
diff --git a/core/java/android/service/notification/NotificationStats.java b/core/java/android/service/notification/NotificationStats.java
index 814b4772a395a..ebfabbfda3260 100644
--- a/core/java/android/service/notification/NotificationStats.java
+++ b/core/java/android/service/notification/NotificationStats.java
@@ -16,6 +16,7 @@
 package android.service.notification;
 
 import android.annotation.IntDef;
+import android.annotation.SystemApi;
 import android.app.RemoteInput;
 import android.os.Parcel;
 import android.os.Parcelable;
@@ -98,7 +99,11 @@ public final class NotificationStats implements Parcelable {
     public NotificationStats() {
     }
 
-    private NotificationStats(Parcel in) {
+    /**
+     * @hide
+     */
+    @SystemApi
+    protected NotificationStats(Parcel in) {
         mSeen = in.readByte() != 0;
         mExpanded = in.readByte() != 0;
         mDirectReplied = in.readByte() != 0;
diff --git a/packages/ExtServices/src/android/ext/services/notification/Assistant.java b/packages/ExtServices/src/android/ext/services/notification/Assistant.java
index b6b229c770b21..9360260f319e1 100644
--- a/packages/ExtServices/src/android/ext/services/notification/Assistant.java
+++ b/packages/ExtServices/src/android/ext/services/notification/Assistant.java
@@ -220,6 +220,12 @@ public class Assistant extends NotificationAssistantService {
         out.endDocument();
     }
 
+    @Override
+    public Adjustment onNotificationEnqueued(StatusBarNotification sbn) {
+        // we use the version with channel, so this is never called.
+        return null;
+    }
+
     @Override
     public Adjustment onNotificationEnqueued(StatusBarNotification sbn,
             NotificationChannel channel) {