diff --git a/framework-t/api/system-current.txt b/framework-t/api/system-current.txt
index 05cf9e8..3513573 100644
--- a/framework-t/api/system-current.txt
+++ b/framework-t/api/system-current.txt
@@ -378,11 +378,11 @@
 package android.net.nsd {
 
   public final class NsdManager {
-    method @RequiresPermission(anyOf={android.Manifest.permission.NETWORK_SETTINGS, android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, android.Manifest.permission.NETWORK_STACK}) public void registerOffloadEngine(@NonNull String, long, long, @NonNull java.util.concurrent.Executor, @NonNull android.net.nsd.OffloadEngine);
-    method @RequiresPermission(anyOf={android.Manifest.permission.NETWORK_SETTINGS, android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, android.Manifest.permission.NETWORK_STACK}) public void unregisterOffloadEngine(@NonNull android.net.nsd.OffloadEngine);
+    method @FlaggedApi("com.android.net.flags.register_nsd_offload_engine_api") @RequiresPermission(anyOf={android.Manifest.permission.NETWORK_SETTINGS, android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, android.Manifest.permission.NETWORK_STACK}) public void registerOffloadEngine(@NonNull String, long, long, @NonNull java.util.concurrent.Executor, @NonNull android.net.nsd.OffloadEngine);
+    method @FlaggedApi("com.android.net.flags.register_nsd_offload_engine_api") @RequiresPermission(anyOf={android.Manifest.permission.NETWORK_SETTINGS, android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, android.Manifest.permission.NETWORK_STACK}) public void unregisterOffloadEngine(@NonNull android.net.nsd.OffloadEngine);
   }
 
-  public interface OffloadEngine {
+  @FlaggedApi("com.android.net.flags.register_nsd_offload_engine_api") public interface OffloadEngine {
     method public void onOffloadServiceRemoved(@NonNull android.net.nsd.OffloadServiceInfo);
     method public void onOffloadServiceUpdated(@NonNull android.net.nsd.OffloadServiceInfo);
     field public static final int OFFLOAD_CAPABILITY_BYPASS_MULTICAST_LOCK = 1; // 0x1
@@ -391,7 +391,7 @@
     field public static final int OFFLOAD_TYPE_REPLY = 1; // 0x1
   }
 
-  public final class OffloadServiceInfo implements android.os.Parcelable {
+  @FlaggedApi("com.android.net.flags.register_nsd_offload_engine_api") public final class OffloadServiceInfo implements android.os.Parcelable {
     ctor public OffloadServiceInfo(@NonNull android.net.nsd.OffloadServiceInfo.Key, @NonNull java.util.List<java.lang.String>, @NonNull String, @Nullable byte[], @IntRange(from=0, to=java.lang.Integer.MAX_VALUE) int, long);
     method public int describeContents();
     method @NonNull public String getHostname();
diff --git a/framework-t/src/android/net/nsd/NsdManager.java b/framework-t/src/android/net/nsd/NsdManager.java
index ef0e34b..f59bb52 100644
--- a/framework-t/src/android/net/nsd/NsdManager.java
+++ b/framework-t/src/android/net/nsd/NsdManager.java
@@ -22,6 +22,7 @@
 import static android.net.connectivity.ConnectivityCompatChanges.ENABLE_PLATFORM_MDNS_BACKEND;
 import static android.net.connectivity.ConnectivityCompatChanges.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS_T_AND_LATER;
 
+import android.annotation.FlaggedApi;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -143,6 +144,14 @@
     private static final String TAG = NsdManager.class.getSimpleName();
     private static final boolean DBG = false;
 
+    // TODO : remove this class when udc-mainline-prod is abandoned and android.net.flags.Flags is
+    // available here
+    /** @hide */
+    public static class Flags {
+        static final String REGISTER_NSD_OFFLOAD_ENGINE_API =
+                "com.android.net.flags.register_nsd_offload_engine_api";
+    }
+
     /**
      * Broadcast intent action to indicate whether network service discovery is
      * enabled or disabled. An extra {@link #EXTRA_NSD_STATE} provides the state
@@ -365,6 +374,7 @@
      *
      * @hide
      */
+    @FlaggedApi(NsdManager.Flags.REGISTER_NSD_OFFLOAD_ENGINE_API)
     @SystemApi
     @RequiresPermission(anyOf = {NETWORK_SETTINGS, PERMISSION_MAINLINE_NETWORK_STACK,
             NETWORK_STACK})
@@ -402,6 +412,7 @@
      *
      * @hide
      */
+    @FlaggedApi(NsdManager.Flags.REGISTER_NSD_OFFLOAD_ENGINE_API)
     @SystemApi
     @RequiresPermission(anyOf = {NETWORK_SETTINGS, PERMISSION_MAINLINE_NETWORK_STACK,
             NETWORK_STACK})
diff --git a/framework-t/src/android/net/nsd/OffloadEngine.java b/framework-t/src/android/net/nsd/OffloadEngine.java
index b566b13..9015985 100644
--- a/framework-t/src/android/net/nsd/OffloadEngine.java
+++ b/framework-t/src/android/net/nsd/OffloadEngine.java
@@ -16,6 +16,7 @@
 
 package android.net.nsd;
 
+import android.annotation.FlaggedApi;
 import android.annotation.LongDef;
 import android.annotation.NonNull;
 import android.annotation.SystemApi;
@@ -33,6 +34,7 @@
  *
  * @hide
  */
+@FlaggedApi("com.android.net.flags.register_nsd_offload_engine_api")
 @SystemApi
 public interface OffloadEngine {
     /**
diff --git a/framework-t/src/android/net/nsd/OffloadServiceInfo.java b/framework-t/src/android/net/nsd/OffloadServiceInfo.java
index d5dbf19..98dc83a 100644
--- a/framework-t/src/android/net/nsd/OffloadServiceInfo.java
+++ b/framework-t/src/android/net/nsd/OffloadServiceInfo.java
@@ -16,6 +16,7 @@
 
 package android.net.nsd;
 
+import android.annotation.FlaggedApi;
 import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -39,6 +40,7 @@
  *
  * @hide
  */
+@FlaggedApi("com.android.net.flags.register_nsd_offload_engine_api")
 @SystemApi
 @RequiresApi(Build.VERSION_CODES.TIRAMISU)
 public final class OffloadServiceInfo implements Parcelable {