diff --git a/keymaster/aidl/Android.bp b/keymaster/aidl/Android.bp
index 0fb6e4c..a3800c1 100644
--- a/keymaster/aidl/Android.bp
+++ b/keymaster/aidl/Android.bp
@@ -19,9 +19,18 @@
             platform_apis: true,
         },
     },
-    versions: [
-        "1",
-        "2",
-        "3",
+    versions_with_info: [
+        {
+            version: "1",
+            imports: [],
+        },
+        {
+            version: "2",
+            imports: [],
+        },
+        {
+            version: "3",
+            imports: [],
+        },
     ],
 }
diff --git a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthToken.aidl b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthToken.aidl
index 4f21cba..6e84e98 100644
--- a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthToken.aidl
+++ b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthToken.aidl
@@ -1,14 +1,30 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 ///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
-// This file is a snapshot of an AIDL interface (or parcelable). Do not try to
-// edit this file. It looks like you are doing that because you have modified
-// an AIDL interface in a backward-incompatible way, e.g., deleting a function
-// from an interface or a field from a parcelable and it broke the build. That
-// breakage is intended.
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
 //
-// You must not make a backward incompatible changes to the AIDL files built
+// You must not make a backward incompatible change to any AIDL file built
 // with the aidl_interface module type with versions property set. The module
 // type is used to build AIDL files in a way that they can be used across
 // independently updatable components of the system. If a device is shipped
@@ -16,6 +32,7 @@
 // later when a module using the interface is updated, e.g., Mainline modules.
 
 package android.hardware.keymaster;
+/* @hide */
 @VintfStability
 parcelable HardwareAuthToken {
   long challenge;
diff --git a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthenticatorType.aidl b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthenticatorType.aidl
index 924567f..0a40549 100644
--- a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthenticatorType.aidl
+++ b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/HardwareAuthenticatorType.aidl
@@ -1,14 +1,30 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 ///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
-// This file is a snapshot of an AIDL interface (or parcelable). Do not try to
-// edit this file. It looks like you are doing that because you have modified
-// an AIDL interface in a backward-incompatible way, e.g., deleting a function
-// from an interface or a field from a parcelable and it broke the build. That
-// breakage is intended.
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
 //
-// You must not make a backward incompatible changes to the AIDL files built
+// You must not make a backward incompatible change to any AIDL file built
 // with the aidl_interface module type with versions property set. The module
 // type is used to build AIDL files in a way that they can be used across
 // independently updatable components of the system. If a device is shipped
@@ -16,6 +32,7 @@
 // later when a module using the interface is updated, e.g., Mainline modules.
 
 package android.hardware.keymaster;
+/* @hide */
 @Backing(type="int") @VintfStability
 enum HardwareAuthenticatorType {
   NONE = 0,
diff --git a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/SecurityLevel.aidl b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/SecurityLevel.aidl
index 127c1bf..d32ef68 100644
--- a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/SecurityLevel.aidl
+++ b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/SecurityLevel.aidl
@@ -1,14 +1,30 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 ///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
-// This file is a snapshot of an AIDL interface (or parcelable). Do not try to
-// edit this file. It looks like you are doing that because you have modified
-// an AIDL interface in a backward-incompatible way, e.g., deleting a function
-// from an interface or a field from a parcelable and it broke the build. That
-// breakage is intended.
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
 //
-// You must not make a backward incompatible changes to the AIDL files built
+// You must not make a backward incompatible change to any AIDL file built
 // with the aidl_interface module type with versions property set. The module
 // type is used to build AIDL files in a way that they can be used across
 // independently updatable components of the system. If a device is shipped
@@ -16,6 +32,7 @@
 // later when a module using the interface is updated, e.g., Mainline modules.
 
 package android.hardware.keymaster;
+/* @hide */
 @Backing(type="int") @VintfStability
 enum SecurityLevel {
   SOFTWARE = 0,
diff --git a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/Timestamp.aidl b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/Timestamp.aidl
index 45fa1ae..5b7b37a 100644
--- a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/Timestamp.aidl
+++ b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/Timestamp.aidl
@@ -1,14 +1,30 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 ///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
-// This file is a snapshot of an AIDL interface (or parcelable). Do not try to
-// edit this file. It looks like you are doing that because you have modified
-// an AIDL interface in a backward-incompatible way, e.g., deleting a function
-// from an interface or a field from a parcelable and it broke the build. That
-// breakage is intended.
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
 //
-// You must not make a backward incompatible changes to the AIDL files built
+// You must not make a backward incompatible change to any AIDL file built
 // with the aidl_interface module type with versions property set. The module
 // type is used to build AIDL files in a way that they can be used across
 // independently updatable components of the system. If a device is shipped
@@ -16,6 +32,7 @@
 // later when a module using the interface is updated, e.g., Mainline modules.
 
 package android.hardware.keymaster;
+/* @hide */
 @VintfStability
 parcelable Timestamp {
   long milliSeconds;
diff --git a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/VerificationToken.aidl b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/VerificationToken.aidl
index b116dac..10fa5e1 100644
--- a/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/VerificationToken.aidl
+++ b/keymaster/aidl/aidl_api/android.hardware.keymaster/current/android/hardware/keymaster/VerificationToken.aidl
@@ -1,14 +1,30 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 ///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
-// This file is a snapshot of an AIDL interface (or parcelable). Do not try to
-// edit this file. It looks like you are doing that because you have modified
-// an AIDL interface in a backward-incompatible way, e.g., deleting a function
-// from an interface or a field from a parcelable and it broke the build. That
-// breakage is intended.
+// This file is a snapshot of an AIDL file. Do not edit it manually. There are
+// two cases:
+// 1). this is a frozen version file - do not edit this in any case.
+// 2). this is a 'current' file. If you make a backwards compatible change to
+//     the interface (from the latest frozen version), the build system will
+//     prompt you to update this file with `m <name>-update-api`.
 //
-// You must not make a backward incompatible changes to the AIDL files built
+// You must not make a backward incompatible change to any AIDL file built
 // with the aidl_interface module type with versions property set. The module
 // type is used to build AIDL files in a way that they can be used across
 // independently updatable components of the system. If a device is shipped
@@ -16,6 +32,7 @@
 // later when a module using the interface is updated, e.g., Mainline modules.
 
 package android.hardware.keymaster;
+/* @hide */
 @VintfStability
 parcelable VerificationToken {
   long challenge;
diff --git a/keymaster/aidl/android/hardware/keymaster/HardwareAuthToken.aidl b/keymaster/aidl/android/hardware/keymaster/HardwareAuthToken.aidl
index 99b036a..427c192 100644
--- a/keymaster/aidl/android/hardware/keymaster/HardwareAuthToken.aidl
+++ b/keymaster/aidl/android/hardware/keymaster/HardwareAuthToken.aidl
@@ -16,8 +16,8 @@
 
 package android.hardware.keymaster;
 
-import android.hardware.keymaster.Timestamp;
 import android.hardware.keymaster.HardwareAuthenticatorType;
+import android.hardware.keymaster.Timestamp;
 
 /**
  * HardwareAuthToken is used to prove successful user authentication, to unlock the use of a key.
@@ -27,10 +27,10 @@
  * begin(), update(), and finish() to prove that authentication occurred.  See those methods for
  * more details.  It is up to the caller to determine which of the generated auth tokens is
  * appropriate for a given key operation.
+ * @hide
  */
 @VintfStability
 parcelable HardwareAuthToken {
-
     /**
      * challenge is a value that's used to enable authentication tokens to authorize specific
      * events.  The primary use case for challenge is to authorize an IKeymasterDevice cryptographic
@@ -49,7 +49,7 @@
      *  but is created in an authentication application in the secure environment, such as the
      *  Fingerprint application.
      */
-    long authenticatorId;  // Secure authenticator ID.
+    long authenticatorId; // Secure authenticator ID.
 
     /**
      * authenticatorType describes the type of authentication that took place, e.g. password or
diff --git a/keymaster/aidl/android/hardware/keymaster/HardwareAuthenticatorType.aidl b/keymaster/aidl/android/hardware/keymaster/HardwareAuthenticatorType.aidl
index 3141858..7a303a7 100644
--- a/keymaster/aidl/android/hardware/keymaster/HardwareAuthenticatorType.aidl
+++ b/keymaster/aidl/android/hardware/keymaster/HardwareAuthenticatorType.aidl
@@ -20,6 +20,7 @@
  * Hardware authentication type, used by HardwareAuthTokens to specify the mechanism used to
  * authentiate the user, and in KeyCharacteristics to specify the allowable mechanisms for
  * authenticating to activate a key.
+ * @hide
  */
 @VintfStability
 @Backing(type="int")
diff --git a/keymaster/aidl/android/hardware/keymaster/SecurityLevel.aidl b/keymaster/aidl/android/hardware/keymaster/SecurityLevel.aidl
index 00578a4..0b84392 100644
--- a/keymaster/aidl/android/hardware/keymaster/SecurityLevel.aidl
+++ b/keymaster/aidl/android/hardware/keymaster/SecurityLevel.aidl
@@ -18,6 +18,7 @@
 
 /**
  * Device security levels.
+ * @hide
  */
 @VintfStability
 @Backing(type="int")
diff --git a/keymaster/aidl/android/hardware/keymaster/Timestamp.aidl b/keymaster/aidl/android/hardware/keymaster/Timestamp.aidl
index 19ea944..0b0c36f 100644
--- a/keymaster/aidl/android/hardware/keymaster/Timestamp.aidl
+++ b/keymaster/aidl/android/hardware/keymaster/Timestamp.aidl
@@ -16,14 +16,13 @@
 
 package android.hardware.keymaster;
 
-
 /**
  * Time in milliseconds since some arbitrary point in time.  Time must be monotonically increasing,
  * and a secure environment's notion of "current time" must not repeat until the Android device
  * reboots, or until at least 50 million years have elapsed (note that this requirement is satisfied
  * by setting the clock to zero during each boot, and then counting time accurately).
+ * @hide
  */
-
 @VintfStability
 parcelable Timestamp {
     long milliSeconds;
diff --git a/keymaster/aidl/android/hardware/keymaster/VerificationToken.aidl b/keymaster/aidl/android/hardware/keymaster/VerificationToken.aidl
index 5efd937..ceee941 100644
--- a/keymaster/aidl/android/hardware/keymaster/VerificationToken.aidl
+++ b/keymaster/aidl/android/hardware/keymaster/VerificationToken.aidl
@@ -24,6 +24,7 @@
  *
  * This version of the parcelable currently don't use the parametersVerified field since it's not
  * needed for time-based verification. This can be added in a later version, if needed.
+ * @hide
  */
 @VintfStability
 parcelable VerificationToken {
@@ -39,7 +40,6 @@
      */
     Timestamp timestamp;
 
-
     /**
      * SecurityLevel of the secure environment that generated the token.
      */