diff --git a/updater_sample/src/com/example/android/systemupdatersample/util/PackageFiles.java b/updater_sample/src/com/example/android/systemupdatersample/util/PackageFiles.java
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+++ b/updater_sample/src/com/example/android/systemupdatersample/util/PackageFiles.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+package com.example.android.systemupdatersample.util;
+
+/** Utility class for an OTA package. */
+public final class PackageFiles {
+
+    /**
+     * Directory used to perform updates.
+     */
+    public static final String OTA_PACKAGE_DIR = "/data/ota_package";
+
+    /**
+     * update payload, it will be passed to {@code UpdateEngine#applyPayload}.
+     */
+    public static final String PAYLOAD_BINARY_FILE_NAME = "payload.bin";
+
+    /**
+     * Currently, when calling {@code UpdateEngine#applyPayload} to perform actions
+     * that don't require network access (e.g. change slot), update_engine still
+     * talks to the server to download/verify file.
+     * {@code update_engine} might throw error when rebooting if {@code UpdateEngine#applyPayload}
+     * is not supplied right headers and tokens.
+     * This behavior might change in future android versions.
+     *
+     * To avoid extra network request in {@code update_engine}, this file has to be
+     * downloaded and put in {@code OTA_PACKAGE_DIR}.
+     */
+    public static final String PAYLOAD_METADATA_FILE_NAME = "payload_metadata.bin";
+
+    public static final String PAYLOAD_PROPERTIES_FILE_NAME = "payload_properties.txt";
+
+    /** The zip entry in an A/B OTA package, which will be used by update_verifier. */
+    public static final String CARE_MAP_FILE_NAME = "care_map.txt";
+
+    public static final String METADATA_FILE_NAME = "metadata";
+
+    /**
+     * The zip file that claims the compatibility of the update package to check against the Android
+     * framework to ensure that the package can be installed on the device.
+     */
+    public static final String COMPATIBILITY_ZIP_FILE_NAME = "compatibility.zip";
+
+    private PackageFiles() {}
+}