diff --git a/api/@ohos.application.WindowExtensionAbility.d.ts b/api/@ohos.application.WindowExtensionAbility.d.ts
new file mode 100644
index 0000000000000000000000000000000000000000..6d24e6bbdf898e4f01b0e1f876acdd2c6d0b2ad4
--- /dev/null
+++ b/api/@ohos.application.WindowExtensionAbility.d.ts
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2022-2022 Huawei Device Co., Ltd.
+ * 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.
+ */
+
+import rpc from "./@ohos.rpc";
+import ExtensionContext from "./application/ExtensionContext";
+import Want from './@ohos.application.Want';
+
+/**
+ * class of window extension ability.
+ *
+ * @since 9
+ * @syscap SystemCapability.Ability.AbilityRuntime.Core
+ * @systemapi hide for inner use.
+ * @StageModelOnly
+ */
+export default class WindowExtensionAbility {
+    /**
+     * Indicates window extension ability context.
+     *
+     * @since 9
+     * @syscap SystemCapability.Ability.AbilityRuntime.Core
+     * @systemapi hide for inner use.
+     * @StageModelOnly
+     */
+    context: ExtensionContext;
+
+    /**
+     * Called back when a window extension is first connected to an ability.
+     *
+     * @since 9
+     * @syscap SystemCapability.Ability.AbilityRuntime.Core
+     * @param want Indicates connection information about the Window ability.
+     * @systemapi hide for inner use.
+     * @return Returns the proxy of the Window ability.
+     * @StageModelOnly
+     */
+    onConnect(want: Want): rpc.RemoteObject;
+
+    /**
+     * Called back when all abilities connected to a window extension are disconnected.
+     *
+     * @since 9
+     * @syscap SystemCapability.Ability.AbilityRuntime.Core
+     * @param want Indicates disconnection information about the window extension.
+     * @systemapi hide for inner use.
+     * @return -
+     * @StageModelOnly
+     */
+    onDisconnect(want: Want): void;
+
+    /**
+     * Called back when window is created.
+     *
+     * @since 9
+     * @syscap SystemCapability.Ability.AbilityRuntime.Core
+     * @systemapi hide for inner use.
+     * @return -
+     * @StageModelOnly
+     */
+    onWindowReady(window: Window): void;
+}
+
diff --git a/api/@ohos.bundle.d.ts b/api/@ohos.bundle.d.ts
index 8a45e0a3543f847dd05525930676268e21c42158..e7ac76ed92c8703f18d78931487c9538f590fbfd 100644
--- a/api/@ohos.bundle.d.ts
+++ b/api/@ohos.bundle.d.ts
@@ -289,6 +289,12 @@ declare namespace bundle {
      * @syscap SystemCapability.BundleManager.BundleFramework
      */
     BACKUP = 9,
+    /**
+     * @default Indicates extension info with type of window
+     * @since 9
+     * @syscap SystemCapability.BundleManager.BundleFramework
+     */
+    WINDOW = 10,
     /**
      * @default Indicates extension info with type of unspecified
      * @since 9