diff --git a/api/@ohos.arkui.stateManagement.d.ets b/api/@ohos.arkui.stateManagement.d.ets
index c269289b2733c9ef791b3eb713c64870deb6b2da..1684309c30a8baf402993826d48e7da68f929eaf 100644
--- a/api/@ohos.arkui.stateManagement.d.ets
+++ b/api/@ohos.arkui.stateManagement.d.ets
@@ -23,4 +23,5 @@ export * from './arkui/stateManagement/decorator';
 export * from './arkui/stateManagement/runtime';
 export * from './arkui/stateManagement/storage/appStorage';
 export * from './arkui/stateManagement/storage/localStorage';
-export * from './arkui/stateManagement/utils';
\ No newline at end of file
+export * from './arkui/stateManagement/utils';
+export * from './arkui/stateManagement/storage/storageProperty';
\ No newline at end of file
diff --git a/api/arkui/stateManagement/decorator.d.ets b/api/arkui/stateManagement/decorator.d.ets
index a626dc9e896980b020b846331d9af5753900d666..3c3659fd93a08ca3d2ab31336a0e0fe894711ea5 100644
--- a/api/arkui/stateManagement/decorator.d.ets
+++ b/api/arkui/stateManagement/decorator.d.ets
@@ -77,58 +77,238 @@ export declare @interface Watch {
 @Retention({policy: "SOURCE"})
 export declare @interface Require {};
 
+/**
+ * Define decorated variable interface.
+ *
+ * @interface IDecoratedVariable
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
 export declare interface IDecoratedVariable {
-    readonly varName: string;
+  /**
+   * Decorated variable name.
+   *
+   * @type { string }
+   * @readonly
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  readonly varName: string;
 }
 
+/**
+ * Define V1 decorated variable interface.
+ *
+ * @extends IDecoratedVariable
+ * @interface IDecoratedVariable
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
 export declare interface IDecoratedV1Variable<T> extends IDecoratedVariable {
-    registerWatchToSource(me: IDecoratedV1Variable<T>): void;
+  /**
+   * Registers the watch callback function with the data source.
+   *
+   * @param { IDecoratedV1Variable<T> } decoratedVar
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  registerWatchToSource(decoratedVar: IDecoratedV1Variable<T>): void;
 }
 
+/**
+ * Define decorated immutable variable interface.
+ *
+ * @interface IDecoratedImmutableVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
 export declare interface IDecoratedImmutableVariable<T> {
-    get(): T;
+  /**
+   * Get the state variable.
+   *
+   * @returns { T }
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  get(): T;
 }
 
+/**
+ * Define decorated mutable variable interface.
+ *
+ * @interface IDecoratedMutableVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
 export declare interface IDecoratedMutableVariable<T> {
-    get(): T;
-    set(newValue: T): void;
+  /**
+   * Get the state variable.
+   *
+   * @returns { T }
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  get(): T;
+  /**
+   * Set the state variable with a new Value.
+   *
+   * @param { T } newValue
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  set(newValue: T): void;
 }
 
+/**
+ * Define decorated updatable variable interface.
+ *
+ * @interface IDecoratedUpdatableVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
 export declare interface IDecoratedUpdatableVariable<T> {
-    update(newValue: T): void;
+  /**
+   * Update the state variable with a new Value.
+   *
+   * @param { T } newValue
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  update(newValue: T): void;
 }
 
-export declare interface IStateDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {
-}
+/**
+ * Define state decoration variable interface.
+ *
+ * @extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T>
+ * @interface IStateDecoratedVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export declare interface IStateDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {}
 
 export declare interface IPropDecoratedVariable<T> extends IDecoratedMutableVariable<T>,
     IDecoratedUpdatableVariable<T>, IDecoratedV1Variable<T> {
 }
 
-export declare interface ILinkDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {
-}
+/**
+ * Define Link decoration variable interface.
+ *
+ * @extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T>
+ * @interface ILinkDecoratedVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export declare interface ILinkDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {}
 
-export declare interface IProvideDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {
-}
+/**
+ * Define Provide decoration variable interface.
+ *
+ * @extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T>
+ * @interface IProvideDecoratedVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export declare interface IProvideDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {}
 
-export declare interface IConsumeDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {
-}
+/**
+ * Define Consume decoration variable interface.
+ *
+ * @extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T>
+ * @interface IConsumeDecoratedVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export declare interface IConsumeDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {}
 
+/**
+ * Define ObjectLink decoration variable interface.
+ *
+ * @extends IDecoratedImmutableVariable<T>, IDecoratedUpdatableVariable<T>, IDecoratedV1Variable<T>
+ * @interface IObjectLinkDecoratedVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
 export declare interface IObjectLinkDecoratedVariable<T> extends IDecoratedImmutableVariable<T>,
-    IDecoratedUpdatableVariable<T>, IDecoratedV1Variable<T> {
-}
+    IDecoratedUpdatableVariable<T>, IDecoratedV1Variable<T> {}
 
-export declare interface IStorageLinkDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {
-}
+/**
+ * Define StorageLink decoration variable interface.
+ *
+ * @extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T>
+ * @interface IStorageLinkDecoratedVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export declare interface IStorageLinkDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {}
 
+/**
+ * Define StorageProp decoration variable interface.
+ *
+ * @extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T>
+ * @interface IStoragePropDecoratedVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
 export declare interface IStoragePropDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {
 }
 
-export type LinkSourceType<T> = IDecoratedV1Variable<T>;
+/**
+ * Define StoragePropRef decoration variable interface.
+ *
+ * @extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T>
+ * @interface IStoragePropRefDecoratedVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export declare interface IStoragePropRefDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {}
+
+/**
+ * Define LocalStorageLink decoration variable interface.
+ *
+ * @extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T>
+ * @interface ILocalStorageLinkDecoratedVariable<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export declare interface ILocalStorageLinkDecoratedVariable<T> extends IDecoratedMutableVariable<T>, IDecoratedV1Variable<T> {}
+
+/**
+ * Define Link source type.
+ *
+ * @typedef { IStateDecoratedVariable<T> | ILinkDecoratedVariable<T> | IObjectLinkDecoratedVariable<T> |
+    IPropDecoratedVariable<T> | IStorageLinkDecoratedVariable<T> | ILocalStorageLinkDecoratedVariable<T> | IStoragePropRefDecoratedVariable<T> |
+    IProvideDecoratedVariable<T> | IConsumeDecoratedVariable<T> } LinkSourceType<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export type LinkSourceType<T> = IStateDecoratedVariable<T> | ILinkDecoratedVariable<T> | IObjectLinkDecoratedVariable<T> |
+    IPropDecoratedVariable<T> | IStorageLinkDecoratedVariable<T> | ILocalStorageLinkDecoratedVariable<T> | IStoragePropRefDecoratedVariable<T> |
+    IProvideDecoratedVariable<T> | IConsumeDecoratedVariable<T>;
 
+
+/**
+ * Define mutable state meta interface.
+ *
+ * @interface IMutableStateMeta
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
 export declare interface IMutableStateMeta {
-    addRef(): void;
-    fireChange(): void;
+  /**
+   * Collect the dependancy for UI component with state variable
+   *
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  addRef(): void;
+  /**
+   * Notify UI component to update when state variable is changed
+   *
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  fireChange(): void;
 }
 
 export declare interface IMutableKeyedStateMeta {
@@ -169,10 +349,53 @@ export declare interface IStateMgmtFactory {
         provideAlias: string, watchFunc?: WatchFuncType): IConsumeDecoratedVariable<T>;
     makeObjectLink<T>(owningView: ExtendableComponent, varName: string,
         initValue: T, wathcFunc?: WatchFuncType): IObjectLinkDecoratedVariable<T>;
+
+  /**
+   * Create a StorageLink variable instance.
+   *
+   * @param { ExtendableComponent } owningView - custom component.
+   * @param { string } propName - property name.
+   * @param { string } varName - state variable name.
+   * @param { T } initValue - init value.
+   * @param { Type } ttype - value type.
+   * @param { WatchFuncType } [watchFunc] - watch type
+   * @returns { IStorageLinkDecoratedVariable<T> } StorageLink instance
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
     makeStorageLink<T>(owningView: ExtendableComponent, propName: string,
-        varName: string, initValue: T, watchFunc?: WatchFuncType): IStorageLinkDecoratedVariable<T>;
-    makeStorageProp<T>(owningView: ExtendableComponent, propName: string,
-        varName: string, initValue: T, watchFunc?: WatchFuncType): IStoragePropDecoratedVariable<T>;
+        varName: string, initValue: T, ttype: Type, watchFunc?: WatchFuncType): IStorageLinkDecoratedVariable<T>;
+   /**
+    * Create a StoragePropRef variable instance.
+    *
+    * @param { ExtendableComponent } owningView - custom component.
+    * @param { string } propName - property name.
+    * @param { string } varName - state variable name.
+    * @param { T } initValue - init value.
+    * @param { Type } ttype - value type.
+    * @param { WatchFuncType } [watchFunc] - watch type
+    * @returns { IStoragePropRefDecoratedVariable<T> } StoragePropRef instance
+    * @syscap SystemCapability.ArkUI.ArkUI.Full
+    * @since 20
+    */
+    makeStoragePropRef<T>(owningView: ExtendableComponent, propName: string,
+        varName: string, initValue: T, ttype: Type, watchFunc?: WatchFuncType): IStoragePropRefDecoratedVariable<T>;
+
+  /**
+   * Create a LocalStorageLink variable instance.
+   *
+   * @param { ExtendableComponent } owningView - custom component.
+   * @param { string } propName - property name.
+   * @param { string } varName - state variable name.
+   * @param { T } initValue - init value.
+   * @param { Type } ttype - value type
+   * @param { WatchFuncType } [watchFunc] - watch type
+   * @returns { ILocalStorageLinkDecoratedVariable<T> } LocalStorageLink instance
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+    makeLocalStorageLink<T>(owningView: ExtendableComponent, propName: string,
+        varName: string, initValue: T, ttype: Type, watchFunc?: WatchFuncType): ILocalStorageLinkDecoratedVariable<T>;
 }
 
 export type WatchFuncType = ((propertyName: string) => void);
diff --git a/api/arkui/stateManagement/storage/appStorage.d.ets b/api/arkui/stateManagement/storage/appStorage.d.ets
index bf94b5e0e98c4d4492b6b57fbddf325505c19c24..4a3bf1b8ff53ca02c74ed1d69168e00fa44b1923 100644
--- a/api/arkui/stateManagement/storage/appStorage.d.ets
+++ b/api/arkui/stateManagement/storage/appStorage.d.ets
@@ -19,21 +19,5 @@
  */
 
 import { LocalStorage } from './localStorage';
-import { AbstractProperty, SubscribedAbstractProperty } from '../decorator';
 
-export declare class AppStorage extends LocalStorage {
-    public static ref<T>(propName: string): AbstractProperty<T> | undefined;
-    public static setAndRef<T>(propName: string, defaultValue: T): AbstractProperty<T>;
-    public static link<T>(propName: string): SubscribedAbstractProperty<T> | undefined;
-    public static setAndLink<T>(propName: string, defaultValue: T): SubscribedAbstractProperty<T>;
-    public static prop<T>(propName: string): SubscribedAbstractProperty<T> | undefined;
-    public static setAndProp<T>(propName: string, defaultValue: T): SubscribedAbstractProperty<T>;
-    public static has(propName: string): boolean;
-    public static get<T>(propName: string): T | undefined;
-    public static set<T>(propName: string, newValue: T): boolean;
-    public static setOrCreate<T>(propName: string, newValue: T): void;
-    public static keys(): IterableIterator<string>;
-    public static size(): number;
-    public static delete(propName: string): boolean;
-    public static clear(): boolean;
-}
\ No newline at end of file
+export const AppStorage: LocalStorage = new LocalStorage();
diff --git a/api/arkui/stateManagement/storage/localStorage.d.ets b/api/arkui/stateManagement/storage/localStorage.d.ets
index 4b9a33bab94141a71c2545f7d719d42c686dc2cf..4ddea45ee6a853c58ea43f43a4e65b7a441c6be1 100644
--- a/api/arkui/stateManagement/storage/localStorage.d.ets
+++ b/api/arkui/stateManagement/storage/localStorage.d.ets
@@ -18,23 +18,180 @@
  * @arkts 1.2
  */
 
-import { AbstractProperty, SubscribedAbstractProperty } from '../decorator';
+import { IStorageProperties, AbstractProperty, SubscribedAbstractProperty } from './storageProperty';
 
+/**
+ * LocalStorage
+ * Class implements a Map of ObservableObjectBase UI state variables.
+ * Instances can be created to manage UI state within a limited "local"
+ * access, and life cycle as defined by the app.
+ * AppStorage singleton is sub-class of LocalStorage for
+ * UI state of app-wide access and same life cycle as the app.
+ *
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
 export declare class LocalStorage {
-    public constructor(initializingProperties?: Object);
-    public static getShared(): LocalStorage | undefined;
-    public ref<T>(propName: string): AbstractProperty<T> | undefined;
-    public setAndRef<T>(propName: string, defaultValue: T): AbstractProperty<T>;
-    public link<T>(propName: string): SubscribedAbstractProperty<T> | undefined;
-    public setAndLink<T>(propName: string, defaultValue: T): SubscribedAbstractProperty<T>;
-    public prop<T>(propName: string): SubscribedAbstractProperty<T> | undefined;
-    public setAndProp<T>(propName: string, defaultValue: T): SubscribedAbstractProperty<T>;
-    public has(propName: string): boolean;
-    public get<T>(propName: string): T | undefined;
-    public set<T>(propName: string, newValue: T): boolean;
-    public setOrCreate<T>(propName: string, newValue: T): boolean;
-    public keys(): IterableIterator<string>;
-    public size(): number;
-    public delete(propName: string): boolean;
-    public clear(): boolean;
+  /**
+   * Construct new instance of LocalStorage
+   * initialize with all properties and their values that Object.keys(params) returns
+   * Property values must not be undefined.
+   *
+   * @param { Record<string, IStorageProperties> } [initializingProperties] - Record<string, IStorageProperties> 
+   * containing keys and values. 
+   * see set() for valid values
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public constructor(initializingProperties?: Record<string, IStorageProperties>);
+  /**
+   * Obtain a handler or an alias to LocalStorage property with given name.
+   *
+   * @param { string } propName LocalStorage property name
+   * @param {Type} ttype - data type
+   * @returns { AbstractProperty<T> | undefined } AbstractProperty object if property with given name exists
+   * return undefined otherwise.
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public ref<T>(propName: string, ttype: Type): AbstractProperty<T> | undefined;
+  /**
+   * Obtain a handler or an alias to LocalStorage property with given name.
+   *
+   * If property does not exist in LocalStorage, create it with given default value.
+   *
+   * @param { string } propName LocalStorage property name
+   * @param { T } defaultValue If property does not exist in LocalStorage,
+   *        create it with given default value.
+   * @param {Type} ttype - data type
+   * @returns { AbstractProperty<T> } AbstractProperty object
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public setAndRef<T>(propName: string, defaultValue: T, ttype: Type): AbstractProperty<T>;
+  /**
+   * Create and return a two-way sync "(link") to named property
+   *
+   * @param { string } propName - name of source property in LocalStorage
+   * @param { Type } ttype - data type
+   * @returns { SubscribedAbstractProperty<T> | undefined } instance of  SubscribedAbstractProperty<T>
+   *           return undefined if named property does not already exist in LocalStorage
+   *           Apps can use SDK functions of base class SubscribedPropertyAbstract<T>
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @crossplatform
+   * @since 20
+   */
+  public link<T>(propName: string, ttype: Type): SubscribedAbstractProperty<T> | undefined;
+
+  /**
+   * Like see link(), but will create and initialize a new source property in LocalStorage if missing
+   *
+   * @param { string } propName - name of source property in LocalStorage
+   * @param { T } defaultValue - value to be used for initializing new property in LocalStorage
+   *        default value must be of type T, can be undefined or null.
+   * @param { Type } ttype - data type
+   * @returns { SubscribedAbstractProperty<T> } instance of  SubscribedAbstractProperty<T>
+   *          Apps can use SDK functions of base class SubscribedAbstractProperty<T>
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public setAndLink<T>(propName: string, defaultValue: T, ttype: Type): SubscribedAbstractProperty<T>;
+
+  /**
+   * Check if LocalStorage has a property with given name
+   * return true if property with given name exists
+   * same as ES6 Map.prototype.has()
+   *
+   * @param { string } propName - searched property
+   * @param { Type } [ttype] - data type
+   * @returns { boolean } true if property with such name exists in LocalStorage
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public has(propName: string, ttype?: Type): boolean;
+  /**
+   * Returns value of given property
+   * return undefined if no property with this name
+   *
+   * @param { string } propName - property name
+   * @param {Type} ttype - data type
+   * @returns { T | undefined } property value if found or undefined
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public get<T>(propName: string, ttype: Type): T | undefined;
+  /**
+   * Set value of given property in LocalStorage
+   * Method sets nothing and returns false if property with this name does not exist in LocalStorage
+   * newValue can be undefined or null from API 20.
+   *
+   * @param { string } propName
+   * @param { T } newValue - must be of type T, can be undefined or null
+   * @returns { boolean } true on success, i.e. when above conditions are satisfied, otherwise false
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public set<T>(propName: string, newValue: T): boolean;
+  /**
+   * Set value of given property, if it exists, see set() .
+   * Add property if no property with given name and initialize with given value.
+   * newValue can be undefined or null from API 12
+   *
+   * @param { string } propName
+   * @param { T } newValue - must be of type T, can be undefined or null
+   * @param { Type } ttype - data type
+   * @returns { boolean } true on success, i.e. when above conditions are satisfied, otherwise false
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public setOrCreate<T>(propName: string, newValue: T, ttype: Type): boolean;
+  /**
+   * Provide names of all properties in LocalStorage
+   * same as ES6 Map.prototype.keys()
+   *
+   * @returns { IterableIterator<string> } return a Map Iterator
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public keys(): IterableIterator<string>;
+  /**
+   * Returns number of properties in LocalStorage
+   * same as Map.prototype.size()
+   *
+   * @returns { number } return number of properties
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public size(): number;
+  /**
+   * Delete property from StorageBase
+   * Use with caution:
+   * Before deleting a prop from LocalStorage all its subscribers need to
+   * unsubscribe from the property.
+   * This method fails and returns false if given property still has subscribers
+   * Another reason for failing is unknown property.
+   * Developer advise:
+   * Subscribers are created with see link(), see prop()
+   * and also via @LocalStorageLink and @LocalStorageProp state variable decorators.
+   * That means as long as their is a @Component instance that uses such decorated variable
+   * or a sync relationship with a SubscribedAbstractProperty variable the property can nit
+   * (and also should not!) be deleted from LocalStorage.
+   *
+   * @param { string } propName
+   * @returns { boolean } false if method failed
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public delete(propName: string): boolean;
+  /**
+   * Delete all properties from the LocalStorage instance
+   * Precondition is that there are no subscribers.
+   * method returns false and deletes no properties if there is any property
+   * that still has subscribers
+   *
+   * @returns { boolean }
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  public clear(): boolean;
 }
\ No newline at end of file
diff --git a/api/arkui/stateManagement/storage/storageProperty.d.ets b/api/arkui/stateManagement/storage/storageProperty.d.ets
new file mode 100644
index 0000000000000000000000000000000000000000..191374a7e22d6df9a5e8b2507bed8f5d68382f05
--- /dev/null
+++ b/api/arkui/stateManagement/storage/storageProperty.d.ets
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2025 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.
+ */
+/**
+ * @file
+ * @kit ArkUI
+ * @arkts 1.2
+ */
+
+/**
+ * Defines the callback that is called when state variable with value is change
+ * @typedef { function } OnChangeType
+ * @param {string} propertyName - property name
+ * @param {T} newValue - the new value of state variable
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export type OnChangeType<T> = (propertyName: string, newValue: T) => void;
+
+/**
+ * Define AbstractProperty<T> interface.
+ *
+ *  AbstractProperty can be understood as a handler or an alias
+ *  to a property inside LocalStorage / AppStorage singleton
+ *  allows to read the value with @see get and to change the
+ *  value with @see set.
+ *
+ * @interface AbstractProperty<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export interface AbstractProperty<T> {
+  /**
+   * Returns the name of the referenced property
+   *
+   * @returns { string } name of the referenced property
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+   info(): string { return ""; };
+  
+  /**
+   * Returns the type of the referenced property
+   *
+   * @returns { Type } type of the referenced property
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+   ttype(): Type { return Type.of(undefined); };
+
+  /**
+   * Reads value of the referenced AppStorage/LocalStorage property.
+   *
+   * @returns { T } value of the referenced AppStorage/LocalStorage property.
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+   get(): T { return undefined; };
+
+  /**
+   * Assign a new value to the referenced property
+   *
+   * @param {T} newValue - a new value of the referenced property
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+   set(newValue: T): void {};
+  /**
+   * Register callback function to be called on value change of the referenced property
+   * calling with value undefined clear the callback.
+   *
+   * @param {OnChangeType<T> | undefined} onChangeFunc - register callback function
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+   onChange(onChangeFunc: OnChangeType<T> | undefined): void {};
+}
+
+/**
+ *   SubscribedAbstractProperty<T> is the return value of
+ *   - AppStorage static functions Link(), Prop(), SetAndLink(), and SetAndProp()
+ *   - LocalStorage member methods link(), prop(), setAndLink(), and setAndProp()
+ *   'T' can be boolean, string, number or custom class.
+ * Main functions
+ *   see get() reads the linked AppStorage/LocalStorage property value,
+ *   see set(newValue) write a new value to the synched AppStorage/LocalStorage property
+ *   see aboutToBeDeleted() ends the sync relationship with the AppStorage/LocalStorage property
+ *        The app must call this function before the SubscribedAbstractProperty<T> object
+ *        goes out of scope.
+ *
+ * @extends AbstractProperty<T>
+ * @interface SubscribedAbstractProperty<T>
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export interface SubscribedAbstractProperty<T> extends AbstractProperty<T> {
+  /**
+   * An app needs to call this function before the instance of SubscribedAbstractProperty
+   * goes out of scope / is subject to garbage collection. Its purpose is to unregister the
+   * variable from the two-way/one-way sync relationship that AppStorage/LocalStorage.link()/prop()
+   * and related functions create.
+   *
+   * @syscap SystemCapability.ArkUI.ArkUI.Full
+   * @since 20
+   */
+  aboutToBeDeleted(): void {};
+}
+
+/**
+ * Define IStorageProperties interface
+ *
+ * @interface IStorageProperties
+ * @syscap SystemCapability.ArkUI.ArkUI.Full
+ * @since 20
+ */
+export interface IStorageProperties {
+ /**
+  * Storage value.
+  *
+  * @type { NullishType }
+  * @syscap SystemCapability.ArkUI.ArkUI.Full
+  * @since 20
+  */
+  value: NullishType;
+ /**
+  * Storage variable ttype.
+  *
+  * @type { Type }
+  * @syscap SystemCapability.ArkUI.ArkUI.Full
+  * @since 20
+  */
+  ttype: Type;
+}
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