# @ohos.app.ability.UIExtensionContentSession (UI Operation Class for ExtensionAbilities with UI)

**UIExtensionContentSession** is an instance created when the [UIExtensionAbility](js-apis-app-ability-uiExtensionAbility.md) loads UI content. When the UIExtensionComponent starts a UIExtensionAbility, the UIExtensionAbility creates a UIExtensionContentSession instance and returns it through the [onSessionCreate](js-apis-app-ability-uiExtensionAbility.md#uiextensionabilityonsessioncreate) callback. One UIExtensionComponent corresponds to one **UIExtensionContentSession** instance, which provides methods such as UI loading and result notification. The **UIExtensionContentSession** instances of multiple UIExtensionAbilities are operated separately.

> **NOTE**
> 
> The initial APIs of this module are supported since API version 10. Newly added APIs will be marked with a superscript to indicate their earliest API version. 
> The APIs of this module can be used only in the stage model.

## Modules to Import

```ts
import UIExtensionContentSession from '@ohos.app.ability.UIExtensionContentSession';
```

## UIExtensionContentSession.sendData

sendData(data: Record\<string, Object>): void

Sends data to the UIExtensionComponent.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| data | Record\<string,&nbsp;Object> | Yes| Data to send.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000050 | Internal error. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.setReceiveDataCallback

setReceiveDataCallback(callback: (data: Record\<string, Object>) => void): void

Sets a callback to receive data from the UIExtensionComponent.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| callback | (data: Record\<string, Object>) => void | Yes| Callback used to receive data.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000050 | Internal error. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.setReceiveDataForResultCallback<sup>11+</sup>

setReceiveDataForResultCallback(callback: (data: { [key: string]: Object }) => { [key: string]: Object }): void

Sets a callback with a return value to receive data from the UIExtensionComponent.

**System API**: This is a system API.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core


**Parameters**

| Name| Type| Mandatory| Description            |
| -------- | -------- | -------- |----------------|
| callback | (data: { [key: string]: Object }) => { [key: string]: Object } | Yes| Callback with a return value used to receive data.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000050 | Internal error. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.loadContent

loadContent(path: string, storage?: LocalStorage): void;

Loads content from a page associated with a local storage to the window corresponding to the current UIExtensionComponent.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name | Type                                           | Mandatory| Description                                                        |
| ------- | ----------------------------------------------- | ---- | ------------------------------------------------------------ |
| path    | string                                          | Yes  | Path of the page from which the content will be loaded.                                        |
| storage | [LocalStorage](../../quick-start/arkts-localstorage.md) | No  | A storage unit, which provides storage for variable state properties and non-variable state properties of an application. This parameter is left blank by default.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000050 | Internal error. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.startAbility

startAbility(want: Want, callback: AsyncCallback&lt;void&gt;): void;

Starts an ability. This API uses an asynchronous callback to return the result.

Observe the following when using this API:
 - The application where the UIExtensionComponent is located must be running in the foreground and gain focus.
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **exported** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-app-ability-want.md) | Yes| Want information about the target ability.|
| callback | AsyncCallback&lt;void&gt; | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000001 | The specified ability does not exist. |
| 16000002 | Incorrect ability type. |
| 16000004 | Can not start invisible component. |
| 16000005 | The specified process does not have the permission. |
| 16000006 | Cross-user operations are not allowed. |
| 16000008 | The crowdtesting application expires. |
| 16000009 | An ability cannot be started or stopped in Wukong mode. |
| 16000010 | The call with the continuation flag is forbidden.        |
| 16000011 | The context does not exist.        |
| 16000012 | The application is controlled.        |
| 16000013 | The application is controlled by EDM.       |
| 16000050 | Internal error. |
| 16000053 | The ability is not on the top of the UI. |
| 16000055 | Installation-free timed out. |
| 16200001 | The caller has been released. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.startAbility

startAbility(want: Want, options: StartOptions, callback: AsyncCallback&lt;void&gt;): void;

Starts an ability with **options** specified. This API uses an asynchronous callback to return the result.

Observe the following when using this API:
 - The application where the UIExtensionComponent is located must be running in the foreground and gain focus.
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **exported** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-app-ability-want.md)  | Yes| Want information about the target ability.|
| options | [StartOptions](js-apis-app-ability-startOptions.md) | Yes| Parameters used for starting the ability.|
| callback | AsyncCallback&lt;void&gt; | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000001 | The specified ability does not exist. |
| 16000004 | Can not start invisible component. |
| 16000005 | The specified process does not have the permission. |
| 16000006 | Cross-user operations are not allowed. |
| 16000008 | The crowdtesting application expires. |
| 16000009 | An ability cannot be started or stopped in Wukong mode. |
| 16000011 | The context does not exist.        |
| 16000012 | The application is controlled.        |
| 16000013 | The application is controlled by EDM.       |
| 16000050 | Internal error. |
| 16000053 | The ability is not on the top of the UI. |
| 16000055 | Installation-free timed out. |
| 16200001 | The caller has been released. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.startAbility

startAbility(want: Want, options?: StartOptions): Promise&lt;void&gt;;

Starts an ability. This API uses a promise to return the result.

Observe the following when using this API:
 - The application where the UIExtensionComponent is located must be running in the foreground and gain focus.
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **exported** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-app-ability-want.md) | Yes| Want information about the target ability.|
| options | [StartOptions](js-apis-app-ability-startOptions.md) | No| Parameters used for starting the ability.|

**Return value**

| Type| Description|
| -------- | -------- |
| Promise&lt;void&gt; | Promise used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000001 | The specified ability does not exist. |
| 16000002 | Incorrect ability type. |
| 16000004 | Can not start invisible component. |
| 16000005 | The specified process does not have the permission. |
| 16000006 | Cross-user operations are not allowed. |
| 16000008 | The crowdtesting application expires. |
| 16000009 | An ability cannot be started or stopped in Wukong mode. |
| 16000010 | The call with the continuation flag is forbidden.        |
| 16000011 | The context does not exist.        |
| 16000012 | The application is controlled.        |
| 16000013 | The application is controlled by EDM.       |
| 16000050 | Internal error. |
| 16000053 | The ability is not on the top of the UI. |
| 16000055 | Installation-free timed out. |
| 16200001 | The caller has been released. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.startAbilityForResult

startAbilityForResult(want: Want, callback: AsyncCallback&lt;AbilityResult&gt;): void;

Starts an ability. This API uses an asynchronous callback to return the result to the caller after the ability is terminated. An ability can be terminated in the following ways:
 - Normally, you can call [terminateSelfWithResult](js-apis-inner-application-uiAbilityContext.md#uiabilitycontextterminateselfwithresult) to terminate the ability. The result is returned to the caller.
 - If an exception occurs, for example, the ability is killed, an error message, in which **resultCode** is **-1**, is returned to the caller.
 - If different applications call this API to start an ability that uses the singleton mode and then call [terminateSelfWithResult](js-apis-inner-application-uiAbilityContext.md#uiabilitycontextterminateselfwithresult) to terminate the ability, the normal result is returned to the last caller, and an exception message, in which **resultCode** is **-1**, is returned to others.

Observe the following when using this API:
 - The application where the UIExtensionComponent is located must be running in the foreground and gain focus.
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **exported** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want |[Want](js-apis-app-ability-want.md) | Yes| Want information about the target ability.|
| callback | AsyncCallback&lt;[AbilityResult](js-apis-inner-ability-abilityResult.md)&gt; | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000001 | The specified ability does not exist. |
| 16000002 | Incorrect ability type. |
| 16000004 | Can not start invisible component. |
| 16000005 | The specified process does not have the permission. |
| 16000006 | Cross-user operations are not allowed. |
| 16000008 | The crowdtesting application expires. |
| 16000009 | An ability cannot be started or stopped in Wukong mode. |
| 16000010 | The call with the continuation flag is forbidden. |
| 16000011 | The context does not exist. |
| 16000012 | The application is controlled.        |
| 16000013 | The application is controlled by EDM.       |
| 16000050 | Internal error. |
| 16000053 | The ability is not on the top of the UI. |
| 16000055 | Installation-free timed out. |
| 16200001 | The caller has been released. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.startAbilityForResult

startAbilityForResult(want: Want, options: StartOptions, callback: AsyncCallback&lt;AbilityResult&gt;): void;

Starts an ability with **options** specified. This API uses an asynchronous callback to return the result to the caller after the ability is terminated. An ability can be terminated in the following ways:
 - Normally, you can call [terminateSelfWithResult](js-apis-inner-application-uiAbilityContext.md#uiabilitycontextterminateselfwithresult) to terminate the ability. The result is returned to the caller.
 - If an exception occurs, for example, the ability is killed, an error message, in which **resultCode** is **-1**, is returned to the caller.
 - If different applications call this API to start an ability that uses the singleton mode and then call [terminateSelfWithResult](js-apis-inner-application-uiAbilityContext.md#uiabilitycontextterminateselfwithresult) to terminate the ability, the normal result is returned to the last caller, and an exception message, in which **resultCode** is **-1**, is returned to others.

Observe the following when using this API:
 - The application where the UIExtensionComponent is located must be running in the foreground and gain focus.
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **exported** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want |[Want](js-apis-app-ability-want.md) | Yes| Want information about the target ability.|
| options | [StartOptions](js-apis-app-ability-startOptions.md) | Yes| Parameters used for starting the ability.|
| callback | AsyncCallback&lt;[AbilityResult](js-apis-inner-ability-abilityResult.md)&gt; | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000001 | The specified ability does not exist. |
| 16000004 | Can not start invisible component. |
| 16000005 | The specified process does not have the permission. |
| 16000006 | Cross-user operations are not allowed. |
| 16000008 | The crowdtesting application expires. |
| 16000009 | An ability cannot be started or stopped in Wukong mode. |
| 16000011 | The context does not exist. |
| 16000012 | The application is controlled.        |
| 16000013 | The application is controlled by EDM.       |
| 16000050 | Internal error. |
| 16000053 | The ability is not on the top of the UI. |
| 16000055 | Installation-free timed out. |
| 16200001 | The caller has been released. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.startAbilityForResult

startAbilityForResult(want: Want, options?: StartOptions): Promise&lt;AbilityResult&gt;;

Starts an ability. This API uses a promise to return the result to the caller after the ability is terminated. An ability can be terminated in the following ways:
 - Normally, you can call [terminateSelfWithResult](js-apis-inner-application-uiAbilityContext.md#uiabilitycontextterminateselfwithresult) to terminate the ability. The result is returned to the caller.
 - If an exception occurs, for example, the ability is killed, an error message, in which **resultCode** is **-1**, is returned to the caller.
 - If different applications call this API to start an ability that uses the singleton mode and then call [terminateSelfWithResult](js-apis-inner-application-uiAbilityContext.md#uiabilitycontextterminateselfwithresult) to terminate the ability, the normal result is returned to the last caller, and an exception message, in which **resultCode** is **-1**, is returned to others.

Observe the following when using this API:
 - The application where the UIExtensionComponent is located must be running in the foreground and gain focus.
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **exported** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-app-ability-want.md) | Yes| Want information about the target ability.|
| options | [StartOptions](js-apis-app-ability-startOptions.md) | No| Parameters used for starting the ability.|


**Return value**

| Type| Description|
| -------- | -------- |
| Promise&lt;[AbilityResult](js-apis-inner-ability-abilityResult.md)&gt; | Promise used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000001 | The specified ability does not exist. |
| 16000002 | Incorrect ability type. |
| 16000004 | Can not start invisible component. |
| 16000005 | The specified process does not have the permission. |
| 16000006 | Cross-user operations are not allowed. |
| 16000008 | The crowdtesting application expires. |
| 16000009 | An ability cannot be started or stopped in Wukong mode. |
| 16000010 | The call with the continuation flag is forbidden. |
| 16000011 | The context does not exist. |
| 16000012 | The application is controlled.        |
| 16000013 | The application is controlled by EDM.       |
| 16000050 | Internal error. |
| 16000053 | The ability is not on the top of the UI. |
| 16000055 | Installation-free timed out. |
| 16200001 | The caller has been released. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.terminateSelf

terminateSelf(callback: AsyncCallback&lt;void&gt;): void;

Stops the window object corresponding to this **UIExtensionContentSession** instance. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| callback | AsyncCallback&lt;void&gt; | Yes| Callback used to return the result.|

## UIExtensionContentSession.terminateSelf

terminateSelf(): Promise&lt;void&gt;;

Stops the window object corresponding to this **UIExtensionContentSession** instance. This API uses a promise to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Return value**

| Type| Description|
| -------- | -------- |
| Promise&lt;void&gt; | Promise used to return the result.|

## UIExtensionContentSession.terminateSelfWithResult

terminateSelfWithResult(parameter: AbilityResult, callback: AsyncCallback&lt;void&gt;): void;

Stops the window object corresponding to this **UIExtensionContentSession** instance and returns the result to the UIExtensionComponent. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| parameter | [AbilityResult](js-apis-inner-ability-abilityResult.md) | Yes| Result returned to the UIExtensionComponent.|
| callback | AsyncCallback&lt;void&gt; | Yes| Callback used to return the result.|

## UIExtensionContentSession.terminateSelfWithResult

terminateSelfWithResult(parameter: AbilityResult): Promise&lt;void&gt;;

Stops the window object corresponding to this **UIExtensionContentSession** instance and returns the result to the UIExtensionComponent. This API uses a promise to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| parameter | [AbilityResult](js-apis-inner-ability-abilityResult.md) | Yes| Result returned to the UIExtensionComponent.|

**Return value**

| Type| Description|
| -------- | -------- |
| Promise&lt;void&gt; | Promise used to return the result.|

## UIExtensionContentSession.setWindowBackgroundColor

setWindowBackgroundColor(color: string): void

Sets the background color for the loading page of the UIExtensionAbility. This API must be used after [loadContent()](#uiextensioncontentsessionloadcontent) takes effect.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| color | string | Yes| Background color to set. The value is a hexadecimal RGB or ARGB color code and is case insensitive, for example, **#00FF00** or **#FF00FF00**.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000050 | Internal error. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.setWindowPrivacyMode

setWindowPrivacyMode(isPrivacyMode: boolean): Promise&lt;void&gt;

Sets whether the window is in privacy mode. This API uses a promise to return the result. A window in privacy mode cannot be captured or recorded.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Required permissions**: ohos.permission.PRIVACY_WINDOW

**Parameters**

| Name| Type| Mandatory| Description|
| ------------- | ------- | -- | ----------------------------------------------------- |
| isPrivacyMode | boolean | Yes| Whether the window is in privacy mode. The value **true** means that the window is in privacy mode, and **false** means the opposite.|

**Return value**

| Type| Description|
| ------------------- | ------------------------ |
| Promise&lt;void&gt; | Promise that returns no value.|

## UIExtensionContentSession.setWindowPrivacyMode

setWindowPrivacyMode(isPrivacyMode: boolean, callback: AsyncCallback&lt;void&gt;): void

Sets whether the window is in privacy mode. This API uses an asynchronous callback to return the result. A window in privacy mode cannot be captured or recorded.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Required permissions**: ohos.permission.PRIVACY_WINDOW

**Parameters**

| Name| Type| Mandatory| Description|
| ------------- | ------------------------- | -- | ------------------------------------------------------ |
| isPrivacyMode | boolean                   | Yes| Whether the window is in privacy mode. The value **true** means that the window is in privacy mode, and **false** means the opposite. |
| callback      | AsyncCallback&lt;void&gt; | Yes| Callback used to return the result.                                             |

## UIExtensionContentSession.startAbilityByType<sup>11+</sup>

startAbilityByType(type: string, wantParam: Record<string, Object>,
    abilityStartCallback: AbilityStartCallback, callback: AsyncCallback\<void>): void;

Implicitly starts a given type of UIExtensionAbility. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| type | string | Yes| Type of the UIExtensionAbility to start.|
| wantParam | {[key: string]: any} | Yes| Extended parameter.|
| abilityStartCallback | [AbilityStartCallback](js-apis-inner-application-abilityStartCallback.md) | Yes| Callback to be invoked when the startup fails.|
| callback | AsyncCallback\<void> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000001 | The specified ability does not exist. |
| 16000002 | Incorrect ability type. |
| 16000004 | Can not start invisible component. |
| 16000050 | Internal error. |
| 16200001 | The caller has been released. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.startAbilityByType<sup>11+</sup>

startAbilityByType(type: string, wantParam: Record<string, Object>,
    abilityStartCallback: AbilityStartCallback): Promise\<void>;

Implicitly starts a given type of UIExtensionAbility. This API uses a promise to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| type | string | Yes| Type of the UIExtensionAbility to start.|
| wantParam | {[key: string]: Object} | Yes| Extended parameter.|
| abilityStartCallback | [AbilityStartCallback](js-apis-inner-application-abilityStartCallback.md) | Yes| Callback to be invoked when the startup fails.|

**Return value**

| Type| Description|
| -------- | -------- |
| Promise\<void> | Promise that returns no value.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000001 | The specified ability does not exist. |
| 16000002 | Incorrect ability type. |
| 16000004 | Can not start invisible component. |
| 16000050 | Internal error. |
| 16200001 | The caller has been released. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.startAbilityAsCaller<sup>11+</sup>

startAbilityAsCaller(want: Want, callback: AsyncCallback\<void>): void

Starts an ability as the caller. This API uses an asynchronous callback to return the result.

The initial ability places its caller information (such as the bundle name and ability name) in the **want** parameter and transfers the information to an **ExtensionAbility** at the middle layer. When the ExtensionAbility starts another ability by calling this API, the started ability can obtain the caller information of the initial ability from the **onCreate** lifecycle.

**System API**: This is a system API.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-app-ability-want.md) | Yes| Want information about the target ability.|
| callback | AsyncCallback\<void> | Yes| Callback used to return the result. If the operation is successful, **err** is **undefined**; otherwise, **err** is an error object.|


**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000001 | The specified ability does not exist. |
| 16000002 | Incorrect ability type. |
| 16000004 | Can not start invisible component. |
| 16000005 | The specified process does not have the permission. |
| 16000006 | Cross-user operations are not allowed. |
| 16000008 | The crowdtesting application expires. |
| 16000009 | An ability cannot be started or stopped in Wukong mode. |
| 16000010 | The call with the continuation flag is forbidden. |
| 16000011 | The context does not exist. |
| 16000012 | The application is controlled. |
| 16000013 | The application is controlled by EDM. |
| 16000050 | Internal error. |
| 16000053 | The ability is not on the top of the UI. |
| 16000055 | Installation-free timed out. |
| 16200001 | The caller has been released. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.startAbilityAsCaller<sup>11+</sup>

startAbilityAsCaller(want: Want, options: StartOptions, callback: AsyncCallback\<void>): void

Starts an ability as the caller, with **options** specified. This API uses an asynchronous callback to return the result.

The initial ability places its caller information (such as the bundle name and ability name) in the **want** parameter and transfers the information to an **ExtensionAbility** at the middle layer. When the ExtensionAbility starts another ability by calling this API, the started ability can obtain the caller information of the initial ability from the **onCreate** lifecycle.

**System API**: This is a system API.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-app-ability-want.md) | Yes| Want information about the target ability.|
| options | [StartOptions](js-apis-app-ability-startOptions.md) | Yes| Parameters used for starting the ability.|
| callback | AsyncCallback\<void> | Yes| Callback used to return the result. If the operation is successful, **err** is **undefined**; otherwise, **err** is an error object.|


**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000001 | The specified ability does not exist. |
| 16000004 | Can not start invisible component. |
| 16000005 | The specified process does not have the permission. |
| 16000006 | Cross-user operations are not allowed. |
| 16000008 | The crowdtesting application expires. |
| 16000009 | An ability cannot be started or stopped in Wukong mode. |
| 16000011 | The context does not exist. |
| 16000012 | The application is controlled. |
| 16000013 | The application is controlled by EDM. |
| 16000050 | Internal error. |
| 16000053 | The ability is not on the top of the UI. |
| 16000055 | Installation-free timed out. |
| 16200001 | The caller has been released. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

## UIExtensionContentSession.startAbilityAsCaller<sup>11+</sup>

startAbilityAsCaller(want: Want, options?: StartOptions): Promise\<void>

Starts an ability as the caller. This API uses a promise to return the result.

The initial ability places its caller information (such as the bundle name and ability name) in the **want** parameter and transfers the information to an **ExtensionAbility** at the middle layer. When the ExtensionAbility starts another ability by calling this API, the started ability can obtain the caller information of the initial ability from the **onCreate** lifecycle.

**System API**: This is a system API.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-app-ability-want.md) | Yes| Want information about the target ability.|
| options | [StartOptions](js-apis-app-ability-startOptions.md) | No| Parameters used for starting the ability.|

**Return value**

| Type| Description|
| -------- | -------- |
| Promise\<void> | Promise that returns no value.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 16000001 | The specified ability does not exist. |
| 16000002 | Incorrect ability type. |
| 16000004 | Can not start invisible component. |
| 16000005 | The specified process does not have the permission. |
| 16000006 | Cross-user operations are not allowed. |
| 16000008 | The crowdtesting application expires. |
| 16000009 | An ability cannot be started or stopped in Wukong mode. |
| 16000010 | The call with the continuation flag is forbidden. |
| 16000011 | The context does not exist. |
| 16000012 | The application is controlled. |
| 16000013 | The application is controlled by EDM. |
| 16000050 | Internal error. |
| 16000053 | The ability is not on the top of the UI. |
| 16000055 | Installation-free timed out. |
| 16200001 | The caller has been released. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).