1# @ohos.app.ability.ExtensionAbility (ExtensionAbility Base Class) 2 3**ExtensionAbility** is the base class for scenario-specific ExtensionAbilities. It is inherited from [Ability](js-apis-app-ability-ability.md), with no attribute or method added. You cannot inherit from this base class. 4 5> **NOTE** 6> 7> The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version. 8> The APIs of this module can be used only in the stage model. 9 10## Modules to Import 11 12```ts 13import ExtensionAbility from '@ohos.app.ability.ExtensionAbility'; 14``` 15 16**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore 17