1# @ohos.app.ability.ExtensionAbility (ExtensionAbility Base Class) 2 3**ExtensionAbility** is the base class for scenario-specific ExtensionAbilities. It provides the callbacks for system configuration updates and memory level updates. 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 18**Example** 19 20 ```ts 21 class MyExtensionAbility extends ExtensionAbility { 22 onConfigurationUpdated(config) { 23 console.log('onConfigurationUpdated, config:' + JSON.stringify(config)); 24 } 25 26 onMemoryLevel(level) { 27 console.log('onMemoryLevel, level:' + JSON.stringify(level)); 28 } 29 } 30 ``` 31 32