1# AbilityFirstFrameStateObserver (System API) 2 3**AbilityFirstFrameStateObserver** defines the observer used to listen for the complete of the first frame rendering of a given ability. It is used as an input parameter of [on](js-apis-app-ability-appManager-sys.md#appmanageronabilityfirstframestate12) to listen for the completion event. 4 5> **NOTE** 6> 7> The initial APIs of this module are supported since API version 12. Newly added APIs will be marked with a superscript to indicate their earliest API version. 8> The APIs provided by this module are system APIs. 9 10## Modules to Import 11 12```ts 13import { appManager } from '@kit.AbilityKit'; 14``` 15 16## Properties 17 18**System API**: This is a system API. 19 20**System capability**: SystemCapability.Ability.AbilityRuntime.Core 21 22| Name | Type | Read Only| Mandatory| Description | 23| ------------------------ | -------------------- | ---- | ---- | ------------------------------------------------------------ | 24| onAbilityFirstFrameDrawn | AsyncCallback\<void> | Yes | No | Callback invoked when the first frame of an ability is rendered. The parameter type passed in is [AbilityFirstFrameStateData](js-apis-inner-application-abilityFirstFrameStateData-sys).| 25