1# CustomData (System API) 2 3 4When starting a modal page, you can transfer custom data to the autofill service through [reloadInModal](js-apis-inner-application-autoFillExtensionContext-sys.md) and obtain the data through [onFillRequest](js-apis-app-ability-autoFillExtensionAbility-sys.md) of the service. 5 6> **NOTE** 7> 8> The initial APIs of this module are supported since API version 13. Newly added APIs will be marked with a superscript to indicate their earliest API version. 9> The APIs of this module can be used only in the stage model. 10> The APIs provided by this module are system APIs. 11 12## Properties 13 14**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore 15 16| Name| Type | Read-Only| Optional| Description | 17| ---- | ---------------------- | ---- | ---- | ---------------------------------------------------- | 18| data | Record<string, Object> | No | No | Custom data transferred for starting the modal page. The data is of the Record type.| 19