# Widget Event Capability Overview

For dynamic ArkTS widgets, the [postCardAction](../reference/apis-arkui/js-apis-postCardAction.md#postcardaction) API is provided for interaction between the widget internal and the provider application. Currently, this API supports the router, message, and call events and can be called only in the widget.

For static ArkTS widgets, the [FormLink](../reference/apis-arkui/arkui-ts/ts-container-formlink.md) component is provided for interaction between the widget internal and the provider application.

## Dynamic Widget Event Capability
![WidgetPostCardAction](figures/WidgetPostCardAction.png)

Dynamic widget events are used in the following scenarios:
- Router event: used to redirect to a UIAbility and update the widget content.
- Call event: used to start a UIAbility in the background and update the widget content.
- Message event: used to start a FormExtensionAbility, which then updates the widget content.

## Static Widget Event Capability
See [FormLink](../reference/apis-arkui/arkui-ts/ts-container-formlink.md).