---
title: "ShelfWidgetPrewarmPolicy, DroppyKit"
description: "Whether the shelf may mount the widget invisibly ahead of time."
canonical: "https://getdroppy.app/docs/droppykit/api/shelf-widget-prewarm-policy"
last-updated: "2026-09-09"
---

# ShelfWidgetPrewarmPolicy

Whether the shelf may mount the widget invisibly ahead of time.

`enum ShelfWidgetPrewarmPolicy`

Current hosts never prewarm external widgets (the safe direction, since prewarming runs code invisibly), so today `.allowed` is a permission the host does not yet use, and `.never` is the guarantee it already keeps. Declare `.never` whenever mounting has user-visible side effects so a future host that does prewarm externals cannot get it wrong.

## Cases

### ShelfWidgetPrewarmPolicy.allowed

`case allowed`

The shelf may prewarm the widget for smoother first opens.

### ShelfWidgetPrewarmPolicy.never

`case never`

Never prewarm. Use when mounting has side effects the user must see, for example a camera widget lighting the privacy LED.