> ## Documentation Index
> Fetch the complete documentation index at: https://docs.crossmint.com/llms.txt
> Use this file to discover all available pages before exploring further.

# CrossmintCheckoutLoadingBuilder

> Flutter Type Alias

**Type Alias**

Builder signature for the overlay rendered on top of the hosted checkout WebView while the hosted page is loading. Consumers can supply a custom builder via `CrossmintEmbeddedCheckout.loadingBuilder` to swap the default Material spinner for their own design-system loading state (Cupertino, fluent\_ui, a custom animation, etc.).

```dart theme={null}
typedef CrossmintCheckoutLoadingBuilder = Widget Function(BuildContext context)
```