# Open a URL in Workshop

To open a URL from a custom widget in Workshop, emit an [event](../parameters-and-events/index.md) and configure it in Workshop to trigger an `Open URL` Workshop event as a side effect.

This can be a simple static string URL, or a string variable URL that may be bound to a [parameter](../parameters-and-events/index.md) and updated in the same custom widget event.

:::callout{theme="warning"}
An asynchronous variable may not update before the `Open URL` event is run. For example, a direct update of a string variable URL as part of the custom widget event is synchronous, but a downstream variable transform to build the string variable URL would be asynchronous.
:::

!["Open URL" Workshop event configuration.](../../../assets/739b3e1d82fde5c9e8b3b709a62d295d00563742afeeba454a5454ad2fe6089b.webp)

When opening external URLs, this may trigger a warning dialog.

![External link dialog in Workshop.](../../../assets/d66829b4428a58212f18df9c0a6e8feae66cee59969a4f7b7dbfd82b4cc04262.webp)