The htmx.config.requestClass option sets the CSS class htmx adds while a request is running.
htmx adds it to the element selected by hx-indicator. Without hx-indicator, htmx adds it to the request source.
Default: "htmx-request"
Usage
Use a custom request-state class:
<meta name="htmx-config" content='requestClass:"is-loading"'>
.is-loading { opacity: 0.5; }
htmx removes the class when the request ends.