I think you need that extra showValue for when the widget is updated by another widget, for example for Inputs.bind

It seems like Inputs.bind dispatches an event: https://github.com/observablehq/inputs/blob/7ae53c757080b99ca3b498653cf2bc49bf8125a1/src/bind.js#L7 It's very, very nity anyways

Yes, and then the reactive widget captures the event and calls setValue, which then needs to call showValue

But there is already a listener that triggers showValue: target.addEventListener("input", showValue) which is why I think the call is redundant. When I'm using the pattern I can experiment if showValue isn't very cheap (it usually is)