When we design an x-callback-url action, we tend to focus on the x-success parameter because we want to get more things done. Yet, when we use these actions, especially the ones that involve two or more chained actions, sometimes we feel the need to cancel the first task and either return to the original app or continue with the second task. Either way, based on our most frequent use cases, we may need to revisit these chained actions and redesign them to include the x-cancel parameter.

Great point by Eric Pramono.

In my articles, I tend to omit x-cancel or only mention it in passing. But it’s essential if you want URL scheme-based workflows to fail gracefully.