This is a great question. For now we do not support delete via the API. The best we can think of in the mean time is to use event.edit to make your event "private". This will hide the event from the majority of people -- any users except:
* friends of the user you added the event as (presumably none)
* people in Upcoming groups that you've added the event to (presumably none)
* anyone who has watchlisted the event (this is likely to affect some people -- you should probably also change the name of the event from "X" to "CANCELLED: X" or something like that)

In the future we would like to consider supporting event deletes with the API.

--- In yws-events@yahoogroups.com, "Andy" <andycarldavies@...> wrote:
>
> I have just started to look at the api with a view to developing an in-house app synchronise with Upcoming.
>
> I have noticed that there does not appear to be a delete event method. Is there a recommended approach to deleting events and maintaining parity between Upcoming and the calling app?
>
> Regards,
>
> Andy
>