Traffic by minute would provide great insights for businesses that rely on specific events that last for one hour or so.
That's good news.
Can I have that on Ad Hoc report or SiteCatalyst v14?
No, it is only available in Reports & Analytics (SC 15) currently. There is also an API so that you can pull minute-by-minute data into your own applications.
How does the API work?
Is there any guidelines?
The developer connection should have all the information you need to access real time data via the API.