Question about getting appointment slots and blocking slots already taken

Hi, just to confirm, is there a way we could book an appointment through the API and also get the list of available slots we could book? Or is the right approach to use the Job allocation API? Our main concern about using the job allocation API is that it would allow customers to book the same staff, same day, and same time, is there a way we could limit this so it blocks out the slot if someone has already booked?

Thanks,
Ralp