The Microsoft licensing and CALs (client access licenses), especially related to SQL access, is complicated and it's something Miles 33 normally does not deal with.

The main rule is: every application/script that access the database requires a CAL.

If more applications/scripts are on the same server they use one CAL.

Also the services, like the Alert, must be considerate.

Related to Web access there might be considered a special SQL version called SQL Web Server Edition or similar which has a different licensing method.

Depending from the number of clients it might be more convenient to buy a per-CPU license instead of CALs. This has to be evaluated on the customer level, also by visiting the Microsoft site or some forums.