afaik (please somebody correct me if i'm wrong) if you pay for a bloomberg workstation you can download API and use it on your system, but you're limited to using it on a licensed workstation (you cant interface another system in order to pull these data) and you cant pass it without elaborating them
so, as example:
NO you cant use a program on the licensed workstation that sucks data and push them to a database that is used to power a website that shows stock prices
NO you cant get the data from that workstation from other computers via API
YES you can create a custom C++ program that runs on your licensed bloomberg workstation that get data via API, elaborate them with your own algo and give you signals for buy/sell (or maybe create a report that you send to your customers)
This is basically correct. Anyone with a terminal can program against it and use the "desktop" API (the SDK connecting to the terminal). The same for any customer with just an API appliance.
To extend your example, some customers use it to process realtime data, mix in their own data that they do not want to leave their network, then perform some kind of algo on it, and ultimately use the API SDK to feed the results back to Bloomberg for publishing. The SDK is used by publishers who feed content to us -- it isn't just for receiving data.
so, as example:
NO you cant use a program on the licensed workstation that sucks data and push them to a database that is used to power a website that shows stock prices
NO you cant get the data from that workstation from other computers via API
YES you can create a custom C++ program that runs on your licensed bloomberg workstation that get data via API, elaborate them with your own algo and give you signals for buy/sell (or maybe create a report that you send to your customers)