I am now doing plug-in development for a winfrom program. I want to realize the relevant functions through web and mobile phone app. What technology is generally needed or how to design it?

the current client program is the LAN deployment mode of cs architecture, and the local api can be called to read and write data.

want to know how to design a better expansibility in the future. For example, if you want to dock data for other programs in the future, you"d better directly open the data interface for others to call. What is the common practice at present? There is no web foundation, please try to be as detailed as possible, thank you first.