What should be needing then is standardized commands to indicate which APIs it implements (which might be more than one) for any kind of web app services that m

What should be needing then is standardized commands to indicate which APIs it implements (which might be more than one) for any kind of web app services that may be available on multiple instances on multiple servers, that you can identify them and be able to work. Unfortunately, it seem that some do not do that (including Fossil; I tried to tell them to add such a thing but they don't want to do; I run my own Fossil and would want to expose some command to indicate its presence instead of being forced to use the built-in user interface).