We are trying to build a stand-alone API, which has to meet this requirement.
The API gets inputs for "Name" & "Email" and should then create user in any chosen Sitecore instance.
As this is a stand-alone API, it will have to make use of Sitecore dlls & configs, to be able to do what is required. But will this be violating the license.
One way, that I know of, is to host this service/API in the Sitecore instance itself. These user creation requests are huge in number, so can't have them in CD. Also, is it advisable to have such an API in CM which should be secure.
I would appreciate any suggestions to achieve this functionality.