Are there any naming convention guidelines for REST APIs? [closed]
I think you should avoid camel caps. The norm is to use lower case letters. I would also avoid underscores and use dashes instead
So your URL should look like this (ignoring the design issues as you requested :-))
api.service.com/hello-world/user-id/x
The REST API for Dropbox, Twitter, Google Web Services and Facebook all uses underscores.