In the Genero Application Server architecture, a request to start a Genero application comes in via a Web Server that results in the launch of the application. The Web Server has some information about the request and that information can be passed through to the Genero application. This includes information such as the IP address.
The techniques to retrieve this information are different for a web application and a web service. With a web application this information is passed through as an environment variable, whilst for a web service this is passed through as a request header and can be read in a number of different ways.
A common error is to try and utilise the technique for a web application with a web service.
Read more about these techniques and why there is a difference at
https://4js.com/ask-reuben/ig-49/