In the process of rebuilding an existing app not made with Xojo. In that app we use sub-directories to store small text files that the app uses to identify the client and then customize the index page with name, styling, etc. So a client URL would look like:
if you simply wish to read the file and apply user-specific settings, or save such settings in the file, a folderitem with a text stream is probably better. The web application is really a console application that generates web pages on request. The web app can handle files just like a console application does.