The client tags are not available in the server environment, but the gateway can deliver information about all logged-in users via runScript(). Create an expression tag with the following one-liner:runScript("','.join([x['username'] for x in system.util.getSessionInfo()])")If you don’t want to include active designers, use this one:runScript("','.join([x['username'] for x in system.util.getSessionInfo() if not x['isDesigner']])")You can also place this in a triggered expression item that stores directly to the database.