S        This expression returns the IP address of the server you are currently connected to.


An IPv4 address will always be in the format "###.###.###.###", where ### are numbers between 0 and 255, inclusively.

An IPv6 address, in which case it will be in four-digit hexadecimal blocks separated by colons. For an example; "2001:0000:3238:DFE1:63::FEFB". It may be in square brackets [].

Due to IPv6's lengths, various shortening methods are applied; for example, 0000 will be reduced to 0.

IPv4 addresses mapped to IPv6 will look more like "::ffff:52e5:db02". Note that Blue will converted IPv4-mapped IPv6 addresses to their IPv4 counterpart for this expression.


You can read more under IPv6 section of Hosting a server.

HTML5/UWP note

In Blue Client HTML5 and UWP, the browser provides no way to give an IP address for a hostname.

This is because WebSocket connections start over HTTP/HTTPS, which provide a Host header, which tells the HTTP server which domain the client is trying to get on.

This allows one server machine to host multiple website domains. So connecting to the IP directly, or connecting to a different domain, could result in the same machine but being put on a different website.

Therefore, in HTML5 and UWP, this expression will return the original hostname you passed to the Connect action, rather than the IP address.