HTTP query to get WAN inteface public IP address w/o using external service?

[fabrizior]

Is there a way to query the WAN public IP addresses via HTTP internally and anonymously without resorting to use an external service like https://whatsmyip.com?

I have some internal services (for better or worse) that want to phone home "just" to get the WAN IP for the running service instance. There's an ability to override the URL used for that lookup.

I'd rather have it request an internal URL and not resort to any external requests either directly or via proxy.

[stephenw10]

I guess it has to match the format required by those services?

There's nothing like that built into pfSense but I could imagine something that run on an internal host just to query the WAN IP and then serve it up as those services expect.
UPnP should be able to pull the external IP from pfSense if it's enabled.
Or maybe and SSH command.

Steve