The documentation for Frontier::Daemon says:

Frontier::Daemon is a subclass of HTTP::Daemon, which is a subclass of IO::Socket::INET.

And IO::Socket::INET's documentation mentions a peeraddr() method. So $obj->peeraddr() may be useful [where $obj is value returned by Frontier::Daemon->new()]. I haven't tested this.

        - tye (but my friends call me "Tye")