Mojo -> EventSource

# server sent events
get '/sse' => sub {
    my $self = shift;

    $self->res->headers->connection("Keep-Alive");
    $self->res->headers->content_type("text/event-stream");

    $c->{"$self"} = $self;

    $self->write("data:{"clientId":"foo"}\n\n");

    # ping
    Mojo::IOLoop->recurring(15 => sub {
        $self->write(":\n");
    });

    $self->on_finish(sub{
        delete $c->{"$self"};
    });
};


# later... you stream to all connected clients

if ( %$c ) {
    my $out = "data:".encode_json($data)."\n\n";
    foreach ( values %$c ) {
        $_->write($out);
    }
}