Good question. The short answer's no, POE::Component::Client::HTTP doesn't expose the connection manager it uses. It also doesn't have a way to be shut down ahead of time, which hasn't been needed until now.

If you're creating your own POE::Component::Client::Keepalive and passing that as the ConnectionManager, however, you still have $cm floating around, and you can shut that down without ill effects. Caveat: I've only tried this in your example program, and only when there are no outstanding requests.