Listing credentials ids in gpg-agent

[Nielsen]

Hi all.

I'm wondering if there's an assuan command in the gpg-agent protocol
that lists the keyids for cached credentials.

I'm the author of seahorse-agent. It would be nice when gnupg2 comes out
 it could integrate with gpg-agent rather than trying to take the place
of gpg-agent.

To implement the seahorse-agent functionality of listing cached
credentials and allowing the user to clear them, I'd need to be able to
ask gpg-agent to list the ids for it's cache.

Any ideas? Or is this somehow a bad idea?

Cheers,
Nate Nielsen