api for gpg?

[Sen Nagata]

hello-

  i am working on designing a pgp-enabled mailing list (list has
a key-pair type), and i was considering the possibility of using
gpg as the engine.  i hope this is an appropriate place to
ask questions.  please redirect me if it is not.

  can gpg be used in library form?  if so, i take it there isn't 
much documentation (bseides the source) :-)

  i am also curious whether there is some mode of operation to
support decryption followed by encryption in a single process
instance of gpg.  what i have in mind is to decrypt a message and 
then re-encrypt the result using multiple keys w/o having to pipe from 
one process (one that decrypts) to another (one that encrypts).

  thank you for your attention.

-sen