excerpts from 'man gpg' that developers will likely want to use programmatically (biased by things I have had use cases for, and what I know from other devs)

gistfile1.txt

   Commands to select the type of operation

       --sign
       --clearsign
       --detach-sign
       --encrypt
       --symmetric
       --decrypt
       --multifile
       --verify-files
       --encrypt-files
       --decrypt-files
       --list-public-keys
       --list-secret-keys
       --check-sigs
       --fingerprint
       --delete-key
       --delete-secret-key
       --delete-secret-and-public-key
       --export
       --send-keys
       --import
       --recv-keys
       --refresh-keys
       --search-keys

... so, about half of the commands on the man page, I guess