Currently APISite includes hard-coded lists of tokens. These lists should instead be obtained using the API paraminfo. The API token interface has changed a few times, and therefore depending on the version, the list of tokens for the site is found in the paraminfo of different modules.
http://www.wikia.com/api.php?format=jsonfm&action=paraminfo&querymodules=info
http://en.wikipedia.org/w/api.php?format=jsonfm&action=paraminfo&querymodules=tokens