[_ck_]

There’s no official documentation or codex yet.

A few people have done phpxref for bbpress but I find that kind of output fairly useless.

If you have access to linux shell you can do a grep to get a function list in the template include like so (or install the grep for windows)

grep -oe ^function.*) bb-includes/template-functions.php | sort > functions.txt

modifying that you can also get the filters/actions

grep -oe apply_.*) bb-includes/template-functions.php | sort > filters.txt

grep -oe do_.*) bb-includes/template-functions.php | sort > actions.txt

If you use the grep for windows, leave out the escapes (backslashes) or it won’t work.