You can search for identifiers within the package.
in-package search v0.2.0
type 'a key
type secret_key = secret key
type auth
val primitive : string
val key_size : int
val auth_size : int
val random_key : unit -> secret key
val wipe_key : secret key -> unit
val equal_keys : secret key -> secret key -> bool
module type S = sig ... end
module Bytes : sig ... end
module Bigbytes : sig ... end