You can search for identifiers within the package.
in-package search v0.2.0
type error = [
| `No_entropy_device of string
]
type 'a io = 'a Lwt.t
type t
type id = unit
val disconnect : t -> unit io
type buffer = Cstruct.t
type handler = source:int -> buffer -> unit
val handler : t -> handler -> unit io
val connect : unit -> [ `Error of error | `Ok of t ] io