You can search for identifiers within the package.
in-package search v0.2.0
val start : ?addr:string -> ?port:int -> ((Message.t, error) result -> Message.t Lwt.t) -> unit Lwt.t
start ~addr ~port handler starts the CoAP server in a Lwt thread listening for client requests on the provided IPv4 or IPv6 address/port and handling incoming requests with the handler function.
start ~addr ~port handler
handler