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(** This module provides middlewares that is used by the RPC servers to
    forward unsupported RPCs to a full node. *)

(** A Resto middleware that transforms any callback to an other
    that rewrites queries that the proxy server cannot
    handle and forwards them to the full node at the given [Uri.t]. *)
val proxy_server_query_forwarder :
  Uri.t -> RPC_server.callback -> RPC_server.callback

(** A Resto middleware that transforms any server callback to an other
    that handles RPC metrics *)
val rpc_metrics_transform_callback :
  update_metrics:
    (string ->
    string ->
    (unit -> Cohttp_lwt_unix.Server.response_action Lwt.t) ->
    Cohttp_lwt_unix.Server.response_action Lwt.t) ->
  unit Tezos_rpc.Directory.t ->
  RPC_server.callback ->
  RPC_server.callback