diff --git a/src/extensions/authbasic.ml b/src/extensions/authbasic.ml
index 1c8e005d7..ea2670dbd 100644
--- a/src/extensions/authbasic.ml
+++ b/src/extensions/authbasic.ml
@@ -111,7 +111,4 @@ let () =
     ()
 
 (** Instruction for static linking without config file: *)
-let instruction ~realm ~auth () _ _ _ = gen ~realm ~auth
-
-let run ?site ~realm ~auth () =
-  Ocsigen_server.Site.register ?site (instruction ~realm ~auth ())
+let run ~realm ~auth () _ _ _ = gen ~realm ~auth
diff --git a/src/extensions/authbasic.mli b/src/extensions/authbasic.mli
index 118fb5970..ea1259504 100644
--- a/src/extensions/authbasic.mli
+++ b/src/extensions/authbasic.mli
@@ -59,13 +59,8 @@ val register_basic_authentication_method : (Xml.xml -> auth) -> unit
     from the point of view of plugin developers and is totally
     transparent to the plugin. *)
 
-val run :
-   ?site:Ocsigen_server.Site.t
-  -> realm:string
-  -> auth:auth
-  -> unit
-  -> unit
-(** [run ~realm ~auth ()] makes it possible to use this extension without 
+val run : realm:string -> auth:auth -> unit -> Ocsigen_server.instruction
+(** [run ~realm ~auth ()] makes it possible to use this extension without
     configuration file.  *)
 
 (**/**)
diff --git a/src/extensions/cors.ml b/src/extensions/cors.ml
index 2de2e5d28..273f2a059 100644
--- a/src/extensions/cors.ml
+++ b/src/extensions/cors.ml
@@ -156,11 +156,7 @@ let () =
     ~fun_site:(fun _ _ _ -> parse_config)
     ()
 
-let instruction ?credentials ?max_age ?exposed_headers ?methods () _ _ _ =
+let run ?credentials ?max_age ?exposed_headers ?methods () _ _ _ =
   let credentials = Ocsigen_lib.Option.get' false credentials in
   let exposed_headers = Ocsigen_lib.Option.get' [] exposed_headers in
   main {credentials; methods; max_age; exposed_headers}
-
-let run ?site ?credentials ?max_age ?exposed_headers ?methods () =
-  Ocsigen_server.Site.register ?site
-    (instruction ?credentials ?max_age ?exposed_headers ?methods ())
diff --git a/src/extensions/cors.mli b/src/extensions/cors.mli
index a604b50e3..239eeb666 100644
--- a/src/extensions/cors.mli
+++ b/src/extensions/cors.mli
@@ -1,8 +1,7 @@
 val run :
-   ?site:Ocsigen_server.Site.t
-  -> ?credentials:bool
+   ?credentials:bool
   -> ?max_age:int
   -> ?exposed_headers:string list
   -> ?methods:Cohttp.Code.meth list
   -> unit
-  -> unit
+  -> Ocsigen_server.instruction
diff --git a/src/extensions/deflatemod.ml b/src/extensions/deflatemod.ml
index ed7ce96e3..76fe927ba 100644
--- a/src/extensions/deflatemod.ml
+++ b/src/extensions/deflatemod.ml
@@ -366,7 +366,4 @@ let () =
     ~fun_site:(fun _ _ _ _ _ _ -> parse_config)
     ~init_fun:parse_global_config ()
 
-let instruction ~mode () _ _ _ = filter mode
-
-let run ?site ~mode () =
-  Ocsigen_server.Site.register ?site (instruction ~mode ())
+let run ~mode () _ _ _ = filter mode
diff --git a/src/extensions/deflatemod.mli b/src/extensions/deflatemod.mli
index b9e3a7db7..3fc99be6f 100644
--- a/src/extensions/deflatemod.mli
+++ b/src/extensions/deflatemod.mli
@@ -7,7 +7,6 @@ val set_buffer_size : int -> unit
 type filter = [`Type of string option * string option | `Extension of string]
 
 val run :
-   ?site:Ocsigen_server.Site.t
-  -> mode:[`All_but of filter list | `Only of filter list]
-  -> unit
+   mode:[`All_but of filter list | `Only of filter list]
   -> unit
+  -> Ocsigen_server.instruction
diff --git a/src/extensions/outputfilter.ml b/src/extensions/outputfilter.ml
index 30cc1c506..08167bb0d 100644
--- a/src/extensions/outputfilter.ml
+++ b/src/extensions/outputfilter.ml
@@ -116,8 +116,5 @@ let () =
     ~fun_site:(fun _ _ _ _ _ _ -> parse_config)
     ()
 
-let instruction ~mode () _ _ _ =
+let run ~mode () _ _ _ =
   match mode with `Code c -> gen_code c | #header_filter as f -> gen f
-
-let run ?site ~mode () =
-  Ocsigen_server.Site.register ?site (instruction ~mode ())
diff --git a/src/extensions/outputfilter.mli b/src/extensions/outputfilter.mli
index f1d4ffa40..06551ffad 100644
--- a/src/extensions/outputfilter.mli
+++ b/src/extensions/outputfilter.mli
@@ -1,8 +1,7 @@
 val run :
-   ?site:Ocsigen_server.Site.t
-  -> mode:
-       [ `Rewrite of Ocsigen_header.Name.t * Re.Pcre.regexp * string
-       | `Add of Ocsigen_header.Name.t * string * bool option
-       | `Code of Cohttp.Code.status ]
-  -> unit
+   mode:
+     [ `Rewrite of Ocsigen_header.Name.t * Re.Pcre.regexp * string
+     | `Add of Ocsigen_header.Name.t * string * bool option
+     | `Code of Cohttp.Code.status ]
   -> unit
+  -> Ocsigen_server.instruction
diff --git a/src/extensions/redirectmod.ml b/src/extensions/redirectmod.ml
index 9912d61e5..1c65647fd 100644
--- a/src/extensions/redirectmod.ml
+++ b/src/extensions/redirectmod.ml
@@ -112,7 +112,4 @@ let () =
     ~fun_site:(fun _ _ _ _ _ _ -> parse_config)
     ()
 
-let instruction ~redirection () _ _ _ = gen redirection
-
-let run ?site ~redirection () =
-  Ocsigen_server.Site.register ?site (instruction ~redirection ())
+let run ~redirection () _ _ _ = gen redirection
diff --git a/src/extensions/redirectmod.mli b/src/extensions/redirectmod.mli
index 4c4b15ce9..711f4b1c1 100644
--- a/src/extensions/redirectmod.mli
+++ b/src/extensions/redirectmod.mli
@@ -10,4 +10,4 @@ val create_redirection :
   -> string
   -> redirection
 
-val run : ?site:Ocsigen_server.Site.t -> redirection:redirection -> unit -> unit
+val run : redirection:redirection -> unit -> Ocsigen_server.instruction
diff --git a/src/extensions/revproxy.ml b/src/extensions/revproxy.ml
index 79c5d3b43..3143bccd2 100644
--- a/src/extensions/revproxy.ml
+++ b/src/extensions/revproxy.ml
@@ -197,7 +197,4 @@ let () =
                               when sending to extensions! *)
     ()
 
-let instruction ~redirection () _ _ _ = gen redirection
-
-let run ?site ~redirection () =
-  Ocsigen_server.Site.register ?site (instruction ~redirection ())
+let run ~redirection () _ _ _ = gen redirection
diff --git a/src/extensions/revproxy.mli b/src/extensions/revproxy.mli
index 7e2e5949b..a5c8f842a 100644
--- a/src/extensions/revproxy.mli
+++ b/src/extensions/revproxy.mli
@@ -11,4 +11,4 @@ val create_redirection :
   -> string
   -> redirection
 
-val run : ?site:Ocsigen_server.Site.t -> redirection:redirection -> unit -> unit
+val run : redirection:redirection -> unit -> Ocsigen_server.instruction
diff --git a/src/extensions/rewritemod.ml b/src/extensions/rewritemod.ml
index 073cdd36a..a8e272f82 100644
--- a/src/extensions/rewritemod.ml
+++ b/src/extensions/rewritemod.ml
@@ -128,16 +128,10 @@ let () =
     ~fun_site:(fun _ _ _ _ _ _ -> parse_config)
     ()
 
-let instruction ?(continue = false) ?(full_rewrite = false) ~regexp dest () _ _
-    _
-  =
+let run ?(continue = false) ?(full_rewrite = false) ~regexp dest () _ _ _ =
   gen
     (Regexp
        ( Ocsigen_lib.Netstring_pcre.regexp ("^" ^ regexp ^ "$")
        , dest
        , full_rewrite ))
     continue
-
-let run ?site ?continue ?full_rewrite ~regexp dest () =
-  Ocsigen_server.Site.register ?site
-    (instruction ?continue ?full_rewrite ~regexp dest ())
diff --git a/src/extensions/rewritemod.mli b/src/extensions/rewritemod.mli
index ba60ae605..7b4c52275 100644
--- a/src/extensions/rewritemod.mli
+++ b/src/extensions/rewritemod.mli
@@ -2,10 +2,9 @@ val section : Lwt_log_core.section
 (** use Lwt_log.Section.set_level in order to debug *)
 
 val run :
-   ?site:Ocsigen_server.Site.t
-  -> ?continue:bool
+   ?continue:bool
   -> ?full_rewrite:bool
   -> regexp:string
   -> string
   -> unit
-  -> unit
+  -> Ocsigen_server.instruction
diff --git a/src/extensions/staticmod.ml b/src/extensions/staticmod.ml
index a9bd94ef9..a6af87930 100644
--- a/src/extensions/staticmod.ml
+++ b/src/extensions/staticmod.ml
@@ -281,7 +281,7 @@ let () =
 (* Registration for static linking: *)
 let preprocess s = "^" ^ s ^ "$"
 
-let instruction ?dir ?regexp ?dest ?code ?cache ?root () =
+let run ?dir ?regexp ?dest ?code ?cache ?root () =
   let kind =
     kind dir
       (Ocsigen_lib.Option.map (fun x -> Pcre.regexp (preprocess x)) regexp)
@@ -296,7 +296,3 @@ let instruction ?dir ?regexp ?dest ?code ?cache ?root () =
          root)
   in
   fun _ _ _ -> gen ~usermode:None ?cache kind
-
-let run ?site ?dir ?regexp ?dest ?code ?cache ?root () =
-  Ocsigen_server.Site.register ?site
-    (instruction ?dir ?regexp ?dest ?code ?cache ?root ())
diff --git a/src/extensions/staticmod.mli b/src/extensions/staticmod.mli
index ac33141f0..4d202fe46 100644
--- a/src/extensions/staticmod.mli
+++ b/src/extensions/staticmod.mli
@@ -2,14 +2,13 @@ val section : Lwt_log_core.section
 (** use Lwt_log.Section.set_level in order to debug *)
 
 val run :
-   ?site:Ocsigen_server.Site.t
-  -> ?dir:string
+   ?dir:string
   -> ?regexp:string
   -> ?dest:string
   -> ?code:string
   -> ?cache:int
   -> ?root:string
   -> unit
-  -> unit
+  -> Ocsigen_server.instruction
 (** Run static mod on a specific directory. 
     Call this if you want to run Ocsigen Server without configuration file. *)
diff --git a/src/ocsigenserver.ml b/src/ocsigenserver.ml
index 3727ac321..072bb9718 100644
--- a/src/ocsigenserver.ml
+++ b/src/ocsigenserver.ml
@@ -31,4 +31,4 @@ let () =
       "usage: ocsigenserver [-c configfile]"
   with Arg.Help s -> print_endline s; exit 0
 
-let () = Ocsigen_server.start ~config:(Ocsigen_parseconfig.parse_config ()) ()
+let () = Ocsigen_server.exec (Ocsigen_parseconfig.parse_config ())
diff --git a/src/server/ocsigen_extensions.ml b/src/server/ocsigen_extensions.ml
index 4ac19f1e3..3eb0737b9 100644
--- a/src/server/ocsigen_extensions.ml
+++ b/src/server/ocsigen_extensions.ml
@@ -258,9 +258,9 @@ type parse_fun = Xml.xml list -> extension_composite
 type parse_host =
   | Parse_host of (Url.path -> parse_host -> parse_fun -> Xml.xml -> extension)
 
-let hosts : (virtual_hosts * config_info * extension_composite) list ref =
-  ref []
+type host_config = virtual_hosts * config_info * extension_composite
 
+let hosts : host_config list ref = ref []
 let set_hosts v = hosts := v
 let get_hosts () = !hosts
 
diff --git a/src/server/ocsigen_extensions.mli b/src/server/ocsigen_extensions.mli
index db1e336ba..92c012819 100644
--- a/src/server/ocsigen_extensions.mli
+++ b/src/server/ocsigen_extensions.mli
@@ -406,7 +406,9 @@ val site_ext :
   -> Ocsigen_lib.Url.path
   -> extension
 
-val set_hosts : (virtual_hosts * config_info * extension_composite) list -> unit
+type host_config = virtual_hosts * config_info * extension_composite
+
+val set_hosts : host_config list -> unit
 val get_hosts : unit -> (virtual_hosts * config_info * extension_composite) list
 
 val compute_result :
@@ -416,9 +418,9 @@ val compute_result :
 (** Compute the answer to be sent to the client, by trying all
     extensions according the configuration file. *)
 
-val get_number_of_connected : unit -> int
-(** Profiling *)
+(** {3 Profiling} *)
 
+val get_number_of_connected : unit -> int
 val during_initialisation : unit -> bool
 val start_initialisation : unit -> unit
 val end_initialisation : unit -> unit
diff --git a/src/server/ocsigen_server.ml b/src/server/ocsigen_server.ml
index 8e5983d0a..f7642e37f 100644
--- a/src/server/ocsigen_server.ml
+++ b/src/server/ocsigen_server.ml
@@ -122,93 +122,60 @@ let _ =
   in
   Ocsigen_command.register_command_function f
 
-module Site = struct
-  type instruction =
-    Ocsigen_extensions.virtual_hosts
-    -> Ocsigen_extensions.config_info
-    -> Ocsigen_lib.Url.path
-    -> Ocsigen_extensions.extension
+type instruction =
+  Ocsigen_extensions.virtual_hosts
+  -> Ocsigen_extensions.config_info
+  -> Ocsigen_lib.Url.path
+  -> Ocsigen_extensions.extension
 
-  type t =
-    { s_id :
-        [ `Host of Ocsigen_extensions.virtual_hosts
-        | `Attach of t * Ocsigen_lib.Url.path ]
-    ; s_config_info : Ocsigen_extensions.config_info
-    ; s_charset : Ocsigen_charset_mime.charset option
-    ; mutable s_children_l :
-        [`Instruction of Ocsigen_extensions.extension | `Child of t] list }
+let default_re_string = ".*"
 
-  (** host list *)
-  let l = ref []
-
-  let default_re_string = ".*"
-  let default_re = Ocsigen_lib.Netstring_pcre.regexp default_re_string
-
-  let rec path_and_hosts {s_id; _} =
-    match s_id with
-    | `Host hosts -> [], hosts
-    | `Attach (s, path') ->
-        let path, hosts = path_and_hosts s in
-        path @ path', hosts
-
-  let create ?(config_info = Ocsigen_extensions.default_config_info ())
-      ?(id = `Host (default_re_string, None)) ?charset ()
-    =
-    let s_id =
-      match id with
-      | `Host (host_regexp, port) when host_regexp = default_re_string ->
-          `Host [default_re_string, default_re, port]
-      | `Host (host_regexp, port) ->
-          `Host
-            [host_regexp, Ocsigen_lib.Netstring_pcre.regexp host_regexp, port]
-      | `Attach (parent, path) ->
-          `Attach (parent, Ocsigen_extensions.preprocess_site_path path)
-    in
-    let s =
-      {s_id; s_charset = charset; s_config_info = config_info; s_children_l = []}
-    in
-    (match s_id with
-    | `Host _ -> l := s :: !l
-    | `Attach (parent, _) ->
-        parent.s_children_l <- `Child s :: parent.s_children_l);
-    s
-
-  let default_host = create ()
-
-  let register ?(site = default_host) f =
-    let {s_config_info; s_children_l; _} = site in
-    let path, hosts = path_and_hosts site in
-    site.s_children_l <-
-      `Instruction (f hosts s_config_info path) :: s_children_l
-
-  let rec dump_host path {s_children_l; _} =
-    let f = function
-      | `Instruction f -> f
-      | `Child ({s_charset; s_id = `Attach (_, path'); _} as s) ->
-          let path = path @ path' in
-          Ocsigen_extensions.site_ext (dump_host path s) s_charset path
-      | `Child _ -> failwith "Ocsigen_server.dump_host"
-    in
-    Ocsigen_extensions.compose (List.map f (List.rev s_children_l))
+let host ?(re = default_re_string) ?port ?default_hostname ?default_httpport
+    ?default_httpsport ?default_protocol_is_https ?mime_assoc ?charset_assoc
+    ?default_directory_index ?list_directory_content ?follow_symlinks
+    ?do_not_serve_404 ?do_not_serve_403 ?uploaddir ?maxuploadfilesize
+    instructions
+  =
+  let def = Ocsigen_extensions.default_config_info () in
+  let default default o = Option.value o ~default in
+  let config_info =
+    { Ocsigen_extensions.default_hostname =
+        default def.default_hostname default_hostname
+    ; default_httpport = default def.default_httpport default_httpport
+    ; default_httpsport = default def.default_httpsport default_httpsport
+    ; default_protocol_is_https =
+        default def.default_protocol_is_https default_protocol_is_https
+    ; mime_assoc = default def.mime_assoc mime_assoc
+    ; charset_assoc = default def.charset_assoc charset_assoc
+    ; default_directory_index =
+        default def.default_directory_index default_directory_index
+    ; list_directory_content =
+        default def.list_directory_content list_directory_content
+    ; follow_symlinks = default def.follow_symlinks follow_symlinks
+    ; do_not_serve_404 = default def.do_not_serve_404 do_not_serve_404
+    ; do_not_serve_403 = default def.do_not_serve_403 do_not_serve_403
+    ; uploaddir = default def.uploaddir uploaddir
+    ; maxuploadfilesize = default def.maxuploadfilesize maxuploadfilesize }
+  in
+  let vh = [re, Ocsigen_lib.Netstring_pcre.regexp re, port] in
+  ( vh
+  , config_info
+  , Ocsigen_extensions.compose
+      (List.map (fun i -> i vh config_info []) instructions) )
 
-  let dump () =
-    let f acc = function
-      | {s_config_info; s_id = `Host l; s_children_l = _ :: _; _} as s ->
-          (l, s_config_info, dump_host [] s) :: acc
-      | _ -> acc
-    in
-    Ocsigen_extensions.set_hosts (List.fold_left f [] !l)
-end
+let site ?charset path instructions vh config_info parent_path =
+  let path = parent_path @ Ocsigen_extensions.preprocess_site_path path in
+  let composite =
+    Ocsigen_extensions.compose
+      (List.map (fun i -> i vh config_info path) instructions)
+  in
+  Ocsigen_extensions.site_ext composite charset path
 
-let start ?config () =
+let main config =
   try
     (* initialization functions for modules (Ocsigen extensions or application
        code) loaded from now on will be executed directly. *)
     Ocsigen_loader.set_init_on_load true;
-    (match config with
-    | Some (_ :: _ :: _) ->
-        Lwt_log.ign_warning ~section "Multiple servers not supported anymore"
-    | _ -> ());
     let ask_for_passwd sslports _ =
       print_string
         "Please enter the password for the HTTPS server listening on port(s) ";
@@ -231,7 +198,7 @@ let start ?config () =
         raise exn
     in
     let extensions_connector = Ocsigen_extensions.compute_result in
-    let run s =
+    let run () =
       let user = Ocsigen_config.get_user ()
       and group = Ocsigen_config.get_group () in
       Lwt_main.run (Ocsigen_messages.open_files ~user ~group ());
@@ -319,19 +286,8 @@ let start ?config () =
            match e with
            | Unix.Unix_error (Unix.EPIPE, _, _) -> ()
            | _ -> Lwt_log.ign_error ~section ~exn:e "Uncaught Exception");
-      (match s with
-      | Some s ->
-          (* Now I can load the modules *)
-          Dynlink_wrapper.allow_unsafe_modules true;
-          Ocsigen_extensions.start_initialisation ();
-          Ocsigen_parseconfig.later_pass s;
-          (* As libraries are reloaded each time the config file is
-            read, we do not allow to register extensions in
-            libraries. Seems it does not work :-/ *)
-          Dynlink_wrapper.prohibit ["Ocsigen_extensions.R"]
-      | None ->
-          Ocsigen_extensions.start_initialisation ();
-          Site.dump ());
+      (* Now apply host configuration: *)
+      config ();
       if Ocsigen_config.get_silent ()
       then (
         (* Close stderr, stdout stdin if silent *)
@@ -421,31 +377,46 @@ let start ?config () =
           ignore (Unix.write_substring f spid 0 len);
           Unix.close f
     in
-    let launch h =
-      Ocsigen_lib.Option.iter Ocsigen_parseconfig.first_pass h;
-      (* set_passwd_if_needed sslinfo; *)
-      if Ocsigen_config.get_daemon ()
-      then
-        let pid = Unix.fork () in
-        if pid = 0
-        then run h
-        else (
-          Ocsigen_messages.console (fun () ->
-            "Process " ^ string_of_int pid ^ " detached");
-          write_pid pid)
+    (* set_passwd_if_needed sslinfo; *)
+    if Ocsigen_config.get_daemon ()
+    then
+      let pid = Unix.fork () in
+      if pid = 0
+      then run ()
       else (
-        write_pid (Unix.getpid ());
-        run h)
-    in
-    let launch = function
-      | Some [] -> ()
-      | Some [h] -> launch (Some h)
-      | None -> launch None
-      | Some (_ :: _ :: _) -> ()
-      (* Multiple servers not supported any more *)
-    in
-    launch config
+        Ocsigen_messages.console (fun () ->
+          "Process " ^ string_of_int pid ^ " detached");
+        write_pid pid)
+    else (
+      write_pid (Unix.getpid ());
+      run ())
   with e ->
     let msg, errno = errmsg e in
     Ocsigen_messages.errlog msg;
     exit errno
+
+let exec = function
+  | [] -> ()
+  | [h] ->
+      (try Ocsigen_parseconfig.first_pass h
+       with e ->
+         let msg, errno = errmsg e in
+         Ocsigen_messages.errlog msg;
+         exit errno);
+      main (fun () ->
+        (* Now I can load the modules *)
+        Dynlink_wrapper.allow_unsafe_modules true;
+        Ocsigen_extensions.start_initialisation ();
+        Ocsigen_parseconfig.later_pass h;
+        (* As libraries are reloaded each time the config file is
+          read, we do not allow to register extensions in
+          libraries. Seems it does not work :-/ *)
+        Dynlink_wrapper.prohibit ["Ocsigen_extensions.R"])
+  | _ :: _ :: _ ->
+      Lwt_log.ign_warning ~section "Multiple servers not supported anymore"
+(* Multiple servers not supported any more *)
+
+let start instructions =
+  main (fun () ->
+    Ocsigen_extensions.start_initialisation ();
+    Ocsigen_extensions.set_hosts instructions)
diff --git a/src/server/ocsigen_server.mli b/src/server/ocsigen_server.mli
index c57e04a9d..6be7709a6 100644
--- a/src/server/ocsigen_server.mli
+++ b/src/server/ocsigen_server.mli
@@ -26,38 +26,39 @@ val reload : ?file:string -> unit -> unit
     [?file] may be used to read the configuration from another
     file. *)
 
-val start : ?config:Xml.xml list list -> unit -> unit
-(** Start the server. Never returns. *)
+val exec : Xml.xml list list -> unit
+(** Start the server with a configuration file. Never returns. *)
 
-(** Use this to create an extension that can be linked statically,
-    and used without configuration file. *)
-module Site : sig
-  type t
+val start : Ocsigen_extensions.host_config list -> unit
+(** Start the server with some instructions. Never returns. *)
 
-  val create :
-     ?config_info:Ocsigen_extensions.config_info
-    -> ?id:[`Attach of t * Ocsigen_lib.Url.path | `Host of string * int option]
-    -> ?charset:Ocsigen_charset_mime.charset
-    -> unit
-    -> t
-  (** [create ?config_info ?id ?charset ()]
-  creates a subsite.
-  This is equivalent to the [<host>] or [<site>] config file options.
-  *)
+type instruction =
+  Ocsigen_extensions.virtual_hosts
+  -> Ocsigen_extensions.config_info
+  -> Ocsigen_lib.Url.path
+  -> Ocsigen_extensions.extension
 
-  val default_host : t
-  (** Defaut host. Any hostname, any port.
-      Will be used if you don not specify [?site]. *)
+val host :
+   ?re:string
+  -> ?port:int
+  -> ?default_hostname:string
+  -> ?default_httpport:int
+  -> ?default_httpsport:int
+  -> ?default_protocol_is_https:bool
+  -> ?mime_assoc:Ocsigen_charset_mime.mime_assoc
+  -> ?charset_assoc:Ocsigen_charset_mime.charset_assoc
+  -> ?default_directory_index:string list
+  -> ?list_directory_content:bool
+  -> ?follow_symlinks:[`Always | `No | `Owner_match]
+  -> ?do_not_serve_404:Ocsigen_extensions.do_not_serve
+  -> ?do_not_serve_403:Ocsigen_extensions.do_not_serve
+  -> ?uploaddir:string option
+  -> ?maxuploadfilesize:int64 option
+  -> instruction list
+  -> Ocsigen_extensions.host_config
 
-  type instruction =
-    Ocsigen_extensions.virtual_hosts
-    -> Ocsigen_extensions.config_info
-    -> Ocsigen_lib.Url.path
-    -> Ocsigen_extensions.extension
-  (** Instructions are defined by extensions, and correspond to the 
-      configuration file options defined by extensions (<staticmod/> ...)*)
-
-  val register : ?site:t -> instruction -> unit
-  (** [register ~site:s e] registers instruction [e] to be run inside site [s]. 
-      Use this if you want to create an extension yourself. *)
-end
+val site :
+   ?charset:string
+  -> Ocsigen_lib.Url.path
+  -> instruction list
+  -> instruction