diff --git a/src/lib_dac_node/RPC_server.ml b/src/lib_dac_node/RPC_server.ml
index 9aa77288cc26608aeebaf852a413d87e21dc2fee..2e9f1602afd6ff803e4b707acb366475f24b2e7a 100644
--- a/src/lib_dac_node/RPC_server.ml
+++ b/src/lib_dac_node/RPC_server.ml
@@ -90,7 +90,11 @@ let handle_post_store_preimage dac_plugin cctxt dac_sk_uris page_store
           data
   in
   let* signature, witnesses =
-    Signature_manager.sign_root_hash dac_plugin cctxt dac_sk_uris root_hash
+    Signature_manager.Legacy.sign_root_hash
+      dac_plugin
+      cctxt
+      dac_sk_uris
+      root_hash
   in
   let raw_root_hash = Dac_plugin.hash_to_raw root_hash in
   let*! external_message =
@@ -134,10 +138,10 @@ let handle_monitor_root_hashes hash_streamer =
   let* () = Event.(emit handle_new_subscription_to_hash_streamer ()) in
   Tezos_rpc.Answer.return_stream {next; shutdown}
 
-let handle_get_certificate dac_plugin ctx raw_root_hash =
+let handle_get_certificate dac_plugin node_store raw_root_hash =
   let open Lwt_result_syntax in
   let*? root_hash = Dac_plugin.raw_to_hash dac_plugin raw_root_hash in
-  let node_store = Node_context.get_node_store ctx Store_sigs.Read_only in
+
   let+ value_opt = Store.Certificate_store.find node_store root_hash in
   Option.map
     (fun Store.{aggregate_signature; witnesses} ->
@@ -192,34 +196,19 @@ let register_monitor_root_hashes hash_streamer dir =
     Monitor_services.S.root_hashes
     (fun () () () -> handle_monitor_root_hashes hash_streamer)
 
-let register_put_dac_member_signature ctx cctxt =
-  add_service
-    Tezos_rpc.Directory.register0
-    RPC_services.put_dac_member_signature
-    (fun () dac_member_signature ->
-      Signature_manager.Coordinator.handle_put_dac_member_signature
-        ctx
-        cctxt
-        dac_member_signature)
-
-let register_get_certificate ctx dac_plugin =
+let register_get_certificate node_store dac_plugin =
   add_service
     Tezos_rpc.Directory.register1
     RPC_services.get_certificate
-    (fun root_hash () () -> handle_get_certificate dac_plugin ctx root_hash)
+    (fun root_hash () () ->
+      handle_get_certificate dac_plugin node_store root_hash)
 
-let register_get_missing_page ctx dac_plugin =
-  match Node_context.mode ctx with
-  | Legacy _ | Observer _ ->
-      add_service
-        Tezos_rpc.Directory.register1
-        RPC_services.get_missing_page
-        (fun root_hash () () ->
-          let open Lwt_result_syntax in
-          let page_store = Node_context.get_page_store ctx in
-          let*? cctxt = Node_context.get_coordinator_client ctx in
-          handle_get_missing_page cctxt page_store dac_plugin root_hash)
-  | Coordinator _ | Committee_member _ -> Fun.id
+let register_get_missing_page dac_plugin page_store cctxt =
+  add_service
+    Tezos_rpc.Directory.register1
+    RPC_services.get_missing_page
+    (fun root_hash () () ->
+      handle_get_missing_page cctxt page_store dac_plugin root_hash)
 
 module Coordinator = struct
   let handle_post_preimage dac_plugin page_store hash_streamer payload =
@@ -238,7 +227,7 @@ module Coordinator = struct
     in
     return @@ Dac_plugin.hash_to_raw root_hash
 
-  let handle_monitor_certificate dac_plugin ro_store certificate_streamers
+  let handle_monitor_certificate dac_plugin ro_node_store certificate_streamers
       raw_root_hash committee_members =
     let open Lwt_result_syntax in
     let*? stream, stopper =
@@ -255,7 +244,7 @@ module Coordinator = struct
        a certificate is returned even in the case that no updates to the
        certificate happen for a long time. *)
     let*! current_certificate_store_value_res =
-      Store.Certificate_store.find ro_store root_hash
+      Store.Certificate_store.find ro_node_store root_hash
     in
     match current_certificate_store_value_res with
     | Ok current_certificate_store_value ->
@@ -291,8 +280,8 @@ module Coordinator = struct
         return (next, shutdown)
     | Error e -> fail e
 
-  let register_monitor_certificate dac_plugin ro_store certificate_streamers
-      committee_members dir =
+  let register_monitor_certificate dac_plugin ro_node_store
+      certificate_streamers committee_members dir =
     Tezos_rpc.Directory.gen_register
       dir
       Monitor_services.S.certificate
@@ -301,7 +290,7 @@ module Coordinator = struct
         let*! handler =
           handle_monitor_certificate
             dac_plugin
-            ro_store
+            ro_node_store
             certificate_streamers
             root_hash
             committee_members
@@ -310,77 +299,98 @@ module Coordinator = struct
         | Ok (next, shutdown) -> Tezos_rpc.Answer.return_stream {next; shutdown}
         | Error e -> Tezos_rpc.Answer.fail e)
 
-  let register_coordinator_post_preimage dac_plugin hash_streamer page_store =
+  let register_post_preimage dac_plugin hash_streamer page_store =
     add_service
       Tezos_rpc.Directory.register0
       RPC_services.Coordinator.post_preimage
       (fun () payload ->
         handle_post_preimage dac_plugin page_store hash_streamer payload)
 
-  let dynamic_rpc_dir dac_plugin (node_ctxt : Node_context.t) =
-    let modal_node_ctxt =
-      match Node_context.mode node_ctxt with
-      | Coordinator modal_node_ctxt -> modal_node_ctxt
-      (* We only pass [Node_context.t] values whose mode is [Coordinator _] to
-         this function. *)
-      | _ -> assert false
-    in
+  let register_put_dac_member_signature ctx dac_plugin rw_node_store page_store
+      cctxt =
+    add_service
+      Tezos_rpc.Directory.register0
+      RPC_services.put_dac_member_signature
+      (fun () dac_member_signature ->
+        Signature_manager.Coordinator.handle_put_dac_member_signature
+          ctx
+          dac_plugin
+          rw_node_store
+          page_store
+          cctxt
+          dac_member_signature)
 
+  let dynamic_rpc_dir dac_plugin rw_store page_store cctxt coordinator_node_ctxt
+      =
     let hash_streamer =
-      modal_node_ctxt.Node_context.Coordinator.hash_streamer
+      coordinator_node_ctxt.Node_context.Coordinator.hash_streamer
     in
     let public_keys_opt =
-      Node_context.Coordinator.public_keys_opt modal_node_ctxt
+      Node_context.Coordinator.public_keys_opt coordinator_node_ctxt
     in
-    let page_store = Node_context.get_page_store node_ctxt in
-    let cctxt = Node_context.get_tezos_node_cctxt node_ctxt in
-    let certificate_streamers = modal_node_ctxt.certificate_streamers in
-    let ro_store = Node_context.get_node_store node_ctxt Store_sigs.Read_only in
-    let committee_members = modal_node_ctxt.committee_members in
+    let certificate_streamers = coordinator_node_ctxt.certificate_streamers in
+    let committee_members = coordinator_node_ctxt.committee_members in
     Tezos_rpc.Directory.empty
-    |> register_coordinator_post_preimage dac_plugin hash_streamer page_store
+    |> register_post_preimage dac_plugin hash_streamer page_store
     |> register_get_verify_signature dac_plugin public_keys_opt
     |> register_get_preimage dac_plugin page_store
     |> register_monitor_root_hashes hash_streamer
     |> register_monitor_certificate
          dac_plugin
-         ro_store
+         rw_store
          certificate_streamers
          committee_members
-    |> register_put_dac_member_signature node_ctxt cctxt
-    |> register_get_certificate node_ctxt dac_plugin
+    |> register_put_dac_member_signature
+         coordinator_node_ctxt
+         dac_plugin
+         rw_store
+         page_store
+         cctxt
+    |> register_get_certificate rw_store dac_plugin
 end
 
 module Committee_member = struct
-  let dynamic_rpc_dir dac_plugin (node_ctxt : Node_context.t) =
-    let page_store = Node_context.get_page_store node_ctxt in
+  let dynamic_rpc_dir dac_plugin page_store =
     Tezos_rpc.Directory.empty |> register_get_preimage dac_plugin page_store
 end
 
 module Observer = struct
-  let dynamic_rpc_dir dac_plugin (node_ctxt : Node_context.t) =
-    let page_store = Node_context.get_page_store node_ctxt in
+  let dynamic_rpc_dir dac_plugin coordinator_cctxt page_store =
     Tezos_rpc.Directory.empty
     |> register_get_preimage dac_plugin page_store
-    |> register_get_missing_page node_ctxt dac_plugin
+    |> register_get_missing_page dac_plugin page_store coordinator_cctxt
 end
 
 module Legacy = struct
-  let dynamic_rpc_dir dac_plugin (node_ctxt : Node_context.t) =
-    let modal_node_ctxt =
-      match Node_context.mode node_ctxt with
-      | Legacy modal_node_ctxt -> modal_node_ctxt
-      (* We only pass [Node_context.t] values whose mode is [Coordinator _] to
-         this function. *)
-      | _ -> assert false
+  let register_put_dac_member_signature ctx dac_plugin rw_node_store page_store
+      cctxt =
+    add_service
+      Tezos_rpc.Directory.register0
+      RPC_services.put_dac_member_signature
+      (fun () dac_member_signature ->
+        Signature_manager.Legacy.handle_put_dac_member_signature
+          ctx
+          dac_plugin
+          rw_node_store
+          page_store
+          cctxt
+          dac_member_signature)
+
+  let dynamic_rpc_dir dac_plugin rw_store page_store cctxt legacy_node_ctxt =
+    let hash_streamer = legacy_node_ctxt.Node_context.Legacy.hash_streamer in
+    let public_keys_opt =
+      Node_context.Legacy.public_keys_opt legacy_node_ctxt
     in
-    let hash_streamer = modal_node_ctxt.Node_context.Legacy.hash_streamer in
-    let public_keys_opt = Node_context.Legacy.public_keys_opt modal_node_ctxt in
     let secret_key_uris_opt =
-      Node_context.Legacy.secret_key_uris_opt modal_node_ctxt
+      Node_context.Legacy.secret_key_uris_opt legacy_node_ctxt
+    in
+    let register_get_missing_page =
+      match legacy_node_ctxt.coordinator_cctxt with
+      | None -> fun dir -> dir
+      | Some cctxt ->
+          fun dir ->
+            dir |> register_get_missing_page dac_plugin page_store cctxt
     in
-    let page_store = Node_context.get_page_store node_ctxt in
-    let cctxt = Node_context.get_tezos_node_cctxt node_ctxt in
     Tezos_rpc.Directory.empty
     |> register_post_store_preimage
          dac_plugin
@@ -391,20 +401,41 @@ module Legacy = struct
     |> register_get_verify_signature dac_plugin public_keys_opt
     |> register_get_preimage dac_plugin page_store
     |> register_monitor_root_hashes hash_streamer
-    |> register_put_dac_member_signature node_ctxt cctxt
-    |> register_get_certificate node_ctxt dac_plugin
-    |> register_get_missing_page node_ctxt dac_plugin
+    |> register_put_dac_member_signature
+         legacy_node_ctxt
+         dac_plugin
+         rw_store
+         page_store
+         cctxt
+    |> register_get_certificate rw_store dac_plugin
+    |> register_get_missing_page
 end
 
 let start ~rpc_address ~rpc_port node_ctxt =
   let open Lwt_syntax in
+  let rw_store = Node_context.get_node_store node_ctxt Store_sigs.Read_write in
+  let page_store = Node_context.get_page_store node_ctxt in
+  let cctxt = Node_context.get_tezos_node_cctxt node_ctxt in
   let register_dynamic_rpc dac_plugin =
-    match Node_context.mode node_ctxt with
-    | Coordinator _ -> Coordinator.dynamic_rpc_dir dac_plugin node_ctxt
-    | Committee_member _ ->
-        Committee_member.dynamic_rpc_dir dac_plugin node_ctxt
-    | Observer _ -> Observer.dynamic_rpc_dir dac_plugin node_ctxt
-    | Legacy _ -> Legacy.dynamic_rpc_dir dac_plugin node_ctxt
+    match Node_context.get_mode node_ctxt with
+    | Coordinator coordinator_node_ctxt ->
+        Coordinator.dynamic_rpc_dir
+          dac_plugin
+          rw_store
+          page_store
+          cctxt
+          coordinator_node_ctxt
+    | Committee_member _committee_member_node_ctxt ->
+        Committee_member.dynamic_rpc_dir dac_plugin page_store
+    | Observer {coordinator_cctxt; _} ->
+        Observer.dynamic_rpc_dir dac_plugin coordinator_cctxt page_store
+    | Legacy legacy_node_ctxt ->
+        Legacy.dynamic_rpc_dir
+          dac_plugin
+          rw_store
+          page_store
+          cctxt
+          legacy_node_ctxt
   in
   let dir =
     Tezos_rpc.Directory.register_dynamic_directory
diff --git a/src/lib_dac_node/configuration.ml b/src/lib_dac_node/configuration.ml
index 6c034400a5f96c87740ab91958de3d92e3409a96..5712cd8c7c4b855e2727a854b33fca4a38e12c0d 100644
--- a/src/lib_dac_node/configuration.ml
+++ b/src/lib_dac_node/configuration.ml
@@ -68,6 +68,8 @@ module Coordinator = struct
               (list Tezos_crypto.Aggregate_signature.Public_key_hash.encoding))))
 
   let committee_members_addresses t = t.committee_members_addresses
+
+  let name = "Coordinator"
 end
 
 module Committee_member = struct
@@ -93,6 +95,8 @@ module Committee_member = struct
            (req
               "address"
               Tezos_crypto.Aggregate_signature.Public_key_hash.encoding)))
+
+  let name = "Committee_member"
 end
 
 module Observer = struct
@@ -111,6 +115,8 @@ module Observer = struct
         (obj2
            (req "coordinator_rpc_address" string)
            (req "coordinator_rpc_port" uint16)))
+
+  let name = "Observer"
 end
 
 module Legacy = struct
@@ -180,6 +186,8 @@ module Legacy = struct
            (opt
               "committee_member_address_opt"
               Tezos_crypto.Aggregate_signature.Public_key_hash.encoding)))
+
+  let name = "Legacy"
 end
 
 type mode =
@@ -222,6 +230,13 @@ type t = {
           DAC. *)
 }
 
+let mode_name t =
+  match t.mode with
+  | Coordinator _ -> Coordinator.name
+  | Committee_member _ -> Committee_member.name
+  | Observer _ -> Observer.name
+  | Legacy _ -> Legacy.name
+
 let make ~data_dir ~reveal_data_dir rpc_address rpc_port mode =
   {data_dir; reveal_data_dir; rpc_address; rpc_port; mode}
 
@@ -240,26 +255,26 @@ let mode_encoding =
     union
       [
         case
-          ~title:"Coordinator"
-          (Tag (0, "coordinator"))
+          ~title:Coordinator.name
+          (Tag (0, Coordinator.name))
           Coordinator.encoding
           (function Coordinator t -> Some t | _ -> None)
           (fun t -> Coordinator t);
         case
-          ~title:"Committee_member"
-          (Tag (1, "committee_member"))
+          ~title:Committee_member.name
+          (Tag (1, Committee_member.name))
           Committee_member.encoding
           (function Committee_member t -> Some t | _ -> None)
           (fun t -> Committee_member t);
         case
-          ~title:"Observer"
-          (Tag (2, "observer"))
+          ~title:Observer.name
+          (Tag (2, Observer.name))
           Observer.encoding
           (function Observer t -> Some t | _ -> None)
           (fun t -> Observer t);
         case
-          ~title:"Legacy"
-          (Tag (3, "legacy"))
+          ~title:Legacy.name
+          (Tag (3, Legacy.name))
           Legacy.encoding
           (function Legacy t -> Some t | _ -> None)
           (fun t -> Legacy t);
diff --git a/src/lib_dac_node/configuration.mli b/src/lib_dac_node/configuration.mli
index 172b9fe44f8c01234c6b8918eb26734094a88fd8..abd344f29e2c2facf99183ad0482249ca72a66a4 100644
--- a/src/lib_dac_node/configuration.mli
+++ b/src/lib_dac_node/configuration.mli
@@ -108,6 +108,10 @@ type t = private {
           DAC. *)
 }
 
+(** [mode_name t] returns a string representation of the operating mode
+    for the configuration [t]. *)
+val mode_name : t -> string
+
 (** [make_coordinator threshold dac_members_addresses] creates a new coordinator
     configuration mode using the given [threshold] and [dac_members_addresses].
 *)
diff --git a/src/lib_dac_node/daemon.ml b/src/lib_dac_node/daemon.ml
index 1589861fd3e4afeb95674c8ec02da3c4b5558107..8ba9dc68a44f4317afca9192e1a7f419fe6971d1 100644
--- a/src/lib_dac_node/daemon.ml
+++ b/src/lib_dac_node/daemon.ml
@@ -53,38 +53,6 @@ let daemonize handlers =
    return_unit)
   |> lwt_map_error (List.fold_left (fun acc errs -> errs @ acc) [])
 
-let get_all_committee_members_keys pkhs ~threshold wallet_cctxt =
-  let open Lwt_result_syntax in
-  let* wallet_accounts =
-    List.map_es
-      (fun pkh ->
-        Wallet_account.Legacy.of_committee_member_address pkh wallet_cctxt)
-      pkhs
-  in
-  let*! valid_wallet_accounts =
-    List.filter_s
-      (fun Wallet_account.Legacy.{public_key_hash; secret_key_uri_opt; _} ->
-        if Option.is_some secret_key_uri_opt then Lwt.return true
-        else
-          let*! () =
-            Event.(emit committee_member_cannot_sign public_key_hash)
-          in
-          Lwt.return false)
-      wallet_accounts
-  in
-  let recovered_keys = List.length valid_wallet_accounts in
-  let*! () =
-    (* We emit a warning if the threshold of dac accounts needed to sign a
-       root page hash is not reached. We also emit a warning for each DAC
-       account whose secret key URI was not recovered.
-       We do not stop the dac node at this stage.
-    *)
-    if recovered_keys < threshold then
-      Event.(emit dac_threshold_not_reached (recovered_keys, threshold))
-    else Event.(emit dac_is_ready) ()
-  in
-  return wallet_accounts
-
 (* FIXME: https://gitlab.com/tezos/tezos/-/issues/3605
    Improve general architecture, handle L1 disconnection etc
 *)
@@ -96,6 +64,8 @@ let run ~data_dir cctxt =
        config) =
     Configuration.load ~data_dir
   in
+  let operating_mode_string = Configuration.mode_name config in
+  let*! () = Event.(emit operating_mode operating_mode_string) in
   let* () = Page_store.ensure_reveal_data_dir_exists reveal_data_dir in
   let* ctxt = Node_context.init config cctxt in
   (* TODO: https://gitlab.com/tezos/tezos/-/issues/4725
diff --git a/src/lib_dac_node/event.ml b/src/lib_dac_node/event.ml
index 081d816c84c4cd7b35d14988642903fa69f9c719..943ef6006b1920f027e41ff020d407a60dfaaa54 100644
--- a/src/lib_dac_node/event.ml
+++ b/src/lib_dac_node/event.ml
@@ -52,6 +52,14 @@ let store_is_ready =
     ~level:Notice
     ()
 
+let operating_mode =
+  declare_1
+    ~section
+    ~name:"dac_node_running_mode"
+    ~msg:"The DAC node is running in mode {mode}"
+    ~level:Notice
+    ("mode", Data_encoding.string)
+
 let rpc_server_is_ready =
   declare_2
     ~section
diff --git a/src/lib_dac_node/handler.ml b/src/lib_dac_node/handler.ml
index 05e3869e2bec0485407cabb0893ecec6252141a0..472fea25d6afc0d9fde87192f92224ba898a41a9 100644
--- a/src/lib_dac_node/handler.ml
+++ b/src/lib_dac_node/handler.ml
@@ -362,7 +362,7 @@ let handlers node_ctxt =
   let*? plugin = Node_context.get_dac_plugin node_ctxt in
   let page_store = Node_context.get_page_store node_ctxt in
   let wallet_cctxt = Node_context.get_tezos_node_cctxt node_ctxt in
-  match Node_context.mode node_ctxt with
+  match Node_context.get_mode node_ctxt with
   | Coordinator _ -> return [new_head node_ctxt]
   | Committee_member ctxt ->
       return
diff --git a/src/lib_dac_node/node_context.ml b/src/lib_dac_node/node_context.ml
index 47416656e5b0b23f10adaa8b6f111d5c28dee9ce..15a2306d9c6d5bd4d83667f39cbb9355c0375e2c 100644
--- a/src/lib_dac_node/node_context.ml
+++ b/src/lib_dac_node/node_context.ml
@@ -63,6 +63,11 @@ module Coordinator = struct
     List.map
       (fun Wallet_account.Coordinator.{public_key_opt; _} -> public_key_opt)
       t.committee_members
+
+  let committee_members t =
+    List.map
+      (fun Wallet_account.Coordinator.{public_key_hash; _} -> public_key_hash)
+      t.committee_members
 end
 
 module Committee_member = struct
@@ -196,6 +201,11 @@ module Legacy = struct
     List.map
       (fun Wallet_account.Legacy.{secret_key_uri_opt; _} -> secret_key_uri_opt)
       t.committee_members
+
+  let committee_members t =
+    List.map
+      (fun Wallet_account.Legacy.{public_key_hash; _} -> public_key_hash)
+      t.committee_members
 end
 
 type mode =
@@ -251,7 +261,7 @@ let init config cctxt =
     mode;
   }
 
-let mode node_ctxt = node_ctxt.mode
+let get_mode node_ctxt = node_ctxt.mode
 
 let set_ready ctxt dac_plugin =
   match ctxt.status with
@@ -263,10 +273,7 @@ let set_ready ctxt dac_plugin =
       ctxt.status <- Ready {dac_plugin}
   | Ready _ -> raise Status_already_ready
 
-type error +=
-  | Node_not_ready
-  | Invalid_operation_for_mode of {mode : string; operation : string}
-  | Coordinator_client_not_defined_in_config
+type error += Node_not_ready
 
 let () =
   register_error_kind
@@ -280,39 +287,7 @@ let () =
         "DAC node is starting. It's not ready to respond to RPCs.")
     Data_encoding.(unit)
     (function Node_not_ready -> Some () | _ -> None)
-    (fun () -> Node_not_ready) ;
-  register_error_kind
-    `Permanent
-    ~id:"dac_unexpected_mode"
-    ~title:"Invalid operation for the current mode of Dac node."
-    ~description:
-      "An operation was called that it not supported by the current Dac node."
-    ~pp:(fun ppf (mode, operation) ->
-      Format.fprintf
-        ppf
-        "An operation was called that it not supported by the current Dac \
-         node. Mode: %s; Unsupported_operation: %s"
-        mode
-        operation)
-    Data_encoding.(
-      obj2 (req "mode" (string' Plain)) (req "operation" (string' Plain)))
-    (function
-      | Invalid_operation_for_mode {mode; operation} -> Some (mode, operation)
-      | _ -> None)
-    (fun (mode, operation) -> Invalid_operation_for_mode {mode; operation}) ;
-  register_error_kind
-    `Permanent
-    ~id:"dac_coordinator_client_not_defined_in_config"
-    ~title:"Coordinator client was not defined in config."
-    ~description:
-      "Coordinator client configuration was expected but not defined."
-    ~pp:(fun ppf () ->
-      Format.fprintf
-        ppf
-        "Coordinator client configuration was expected but not defined.")
-    Data_encoding.unit
-    (function Coordinator_client_not_defined_in_config -> Some () | _ -> None)
-    (fun () -> Coordinator_client_not_defined_in_config)
+    (fun () -> Node_not_ready)
 
 let get_ready ctxt =
   let open Result_syntax in
@@ -337,31 +312,3 @@ let get_node_store (type a) ctxt (access_mode : a Store_sigs.mode) :
   match access_mode with
   | Store_sigs.Read_only -> Store.Irmin_store.readonly ctxt.node_store
   | Store_sigs.Read_write -> ctxt.node_store
-
-let get_committee_members ctxt =
-  let open Result_syntax in
-  match ctxt.mode with
-  | Legacy legacy ->
-      Ok
-        (List.map
-           (fun Wallet_account.Legacy.{public_key_hash; _} -> public_key_hash)
-           legacy.committee_members)
-  | Coordinator coordinator ->
-      Ok
-        ((List.map (fun Wallet_account.Coordinator.{public_key_hash; _} ->
-              public_key_hash))
-           coordinator.committee_members)
-  | Observer _ ->
-      tzfail
-      @@ Invalid_operation_for_mode
-           {mode = "observer"; operation = "get_committee_members"}
-  | Committee_member _ ->
-      tzfail
-      @@ Invalid_operation_for_mode
-           {mode = "dac_member"; operation = "get_committee_members"}
-
-let get_coordinator_client ctxt =
-  match ctxt.mode with
-  | Observer observer_ctxt -> Ok observer_ctxt.coordinator_cctxt
-  | Legacy {coordinator_cctxt = Some cctxt; _} -> Ok cctxt
-  | _ -> Result_syntax.tzfail Coordinator_client_not_defined_in_config
diff --git a/src/lib_dac_node/node_context.mli b/src/lib_dac_node/node_context.mli
index 132354bfaebc2944ddd9922608015b8cc91efadd..bcd6a697c66da7cdbe641c6c6f10fa7ede099fbf 100644
--- a/src/lib_dac_node/node_context.mli
+++ b/src/lib_dac_node/node_context.mli
@@ -50,6 +50,9 @@ module Coordinator : sig
       data availability committee of [t]. *)
   val public_keys_opt :
     t -> Tezos_crypto.Aggregate_signature.public_key option list
+
+  val committee_members :
+    t -> Tezos_crypto.Aggregate_signature.public_key_hash list
 end
 
 (** [Committee_member] defines a partial [Node_context.t] that is available
@@ -111,6 +114,9 @@ module Legacy : sig
   (** [secret_key_uris_opt] return the list of optional secret key URIs of the
       committee members of [t]. *)
   val secret_key_uris_opt : t -> Client_keys.aggregate_sk_uri option list
+
+  val committee_members :
+    t -> Tezos_crypto.Aggregate_signature.public_key_hash list
 end
 
 (** Operating mode specific fraction of a [Node_context.t] *)
@@ -156,9 +162,9 @@ val get_ready : t -> ready_ctxt tzresult
 (** [get_status ctxt] returns the dac node status. *)
 val get_status : t -> status
 
-(** [mode node_ctxt] returns the operating mode specific fraction of a
+(** [get_mode node_ctxt] returns the operating mode specific fraction of a
     [Node_context.t]. *)
-val mode : t -> mode
+val get_mode : t -> mode
 
 (** [get_tezos_node_cctxt ctxt] returns the Tezos node's client context. *)
 val get_tezos_node_cctxt : t -> Client_context.full
@@ -174,13 +180,3 @@ val get_page_store : t -> Page_store.Filesystem.t
 (** [get_node_store ctxt access_mode] returns the [Store.Irmin_store.t] with
     [access_mode] used by Dac components. *)
 val get_node_store : t -> 'a Store_sigs.mode -> 'a Store.Irmin_store.t
-
-(** [get_committee_members ctxt] returns the Dac committee public key hashes from
-    [Configuration.Legacy.dac_members_addresses] or
-    [Configuration.Coordinator.dac_members_addresses] *)
-val get_committee_members :
-  t -> Tezos_crypto.Aggregate_signature.public_key_hash list tzresult
-
-(** [get_coordinator_client ctx] returns the Coordinator client if it
-    is available. *)
-val get_coordinator_client : t -> Dac_node_client.cctxt tzresult
diff --git a/src/lib_dac_node/signature_manager.ml b/src/lib_dac_node/signature_manager.ml
index 5fef6f9aa1d2d5224b70738cf6cc774f20ab90c8..8b35e08a52993d3f5f454927db5abfc07257b83d 100644
--- a/src/lib_dac_node/signature_manager.ml
+++ b/src/lib_dac_node/signature_manager.ml
@@ -24,10 +24,17 @@
 (*                                                                           *)
 (*****************************************************************************)
 
+module Aggregate_signature = Tezos_crypto.Aggregate_signature
+
 type error +=
   | Cannot_convert_root_page_hash_to_bytes of string
   | Cannot_compute_aggregate_signature of string
   | Public_key_for_witness_not_available of int * string
+  | Public_key_is_non_committee_member of Aggregate_signature.public_key_hash
+  | Signature_verification_failed of
+      (Aggregate_signature.public_key * Aggregate_signature.t * string)
+  | Public_key_for_committee_member_not_available of
+      Aggregate_signature.public_key_hash
 
 let () =
   register_error_kind
@@ -63,14 +70,16 @@ let () =
     `Permanent
     ~id:"public_key_of_witness_not_available"
     ~title:
-      "Public key of witness dac member not available for verifying signature"
+      "Public key of witness committee member not available for verifying \
+       signature"
     ~description:
-      "Public key of witness dac member not available for verifying signature"
+      "Public key of witness committee member not available for verifying \
+       signature"
     ~pp:(fun ppf (witness_index, b58_hash) ->
       Format.fprintf
         ppf
-        "Public key of dac member %d not available for verifying signature of \
-         root page hash %s"
+        "Public key of committee member %d not available for verifying \
+         signature of root page hash %s"
         witness_index
         b58_hash)
     Data_encoding.(
@@ -78,7 +87,76 @@ let () =
     (function
       | Public_key_for_witness_not_available (index, hash) -> Some (index, hash)
       | _ -> None)
-    (fun (index, hash) -> Public_key_for_witness_not_available (index, hash))
+    (fun (index, hash) -> Public_key_for_witness_not_available (index, hash)) ;
+  register_error_kind
+    `Permanent
+    ~id:"Public_key_is_non_committee_member"
+    ~title:"Public key hash is not a committee member"
+    ~description:
+      "Public key hash is not associated with any committee member registered \
+       with this Dac coordinator."
+    ~pp:(fun ppf committee_member_pkh ->
+      Format.fprintf
+        ppf
+        "Expected public key to be an active committee member but was not: %s"
+        (Tezos_crypto.Aggregate_signature.Public_key_hash.to_short_b58check
+           committee_member_pkh))
+    Data_encoding.(
+      obj1
+        (req
+           "public_key_hash"
+           Tezos_crypto.Aggregate_signature.Public_key_hash.encoding))
+    (function
+      | Public_key_is_non_committee_member committee_member_pkh ->
+          Some committee_member_pkh
+      | _ -> None)
+    (fun committee_member_pkh ->
+      Public_key_is_non_committee_member committee_member_pkh) ;
+  register_error_kind
+    `Permanent
+    ~id:"signature_verification_failed"
+    ~title:"Signature verification failed"
+    ~description:"Signature verification failed."
+    ~pp:(fun ppf (pk, signature, root_hash) ->
+      let pk = Aggregate_signature.Public_key.to_short_b58check pk in
+      let signature = Aggregate_signature.to_short_b58check signature in
+      Format.fprintf
+        ppf
+        "Could not verify signature \"%s\" given public key \"%s\" and \
+         root_hash \"%s\": Signature verification failed."
+        pk
+        signature
+        root_hash)
+    Data_encoding.(
+      obj3
+        (req "public_key" Aggregate_signature.Public_key.encoding)
+        (req "signature" Aggregate_signature.encoding)
+        (req "root_hash" (string' Plain)))
+    (function
+      | Signature_verification_failed (pk, signature, root_hash) ->
+          Some (pk, signature, root_hash)
+      | _ -> None)
+    (function
+      | pk, signature, root_hash ->
+          Signature_verification_failed (pk, signature, root_hash)) ;
+  register_error_kind
+    `Permanent
+    ~id:"public_key_of_committee_member_not_available"
+    ~title:"Public key of committee member not available."
+    ~description:"Public key of committee member not available."
+    ~pp:(fun ppf b58_hash ->
+      Format.fprintf
+        ppf
+        "Public key of committee member %s not available."
+        b58_hash)
+    Data_encoding.(obj1 (req "hash" (string' Plain)))
+    (function
+      | Public_key_for_committee_member_not_available hash ->
+          Some (Aggregate_signature.Public_key_hash.to_b58check hash)
+      | _ -> None)
+    (fun hash ->
+      Public_key_for_committee_member_not_available
+        (Aggregate_signature.Public_key_hash.of_b58check_exn hash))
 
 let bind_es (f : 'a -> 'b option tzresult Lwt.t) v_opt =
   let open Lwt_result_syntax in
@@ -117,28 +195,6 @@ let compute_signatures_with_witnesses rev_indexed_signatures =
     ([], Z.zero)
     rev_indexed_signatures
 
-let sign_root_hash ((module Plugin) : Dac_plugin.t) cctxt dac_sk_uris root_hash
-    =
-  let open Lwt_result_syntax in
-  let bytes_to_sign =
-    Data_encoding.Binary.to_bytes_opt Plugin.encoding root_hash
-  in
-  let root_hash = Plugin.to_hex root_hash in
-  match bytes_to_sign with
-  | None -> tzfail @@ Cannot_convert_root_page_hash_to_bytes root_hash
-  | Some bytes_to_sign -> (
-      let* rev_indexed_signatures =
-        rev_collect_indexed_signatures cctxt dac_sk_uris bytes_to_sign
-      in
-      let* signatures, witnesses =
-        compute_signatures_with_witnesses rev_indexed_signatures
-      in
-      match
-        Tezos_crypto.Aggregate_signature.aggregate_signature_opt signatures
-      with
-      | None -> tzfail @@ Cannot_compute_aggregate_signature root_hash
-      | Some signature -> return @@ (signature, witnesses))
-
 let verify dac_plugin ~public_keys_opt root_page_hash signature witnesses =
   let open Lwt_result_syntax in
   let ((module Plugin) : Dac_plugin.t) = dac_plugin in
@@ -168,281 +224,218 @@ let verify dac_plugin ~public_keys_opt root_page_hash signature witnesses =
       return
       @@ Tezos_crypto.Aggregate_signature.aggregate_check pk_msg_list signature
 
-module Coordinator = struct
-  module Aggregate_signature = Tezos_crypto.Aggregate_signature
-
-  type error +=
-    | Public_key_is_non_dac_member of Aggregate_signature.public_key_hash
-    | Signature_verification_failed of
-        (Aggregate_signature.public_key * Aggregate_signature.t * string)
-    | Public_key_for_dac_member_not_available of
-        Aggregate_signature.public_key_hash
-    | Unknown_root_hash of string
+let verify_signature ((module Plugin) : Dac_plugin.t) pk signature root_hash =
+  let root_hash_bytes = Dac_plugin.hash_to_bytes root_hash in
+  fail_unless
+    (Aggregate_signature.check pk signature root_hash_bytes)
+    (Signature_verification_failed (pk, signature, Plugin.to_hex root_hash))
 
-  let () =
-    register_error_kind
-      `Permanent
-      ~id:"Public_key_is_non_dac_member"
-      ~title:"Public key hash is not a valid dac member"
-      ~description:
-        "Public key hash is not associated with any Dac member registered with \
-         this Dac coordinator."
-      ~pp:(fun ppf dac_member_pkh ->
-        Format.fprintf
-          ppf
-          "Expected public key to be an active Dac committee member but was \
-           not: %s"
-          (Tezos_crypto.Aggregate_signature.Public_key_hash.to_short_b58check
-             dac_member_pkh))
-      Data_encoding.(
-        obj1
-          (req
-             "public_key_hash"
-             Tezos_crypto.Aggregate_signature.Public_key_hash.encoding))
-      (function
-        | Public_key_is_non_dac_member dac_member_pkh -> Some dac_member_pkh
-        | _ -> None)
-      (fun dac_member_pkh -> Public_key_is_non_dac_member dac_member_pkh) ;
-    register_error_kind
-      `Permanent
-      ~id:"signature_verification_failed"
-      ~title:"Signature verification failed"
-      ~description:"Signature verification failed."
-      ~pp:(fun ppf (pk, signature, root_hash) ->
-        let pk = Aggregate_signature.Public_key.to_short_b58check pk in
-        let signature = Aggregate_signature.to_short_b58check signature in
-        Format.fprintf
-          ppf
-          "Could not verify signature \"%s\" given public key \"%s\" and \
-           root_hash \"%s\": Signature verification failed."
-          pk
-          signature
-          root_hash)
-      Data_encoding.(
-        obj3
-          (req "public_key" Aggregate_signature.Public_key.encoding)
-          (req "signature" Aggregate_signature.encoding)
-          (req "root_hash" (string' Plain)))
-      (function
-        | Signature_verification_failed (pk, signature, root_hash) ->
-            Some (pk, signature, root_hash)
-        | _ -> None)
-      (function
-        | pk, signature, root_hash ->
-            Signature_verification_failed (pk, signature, root_hash)) ;
-    register_error_kind
-      `Permanent
-      ~id:"public_key_of_dac_member_not_available"
-      ~title:"Public key of dac member not available."
-      ~description:"Public key of  dac member not available."
-      ~pp:(fun ppf b58_hash ->
-        Format.fprintf ppf "Public key of dac member %s not available." b58_hash)
-      Data_encoding.(obj1 (req "hash" (string' Plain)))
-      (function
-        | Public_key_for_dac_member_not_available hash ->
-            Some (Aggregate_signature.Public_key_hash.to_b58check hash)
-        | _ -> None)
-      (fun hash ->
-        Public_key_for_dac_member_not_available
-          (Aggregate_signature.Public_key_hash.of_b58check_exn hash)) ;
-    register_error_kind
-      `Permanent
-      ~id:"unknown_root_hash"
-      ~title:"No data associated to the provided root hash"
-      ~description:"There is no data in storage for this root hash"
-      ~pp:(fun ppf hash ->
-        Format.fprintf
-          ppf
-          "There is no data available for the root page hash %s"
-          hash)
-      Data_encoding.(obj1 (req "hash" (string' Plain)))
-      (function Unknown_root_hash hash -> Some hash | _ -> None)
-      (fun hash -> Unknown_root_hash hash)
+let add_dac_member_signature dac_plugin signature_store
+    Signature_repr.{root_hash; signer_pkh; signature} =
+  let open Lwt_result_syntax in
+  let*? root_hash = Dac_plugin.raw_to_hash dac_plugin root_hash in
+  Store.Signature_store.add
+    signature_store
+    ~primary_key:root_hash
+    ~secondary_key:signer_pkh
+    signature
 
-  let verify_signature ((module Plugin) : Dac_plugin.t) pk signature root_hash =
-    let root_hash_bytes = Dac_plugin.hash_to_bytes root_hash in
-    fail_unless
-      (Aggregate_signature.check pk signature root_hash_bytes)
-      (Signature_verification_failed (pk, signature, Plugin.to_hex root_hash))
+let rev_find_indexed_signatures node_store dac_members_pkh root_hash =
+  let open Lwt_result_syntax in
+  List.rev_mapi_es
+    (fun index dac_member_pk ->
+      let+ (signature_opt : Aggregate_signature.t option) =
+        Store.Signature_store.find
+          node_store
+          ~primary_key:root_hash
+          ~secondary_key:dac_member_pk
+      in
+      Option.map (fun signature -> (index, signature)) signature_opt)
+    dac_members_pkh
 
-  let add_dac_member_signature dac_plugin signature_store
-      Signature_repr.{root_hash; signer_pkh; signature} =
-    let open Lwt_result_syntax in
-    let*? root_hash = Dac_plugin.raw_to_hash dac_plugin root_hash in
-    Store.Signature_store.add
-      signature_store
-      ~primary_key:root_hash
-      ~secondary_key:signer_pkh
-      signature
+let update_aggregate_sig_store node_store dac_members_pk_opt root_hash =
+  let open Lwt_result_syntax in
+  let* rev_indexed_signature =
+    rev_find_indexed_signatures node_store dac_members_pk_opt root_hash
+  in
+  let* signatures, witnesses =
+    compute_signatures_with_witnesses rev_indexed_signature
+  in
+  let final_signature =
+    Tezos_crypto.Aggregate_signature.aggregate_signature_opt signatures
+  in
+  match final_signature with
+  | None ->
+      tzfail
+      @@ Cannot_compute_aggregate_signature
+           (Hex.show @@ Dac_plugin.hash_to_hex root_hash)
+  | Some aggregate_signature ->
+      let* () =
+        Store.Certificate_store.add
+          node_store
+          root_hash
+          Store.{aggregate_signature; witnesses}
+      in
+      return @@ (aggregate_signature, witnesses)
 
-  let rev_find_indexed_signatures node_store dac_members_pk root_hash =
-    let open Lwt_result_syntax in
-    List.rev_mapi_es
-      (fun index dac_member_pk ->
-        let+ (signature_opt : Aggregate_signature.t option) =
-          Store.Signature_store.find
-            node_store
-            ~primary_key:root_hash
-            ~secondary_key:dac_member_pk
-        in
-        Option.map (fun signature -> (index, signature)) signature_opt)
-      dac_members_pk
+let check_dac_member_has_signed signature_store root_hash dac_member_pkh =
+  Store.Signature_store.mem
+    signature_store
+    ~primary_key:root_hash
+    ~secondary_key:dac_member_pkh
 
-  let update_aggregate_sig_store node_store dac_members_pk_opt root_hash =
-    let open Lwt_result_syntax in
-    let* rev_indexed_signature =
-      rev_find_indexed_signatures node_store dac_members_pk_opt root_hash
-    in
-    let* signatures, witnesses =
-      compute_signatures_with_witnesses rev_indexed_signature
-    in
-    match
-      Tezos_crypto.Aggregate_signature.aggregate_signature_opt signatures
-    with
-    | None ->
-        tzfail
-        @@ Cannot_compute_aggregate_signature
-             (Hex.show @@ Dac_plugin.hash_to_hex root_hash)
-    | Some aggregate_signature ->
-        let* () =
-          Store.Certificate_store.add
-            node_store
-            root_hash
-            Store.{aggregate_signature; witnesses}
-        in
-        return @@ (aggregate_signature, witnesses)
+let check_is_dac_member dac_committee signer_pkh =
+  Option.is_some
+  @@ List.find
+       (fun pkh -> Aggregate_signature.Public_key_hash.equal signer_pkh pkh)
+       dac_committee
 
-  let check_dac_member_has_signed signature_store root_hash dac_member_pkh =
-    let open Lwt_result_syntax in
-    let* dac_member_has_signed =
-      Store.Signature_store.mem
-        signature_store
-        ~primary_key:root_hash
-        ~secondary_key:dac_member_pkh
-    in
-    return dac_member_has_signed
+let check_coordinator_knows_root_hash dac_plugin page_store root_hash =
+  let open Lwt_result_syntax in
+  let ((module Plugin) : Dac_plugin.t) = dac_plugin in
+  let*! has_payload =
+    Page_store.Filesystem.mem (module Plugin) page_store root_hash
+  in
+  match has_payload with
+  | Error _ ->
+      tzfail
+      @@ Page_store.Cannot_read_page_from_page_storage (Plugin.to_hex root_hash)
+  (* Return an HTTP 404 error when hash provided in signature is unknown *)
+  | Ok false -> raise Not_found
+  | Ok true -> return ()
 
-  let check_is_dac_member dac_committee signer_pkh =
-    Option.is_some
-    @@ List.find
-         (fun pkh -> Aggregate_signature.Public_key_hash.equal signer_pkh pkh)
-         dac_committee
+let should_update_certificate dac_plugin cctxt ro_node_store committee_members
+    Signature_repr.{signer_pkh; root_hash; signature} =
+  let open Lwt_result_syntax in
+  let ((module Plugin) : Dac_plugin.t) = dac_plugin in
+  let*? root_hash = Dac_plugin.raw_to_hash dac_plugin root_hash in
+  let* () =
+    fail_unless
+      (check_is_dac_member committee_members signer_pkh)
+      (Public_key_is_non_committee_member signer_pkh)
+  in
+  let* pub_key_opt = Wallet_cctxt_helpers.get_public_key cctxt signer_pkh in
+  let* pub_key =
+    Option.fold_f
+      ~none:(fun () ->
+        tzfail (Public_key_for_committee_member_not_available signer_pkh))
+      ~some:return
+      pub_key_opt
+  in
+  let* dac_member_has_signed =
+    check_dac_member_has_signed ro_node_store root_hash signer_pkh
+  in
+  if dac_member_has_signed then return false
+  else
+    let* () = verify_signature dac_plugin pub_key signature root_hash in
+    return true
 
-  let check_coordinator_knows_root_hash dac_plugin page_store raw_root_hash =
-    let open Lwt_result_syntax in
-    let ((module Plugin) : Dac_plugin.t) = dac_plugin in
-    let*? root_hash = Dac_plugin.raw_to_hash dac_plugin raw_root_hash in
-    let*! has_payload =
-      Page_store.Filesystem.mem (module Plugin) page_store root_hash
+let stream_certificate_update dac_plugin committee_members
+    (Certificate_repr.{root_hash; _} as certificate) certificate_streamers =
+  let open Result_syntax in
+  let* () =
+    Certificate_streamers.push
+      dac_plugin
+      certificate_streamers
+      root_hash
+      certificate
+  in
+  if
+    Certificate_repr.all_committee_members_have_signed
+      committee_members
+      certificate
+  then
+    let _ =
+      Certificate_streamers.close dac_plugin certificate_streamers root_hash
     in
-    match has_payload with
-    | Error _ ->
-        tzfail
-        @@ Page_store.Cannot_read_page_from_page_storage
-             (Plugin.to_hex root_hash)
-    (* Return an HTTP 404 error when hash provided in signature is unknown *)
-    | Ok false -> raise Not_found
-    | Ok true -> return ()
+    return ()
+  else return ()
 
-  let should_update_certificate dac_plugin cctxt ro_node_store committee_members
-      Signature_repr.{signer_pkh; root_hash; signature} =
-    let ((module Plugin) : Dac_plugin.t) = dac_plugin in
-    let open Lwt_result_syntax in
-    let*? root_hash = Dac_plugin.raw_to_hash dac_plugin root_hash in
+let handle_put_dac_member_signature dac_plugin certificate_streamers_opt
+    rw_node_store page_store cctxt committee_members committee_member_signature
+    =
+  let open Lwt_result_syntax in
+  let ((module Plugin) : Dac_plugin.t) = dac_plugin in
+  let Signature_repr.{root_hash = raw_root_hash; _} =
+    committee_member_signature
+  in
+  let*? root_hash = Dac_plugin.raw_to_hash dac_plugin raw_root_hash in
+  let* () = check_coordinator_knows_root_hash dac_plugin page_store root_hash in
+  let* should_update_certificate =
+    should_update_certificate
+      dac_plugin
+      cctxt
+      rw_node_store
+      committee_members
+      committee_member_signature
+  in
+  if should_update_certificate then
     let* () =
-      fail_unless
-        (check_is_dac_member committee_members signer_pkh)
-        (Public_key_is_non_dac_member signer_pkh)
+      add_dac_member_signature
+        dac_plugin
+        rw_node_store
+        committee_member_signature
     in
-    let* pub_key_opt = Wallet_cctxt_helpers.get_public_key cctxt signer_pkh in
-    let* pub_key =
-      Option.fold_f
-        ~none:(fun () ->
-          tzfail (Public_key_for_dac_member_not_available signer_pkh))
-        ~some:return
-        pub_key_opt
+    let* aggregate_signature, witnesses =
+      update_aggregate_sig_store rw_node_store committee_members root_hash
     in
-    let* dac_member_has_signed =
-      check_dac_member_has_signed ro_node_store root_hash signer_pkh
+    let*? () =
+      Option.iter_e
+        (stream_certificate_update
+           dac_plugin
+           committee_members
+           Certificate_repr.
+             {root_hash = raw_root_hash; aggregate_signature; witnesses})
+        certificate_streamers_opt
     in
-    if dac_member_has_signed then return false
-    else
-      let* () = verify_signature dac_plugin pub_key signature root_hash in
-      return true
+    return ()
+  else return ()
 
-  let stream_certificate_update dac_plugin committee_members
-      (Certificate_repr.{root_hash; _} as certificate) certificate_streamers =
-    let open Result_syntax in
-    let* () =
-      Certificate_streamers.push
-        dac_plugin
-        certificate_streamers
-        root_hash
-        certificate
-    in
-    if
-      Certificate_repr.all_committee_members_have_signed
-        committee_members
-        certificate
-    then
-      let _ =
-        Certificate_streamers.close dac_plugin certificate_streamers root_hash
-      in
-      return ()
-    else return ()
+module Coordinator = struct
+  let handle_put_dac_member_signature ctx dac_plugin rw_node_store page_store
+      cctxt dac_member_signature =
+    let committee_members = Node_context.Coordinator.committee_members ctx in
+    handle_put_dac_member_signature
+      dac_plugin
+      (Some ctx.certificate_streamers)
+      rw_node_store
+      page_store
+      cctxt
+      committee_members
+      dac_member_signature
+end
 
-  let handle_put_dac_member_signature ctx cctxt committee_member_signature =
+module Legacy = struct
+  let sign_root_hash ((module P) : Dac_plugin.t) cctxt dac_sk_uris root_hash =
     let open Lwt_result_syntax in
-    let* certificate_streamers_opt =
-      match Node_context.mode ctx with
-      (* TODO: https://gitlab.com/tezos/tezos/-/issues/5292
-                  Make type non optional when Legacy mode has been removed. *)
-      | Node_context.Coordinator {certificate_streamers; _} ->
-          return @@ Some certificate_streamers
-      | Legacy _ -> return None
-      | _ ->
-          (* TODO: https://gitlab.com/tezos/tezos/-/issues/5370
-             This line will never be executed as
-             [handle_put_dac_member_signature] is only invoked when the
-             DAC node is running in either coordinator or legacy mode.
-          *)
-          failwith "Operation not supported for operating mode"
-    in
-    let*? dac_plugin = Node_context.get_dac_plugin ctx in
-    let page_store = Node_context.get_page_store ctx in
-    let*? committee_members = Node_context.get_committee_members ctx in
-    let rw_node_store = Node_context.get_node_store ctx Store_sigs.Read_write in
-    let Signature_repr.{root_hash; _} = committee_member_signature in
-    let* () =
-      check_coordinator_knows_root_hash dac_plugin page_store root_hash
+    let bytes_to_sign =
+      Data_encoding.Binary.to_bytes_opt P.encoding root_hash
     in
-    let* should_update_certificate =
-      should_update_certificate
-        dac_plugin
-        cctxt
-        rw_node_store
-        committee_members
-        committee_member_signature
-    in
-    if should_update_certificate then
-      let* () =
-        add_dac_member_signature
-          dac_plugin
-          rw_node_store
-          committee_member_signature
-      in
-      let*? root_hash' = Dac_plugin.raw_to_hash dac_plugin root_hash in
-      let* aggregate_signature, witnesses =
-        update_aggregate_sig_store rw_node_store committee_members root_hash'
-      in
-      let*? () =
-        Option.iter_e
-          (stream_certificate_update
-             dac_plugin
-             committee_members
-             Certificate_repr.{root_hash; aggregate_signature; witnesses})
-          certificate_streamers_opt
-      in
-      return ()
-    else return ()
+    let root_hash = P.to_hex root_hash in
+    match bytes_to_sign with
+    | None -> tzfail @@ Cannot_convert_root_page_hash_to_bytes root_hash
+    | Some bytes_to_sign -> (
+        let* rev_indexed_signatures =
+          rev_collect_indexed_signatures cctxt dac_sk_uris bytes_to_sign
+        in
+        let* signatures, witnesses =
+          compute_signatures_with_witnesses rev_indexed_signatures
+        in
+        match
+          Tezos_crypto.Aggregate_signature.aggregate_signature_opt signatures
+        with
+        | None -> tzfail @@ Cannot_compute_aggregate_signature root_hash
+        | Some signature -> return @@ (signature, witnesses))
+
+  let handle_put_dac_member_signature ctx dac_plugin rw_node_store page_store
+      cctxt dac_member_signature =
+    let committee_members = Node_context.Legacy.committee_members ctx in
+    handle_put_dac_member_signature
+      dac_plugin
+      None
+      rw_node_store
+      page_store
+      cctxt
+      committee_members
+      dac_member_signature
 end
diff --git a/src/lib_dac_node/signature_manager.mli b/src/lib_dac_node/signature_manager.mli
index 5e9288cc2c11715843d06be1108a6228ff5429c6..9afa9f5bb76a3ace976d480fb4ab135ebb2e123b 100644
--- a/src/lib_dac_node/signature_manager.mli
+++ b/src/lib_dac_node/signature_manager.mli
@@ -29,16 +29,14 @@ type error +=
   | Cannot_convert_root_page_hash_to_bytes of string
   | Cannot_compute_aggregate_signature of string
   | Public_key_for_witness_not_available of int * string
-
-(* [sign_root_hash dac_pliugin cctx dac_sk_uris_opt root_hash] is legacy function that
-   returns an aggregate signature over [root_hash] and a bitmap of witnesses where
-   empty elements of [dac_sk_uris_opt] are 0 and non-empty elements are 1. *)
-val sign_root_hash :
-  Dac_plugin.t ->
-  #Client_context.wallet ->
-  Client_keys.aggregate_sk_uri option trace ->
-  Dac_plugin.hash ->
-  (Tezos_crypto.Aggregate_signature.signature * Z.t, tztrace) result Lwt.t
+  | Public_key_is_non_committee_member of
+      Tezos_crypto.Aggregate_signature.public_key_hash
+  | Signature_verification_failed of
+      (Tezos_crypto.Aggregate_signature.public_key
+      * Tezos_crypto.Aggregate_signature.t
+      * string)
+  | Public_key_for_committee_member_not_available of
+      Tezos_crypto.Aggregate_signature.public_key_hash
 
 (** [verify dac_plugin public_keys_opt root_hash aggregate_signature witnesses] verifies
     the [aggregate_signature] signed by the witnessed dac members. The witnessed
@@ -55,30 +53,54 @@ val verify :
 (** Module that exposes signature operations necsesary when running in
     [Configuration.Coordinator] mode.*)
 module Coordinator : sig
-  type error +=
-    | Public_key_is_non_dac_member of
-        Tezos_crypto.Aggregate_signature.public_key_hash
-    | Signature_verification_failed of
-        (Tezos_crypto.Aggregate_signature.public_key
-        * Tezos_crypto.Aggregate_signature.t
-        * string)
-    | Public_key_for_dac_member_not_available of
-        Tezos_crypto.Aggregate_signature.public_key_hash
-    | Unknown_root_hash of string
+  (** [handle_put_dac_member_signature ctx dac_plugin ro_store rw_store page_store
+      cctxt dac_member_signature] does the following procedure:
+      1. Checks that the [root_hash] provided inside [Signature_repr.t] is known. Fails if unknown
+      2. Checks that the [dac_member_signature.signer_pkh] is currently a Dac member.
+      3. Checks that the dac member has not yet signed. If already signed, then noop
+         and return.
+      4. Otherwise:
+        1. Verify the signature against the root hash and signer's public key.
+        2. Add signature to [Signature_store]
+        3. Update the aggregate signature in [Aggregate_signature_store]
+  *)
+  val handle_put_dac_member_signature :
+    Node_context.Coordinator.t ->
+    Dac_plugin.t ->
+    Store_sigs.rw Store.Irmin_store.t ->
+    Page_store.Filesystem.t ->
+    #Client_context.wallet ->
+    Signature_repr.t ->
+    unit tzresult Lwt.t
+end
+
+module Legacy : sig
+  (* [sign_root_hash dac_pliugin cctx dac_sk_uris_opt root_hash] is legacy function that
+     returns an aggregate signature over [root_hash] and a bitmap of witnesses where
+     empty elements of [dac_sk_uris_opt] are 0 and non-empty elements are 1. *)
+  val sign_root_hash :
+    Dac_plugin.t ->
+    #Client_context.wallet ->
+    Client_keys.aggregate_sk_uri option trace ->
+    Dac_plugin.hash ->
+    (Tezos_crypto.Aggregate_signature.signature * Z.t, tztrace) result Lwt.t
 
-  (** [handle_put_dac_member_signature ctxt cctxt dac_members_pkh dac_member_signature]
-      does the following procedure:
+  (** [handle_put_dac_member_signature ctx dac_plugin ro_store rw_store page_store
+      cctxt dac_member_signature] does the following procedure:
       1. Checks that the [root_hash] provided inside [Signature_repr.t] is known. Fails if unknown
-      1. Checks that the [dac_member_signature.signer_pkh] is currently a Dac member.
-      2. Checks that the dac member has not yet signed. If already signed, then noop
+      2. Checks that the [dac_member_signature.signer_pkh] is currently a Dac member.
+      3. Checks that the dac member has not yet signed. If already signed, then noop
          and return.
-      3. Otherwise:
+      4. Otherwise:
         1. Verify the signature against the root hash and signer's public key.
         2. Add signature to [Signature_store]
         3. Update the aggregate signature in [Aggregate_signature_store]
   *)
   val handle_put_dac_member_signature :
-    Node_context.t ->
+    Node_context.Legacy.t ->
+    Dac_plugin.t ->
+    Store_sigs.rw Store.Irmin_store.t ->
+    Page_store.Filesystem.t ->
     #Client_context.wallet ->
     Signature_repr.t ->
     unit tzresult Lwt.t