diff --git a/etherlink/bin_node/lib_dev/durable_storage.ml b/etherlink/bin_node/lib_dev/durable_storage.ml
index 0409574ae0be616fb7d364d7629986f058b0daa6..484ecc53212dc044ce04410e053dd0cb834862a2 100644
--- a/etherlink/bin_node/lib_dev/durable_storage.ml
+++ b/etherlink/bin_node/lib_dev/durable_storage.ml
@@ -334,6 +334,22 @@ let kernel_root_hash read =
     Durable_storage_path.kernel_root_hash
     Bytes.to_string
 
+let enable_multichain read =
+  let open Lwt_result_syntax in
+  let bytes_to_bool (b : bytes) : bool =
+    if Bytes.length b <> 1 then
+      invalid_arg
+        "Expected a single byte representing the multichain feature flag"
+    else Bytes.get b 0 <> '\x00'
+  in
+  let* res_opt =
+    inspect_durable_and_decode_opt
+      read
+      Durable_storage_path.Feature_flags.multichain
+      bytes_to_bool
+  in
+  match res_opt with Some res -> return res | None -> return false
+
 let storage_at read address (Qty pos) =
   let open Lwt_result_syntax in
   let pad32left0 s =
@@ -420,6 +436,11 @@ module Make (Reader : READER) = struct
     let* read = read_with_state () in
     chain_id read
 
+  let enable_multichain () =
+    let open Lwt_result_syntax in
+    let* read = read_with_state () in
+    enable_multichain read
+
   let l2_minimum_base_fee_per_gas chain_id =
     let open Lwt_result_syntax in
     let* read = read_with_state () in
diff --git a/etherlink/bin_node/lib_dev/durable_storage_path.ml b/etherlink/bin_node/lib_dev/durable_storage_path.ml
index f3cbe1d47375e99bfb7fbdfc38fa6e6a100e6e3d..3d4e89b3c8645975e36148b3505f10014ee1be2b 100644
--- a/etherlink/bin_node/lib_dev/durable_storage_path.ml
+++ b/etherlink/bin_node/lib_dev/durable_storage_path.ml
@@ -242,3 +242,13 @@ module Chain_configuration = struct
 
   let world_state chain_id = root chain_id ^ "/world_state"
 end
+
+module Feature_flags = struct
+  let root = EVM.make "/feature_flags"
+
+  let dal = root ^ "/enable_dal"
+
+  let fa_bridge = root ^ "/enable_fa_bridge"
+
+  let multichain = root ^ "/enable_multichain"
+end
diff --git a/etherlink/bin_node/lib_dev/durable_storage_path.mli b/etherlink/bin_node/lib_dev/durable_storage_path.mli
index 70efeb8735cf3c5f11741be6a3e5a64eebfe2fda..0656130875368a9e071d6a12d905745293f715f5 100644
--- a/etherlink/bin_node/lib_dev/durable_storage_path.mli
+++ b/etherlink/bin_node/lib_dev/durable_storage_path.mli
@@ -172,3 +172,11 @@ module Chain_configuration : sig
 
   val world_state : Ethereum_types.chain_id -> path
 end
+
+module Feature_flags : sig
+  val dal : path
+
+  val fa_bridge : path
+
+  val multichain : path
+end
diff --git a/etherlink/bin_node/lib_dev/evm_ro_context.ml b/etherlink/bin_node/lib_dev/evm_ro_context.ml
index 5c27c2fcdf65fd60dd117619785968a271a007ea..4ed1e8e334827f7ca99de2e789c3022d9e97622c 100644
--- a/etherlink/bin_node/lib_dev/evm_ro_context.ml
+++ b/etherlink/bin_node/lib_dev/evm_ro_context.ml
@@ -29,6 +29,20 @@ let read state path =
   let*! res = Evm_state.inspect state path in
   return res
 
+let read_chain_family ctxt chain_id =
+  let open Lwt_result_syntax in
+  let* _, hash = Evm_store.(use ctxt.store Context_hashes.get_latest) in
+  let* evm_state = get_evm_state ctxt hash in
+  let* chain_family = Durable_storage.chain_family (read evm_state) chain_id in
+  return chain_family
+
+let read_enable_multichain ctxt =
+  let open Lwt_result_syntax in
+  let* _, hash = Evm_store.(use ctxt.store Context_hashes.get_latest) in
+  let* evm_state = get_evm_state ctxt hash in
+  let* enable_multichain = Durable_storage.enable_multichain (read evm_state) in
+  return enable_multichain
+
 let network_sanity_check ~network ctxt =
   let open Lwt_result_syntax in
   let expected_smart_rollup_address = Constants.rollup_address network in
diff --git a/etherlink/bin_node/lib_dev/evm_ro_context.mli b/etherlink/bin_node/lib_dev/evm_ro_context.mli
index e99ce9a08b7d4a9aa3fc63cb5321363934c34862..a0071ff3787b37badb7ec0746bc76047eb088223 100644
--- a/etherlink/bin_node/lib_dev/evm_ro_context.mli
+++ b/etherlink/bin_node/lib_dev/evm_ro_context.mli
@@ -33,6 +33,11 @@ val load :
   Configuration.t ->
   t tzresult Lwt.t
 
+val read_chain_family :
+  t -> Ethereum_types.chain_id -> Ethereum_types.chain_family tzresult Lwt.t
+
+val read_enable_multichain : t -> bool tzresult Lwt.t
+
 (** [preload_known_kernels ctxt] uses [ctxt] to preload every kernel known to
     the node in the Fast Execution kernel cache. *)
 val preload_known_kernels : t -> unit tzresult Lwt.t
diff --git a/etherlink/bin_node/lib_dev/observer.ml b/etherlink/bin_node/lib_dev/observer.ml
index aabe9e19725171df8c9e066040ca22f9b1f985ae..57b4f00b470621c362320e8b92a7dfc23a492528 100644
--- a/etherlink/bin_node/lib_dev/observer.ml
+++ b/etherlink/bin_node/lib_dev/observer.ml
@@ -237,8 +237,22 @@ let main ?network ?kernel_path ~data_dir ~(config : Configuration.t) ~no_sync
     ~tx_pool_size_info:Tx_pool.size_info
     ~smart_rollup_address ;
 
+  let* chain_family =
+    match config.experimental_features.l2_chains with
+    | None -> return EVM
+    | Some [l2_chain] ->
+        let* family =
+          Evm_ro_context.read_chain_family ro_ctxt l2_chain.chain_id
+        in
+        return family
+    | _ -> failwith "Too many L2 chains for observer"
+  in
+
+  let* enable_multichain = Evm_ro_context.read_enable_multichain ro_ctxt in
+
   let* finalizer_public_server =
     Rpc_server.start_public_server
+      ~_chain_family:chain_family
       ~evm_services:
         Evm_ro_context.(evm_services_methods ro_ctxt time_between_blocks)
       ~data_dir
diff --git a/etherlink/bin_node/lib_dev/proxy.ml b/etherlink/bin_node/lib_dev/proxy.ml
index 3cf1cb90221e840b983a826033eea72bafd9663c..cdf8e09a27add66f1073cb0899a3721eb0fe09ab 100644
--- a/etherlink/bin_node/lib_dev/proxy.ml
+++ b/etherlink/bin_node/lib_dev/proxy.ml
@@ -96,6 +96,16 @@ let main
       ~rollup_node_endpoint
       ()
   in
+  let* _chain_family =
+    match config.experimental_features.l2_chains with
+    | None -> return Ethereum_types.EVM
+    | Some [l2_chain] ->
+        let* family = Rollup_node_rpc.chain_family l2_chain.chain_id in
+        return family
+    | _ -> failwith "Too many L2 chains for proxy"
+  in
+  let* _enable_multichain = Rollup_node_rpc.enable_multichain () in
+
   let* server_finalizer =
     Rpc_server.start_public_server
       validation_mode
diff --git a/etherlink/bin_node/lib_dev/rpc.ml b/etherlink/bin_node/lib_dev/rpc.ml
index 36b9c8ef95c0c66ae0987a8bbdb0bb808e5dec3f..5d5fddfeb28aa396b0b376d5ee5bf69f648b20e6 100644
--- a/etherlink/bin_node/lib_dev/rpc.ml
+++ b/etherlink/bin_node/lib_dev/rpc.ml
@@ -122,6 +122,17 @@ let main ~data_dir ~evm_node_endpoint ?evm_node_private_endpoint
     }
   in
 
+  let* _chain_family =
+    match config.experimental_features.l2_chains with
+    | None -> return Ethereum_types.EVM
+    | Some [l2_chain] ->
+        let* family = Evm_ro_context.read_chain_family ctxt l2_chain.chain_id in
+        return family (* This ensures the result is an option inside Lwt *)
+    | _ -> failwith "Too many L2 chains for rpc"
+  in
+
+  let* _enable_multichain = Evm_ro_context.read_enable_multichain ctxt in
+
   let* server_public_finalizer =
     Rpc_server.start_public_server
       ~delegate_health_check_to:evm_node_endpoint
diff --git a/etherlink/bin_node/lib_dev/rpc_server.ml b/etherlink/bin_node/lib_dev/rpc_server.ml
index f76c806dffd63994de29c573a262156af4dcecfe..379ce945628dbd826942096401b9d597a15aa598 100644
--- a/etherlink/bin_node/lib_dev/rpc_server.ml
+++ b/etherlink/bin_node/lib_dev/rpc_server.ml
@@ -124,8 +124,9 @@ let monitor_performances ~data_dir =
   in
   Lwt.dont_wait aux (Fun.const ())
 
-let start_public_server ?delegate_health_check_to ?evm_services ?data_dir
-    validation (config : Configuration.t) ctxt =
+let start_public_server ~_rpc_server_family ~_enable_multichain
+    ?delegate_health_check_to ?evm_services ?data_dir validation
+    (config : Configuration.t) ctxt =
   let open Lwt_result_syntax in
   let*! can_start_performance_metrics =
     Octez_performance_metrics.supports_performance_metrics ()
diff --git a/etherlink/bin_node/lib_dev/rpc_types.ml b/etherlink/bin_node/lib_dev/rpc_types.ml
new file mode 100644
index 0000000000000000000000000000000000000000..d9abf37df45bc29057452c6206ca986403e3f657
--- /dev/null
+++ b/etherlink/bin_node/lib_dev/rpc_types.ml
@@ -0,0 +1,21 @@
+(*****************************************************************************)
+(*                                                                           *)
+(* SPDX-License-Identifier: MIT                                              *)
+(* Copyright (c) 2025 Nomadic Labs <contact@nomadic-labs.com>                *)
+(*                                                                           *)
+(*****************************************************************************)
+
+(* The set of supported RPCs depends on the mode.
+   For the sequencer, only very few JSON RPCs need to be supported.
+   For the observer, proxy, and RPC modes, we assume that a single
+   chain is followed even when the multichain feature is activated
+   and the set of supported RPCs depends on the chain family. *)
+
+(* The set of supported RPCs depends on the mode.
+   For the sequencer, only very few JSON RPCs need to be supported.
+   For the observer, proxy, and RPC modes, we assume that a single
+   chain is followed even when the multichain feature is activated
+   and the set of supported RPCs depends on the chain family. *)
+type rpc_server_family =
+  | Sequencer_rpc_server
+  | Single_chain_node_rpc_server of Ethereum_types.chain_family
diff --git a/etherlink/bin_node/lib_dev/sequencer.ml b/etherlink/bin_node/lib_dev/sequencer.ml
index 62da7d22ea27ba7554bea009d9cdcffab62f7b59..92d05991db1242632b026b0174aa13fefbcaf84f 100644
--- a/etherlink/bin_node/lib_dev/sequencer.ml
+++ b/etherlink/bin_node/lib_dev/sequencer.ml
@@ -189,6 +189,7 @@ let main ~data_dir ?(genesis_timestamp = Misc.now ()) ~cctxt
       in
       return_unit
   in
+  let* _enable_multichain = Evm_ro_context.read_enable_multichain ro_ctxt in
   let* finalizer_public_server =
     Rpc_server.start_public_server
       ~evm_services:
diff --git a/etherlink/bin_node/lib_dev/services_backend_sig.ml b/etherlink/bin_node/lib_dev/services_backend_sig.ml
index a69faca1e48bf29419c059b26aa4df4788b59589..e24c60d5b9e059ed751de9c129863d2bbd1c6a87 100644
--- a/etherlink/bin_node/lib_dev/services_backend_sig.ml
+++ b/etherlink/bin_node/lib_dev/services_backend_sig.ml
@@ -99,6 +99,11 @@ module type S = sig
       or the zero address. *)
   val coinbase : unit -> Ethereum_types.address tzresult Lwt.t
 
+  (** enable_multichain () returns the value of the enable_multichain
+      this method targets proxy nodes that do not have direct access
+      to the durable storage. *)
+  val enable_multichain : unit -> bool tzresult Lwt.t
+
   include Tracer_sig.S
 end