diff --git a/logos_delivery/api/kernel_conf.nim b/logos_delivery/api/kernel_conf.nim
new file mode 100644
index 000000000..f2604c936
--- /dev/null
+++ b/logos_delivery/api/kernel_conf.nim
@@ -0,0 +1,6 @@
+## Kernel-layer configuration type.
+
+import tools/confutils/cli_args
+export cli_args
+
+type KernelConf* = WakuNodeConf
diff --git a/logos_delivery/api/logos_delivery_interface.nim b/logos_delivery/api/logos_delivery_interface.nim
index b0d2bd975..11532384b 100644
--- a/logos_delivery/api/logos_delivery_interface.nim
+++ b/logos_delivery/api/logos_delivery_interface.nim
@@ -15,6 +15,12 @@ import ./reliable_channel_manager_interface as ireliablechannelmanager_iface
 
 export ikernel_iface, imessagingclient_iface, ireliablechannelmanager_iface
 
+import ./messaging_conf # MessagingConf
+export messaging_conf
+
+import logos_delivery/channels/channels_conf # ChannelsConf
+export channels_conf
+
 BrokerInterface(LogosDeliveryInterface):
   EventBroker:
     type ConnectionStatusChangeEvent* = object
@@ -25,7 +31,10 @@ BrokerInterface(LogosDeliveryInterface):
 
   RequestBroker:
     proc startAsClient(
-      mode: WakuMode, preset: string
+      mode: WakuMode,
+      preset: string,
+      overrides: MessagingConf,
+      channelsConf: ChannelsConf,
     ): Future[Result[MessagingClientInterface, string]] {.async.}
 
   RequestBroker:
diff --git a/logos_delivery/api/messaging_conf.nim b/logos_delivery/api/messaging_conf.nim
new file mode 100644
index 000000000..f81d91ab5
--- /dev/null
+++ b/logos_delivery/api/messaging_conf.nim
@@ -0,0 +1,90 @@
+## Messaging-layer configuration.
+
+import std/options
+import std/sequtils # mapIt
+import results
+import std/nativesockets # Port
+import std/net # IpAddress
+
+import logos_delivery/api/types # WakuMode
+import logos_delivery/api/kernel_conf # KernelConf, ConfResult, defaultWakuNodeConf, EthRpcUrl
+export kernel_conf
+
+type MessagingConf* = object
+  ## Messaging-layer configuration as an all-`Option` partial. `toKernelConf`
+  ## applies each set field to the corresponding `KernelConf` field; unset fields
+  ## leave the kernel default unchanged.
+  clusterId*: Option[uint16]
+    ## Network cluster id.
+  numShardsInCluster*: Option[uint16]
+    ## Number of shards in the cluster.
+  p2pTcpPort*: Option[Port]
+    ## TCP listening port.
+  discv5UdpPort*: Option[Port]
+    ## discv5 UDP port.
+  listenIpv4*: Option[IpAddress]
+    ## Inbound bind address.
+  maxMessageSize*: Option[string]
+    ## Maximum accepted message size (e.g. "150 KiB").
+  entryNodes*: Option[seq[string]]
+    ## Bootstrap / connectivity nodes (enrtree or multiaddr).
+  ethRpcEndpoints*: Option[seq[string]]
+    ## Ethereum RPC endpoints (required for RLN validation); multiple for fail-over.
+  rlnContractAddress*: Option[string]
+    ## RLN contract address; when set, RLN validation is enabled.
+  rlnChainId*: Option[uint]
+    ## Chain id the RLN contract is deployed on.
+  rlnEpochSizeSec*: Option[uint]
+    ## RLN epoch size, in seconds.
+  reliabilityEnabled*: Option[bool]
+    ## Enable store-based send reliability.
+
+proc toKernelConf*(m: MessagingConf, mode: WakuMode): ConfResult[KernelConf] =
+  ## Build a `KernelConf` from the operation mode and the messaging configuration.
+  ## The mode sets the kernel protocol flags; each set field is then written to its
+  ## kernel counterpart, and unset fields keep the kernel default.
+  var conf = ?defaultWakuNodeConf()
+
+  case mode
+  of WakuMode.Core:
+    conf.relay = true
+    conf.filter = true
+    conf.lightpush = true
+    conf.discv5Discovery = some(true)
+    conf.peerExchange = true
+    conf.rendezvous = true
+    if conf.rateLimits.len == 0:
+      conf.rateLimits = @["filter:100/1s", "lightpush:5/1s", "px:5/1s"]
+  of WakuMode.Edge:
+    conf.peerExchange = true
+    conf.relay = false
+    conf.filter = false
+    conf.lightpush = false
+    conf.store = false
+
+  if m.clusterId.isSome():
+    conf.clusterId = m.clusterId
+  if m.numShardsInCluster.isSome():
+    conf.numShardsInNetwork = m.numShardsInCluster.get()
+  if m.p2pTcpPort.isSome():
+    conf.tcpPort = m.p2pTcpPort.get()
+  if m.discv5UdpPort.isSome():
+    conf.discv5UdpPort = m.discv5UdpPort.get()
+  if m.listenIpv4.isSome():
+    conf.listenAddress = m.listenIpv4.get()
+  if m.maxMessageSize.isSome():
+    conf.maxMessageSize = m.maxMessageSize.get()
+  if m.entryNodes.isSome():
+    conf.entryNodes = m.entryNodes.get()
+  if m.ethRpcEndpoints.isSome():
+    conf.ethClientUrls = m.ethRpcEndpoints.get().mapIt(EthRpcUrl(it))
+  if m.rlnContractAddress.isSome():
+    conf.rlnRelayEthContractAddress = m.rlnContractAddress.get()
+    conf.rlnRelay = some(true)
+  if m.rlnChainId.isSome():
+    conf.rlnRelayChainId = m.rlnChainId.get()
+  if m.rlnEpochSizeSec.isSome():
+    conf.rlnEpochSizeSec = some(m.rlnEpochSizeSec.get().uint64)
+  if m.reliabilityEnabled.isSome():
+    conf.reliabilityEnabled = m.reliabilityEnabled
+  ok(conf)
diff --git a/logos_delivery/api/messaging_conf_preset.nim b/logos_delivery/api/messaging_conf_preset.nim
new file mode 100644
index 000000000..96833147a
--- /dev/null
+++ b/logos_delivery/api/messaging_conf_preset.nim
@@ -0,0 +1,58 @@
+## Preset resolution and override merge for the Messaging layer.
+##
+## `resolvePreset` turns a network preset name into the Messaging-layer fields it
+## implies; `merge` applies a caller's overrides on top. `startAsClient` uses both
+## before inferring the kernel config. The kernel still resolves the preset itself
+## for the node-local fields a preset does not carry.
+
+import std/options
+import results
+import stint # UInt256.truncate
+
+import logos_delivery/api/messaging_conf
+  # MessagingConf, ConfResult, toNetworkPresetConf
+import logos_delivery/waku/factory/networks_config # NetworkPresetConf, AutoSharding
+
+proc merge*(base, overrides: MessagingConf): MessagingConf =
+  ## Combine two messaging configs field by field: a set `overrides` field wins;
+  ## otherwise the `base` value is kept.
+  result = base
+  if overrides.clusterId.isSome(): result.clusterId = overrides.clusterId
+  if overrides.numShardsInCluster.isSome():
+    result.numShardsInCluster = overrides.numShardsInCluster
+  if overrides.p2pTcpPort.isSome(): result.p2pTcpPort = overrides.p2pTcpPort
+  if overrides.discv5UdpPort.isSome(): result.discv5UdpPort = overrides.discv5UdpPort
+  if overrides.listenIpv4.isSome(): result.listenIpv4 = overrides.listenIpv4
+  if overrides.maxMessageSize.isSome(): result.maxMessageSize = overrides.maxMessageSize
+  if overrides.entryNodes.isSome(): result.entryNodes = overrides.entryNodes
+  if overrides.ethRpcEndpoints.isSome():
+    result.ethRpcEndpoints = overrides.ethRpcEndpoints
+  if overrides.rlnContractAddress.isSome():
+    result.rlnContractAddress = overrides.rlnContractAddress
+  if overrides.rlnChainId.isSome(): result.rlnChainId = overrides.rlnChainId
+  if overrides.rlnEpochSizeSec.isSome():
+    result.rlnEpochSizeSec = overrides.rlnEpochSizeSec
+  if overrides.reliabilityEnabled.isSome():
+    result.reliabilityEnabled = overrides.reliabilityEnabled
+
+proc resolvePreset*(preset: string): ConfResult[MessagingConf] =
+  ## Resolve a network preset name into the Messaging-layer fields it implies.
+  ## Node-local fields (ports, bind address, RPC endpoints) are not preset-defined
+  ## and stay unset. An empty preset resolves to an empty config.
+  let npcOpt = ?toNetworkPresetConf(preset, none(uint16))
+  if npcOpt.isNone():
+    return ok(MessagingConf())
+  let npc = npcOpt.get()
+  var m = MessagingConf()
+  m.clusterId = some(npc.clusterId)
+  if npc.shardingConf.kind == AutoSharding:
+    m.numShardsInCluster = some(npc.shardingConf.numShardsInCluster)
+  m.maxMessageSize = some(npc.maxMessageSize)
+  if npc.entryNodes.len > 0:
+    m.entryNodes = some(npc.entryNodes)
+  if npc.rlnRelay and npc.rlnRelayEthContractAddress.len > 0:
+    m.rlnContractAddress = some(npc.rlnRelayEthContractAddress)
+    m.rlnChainId = some(npc.rlnRelayChainId.truncate(uint))
+    m.rlnEpochSizeSec = some(npc.rlnEpochSizeSec.uint)
+  m.reliabilityEnabled = some(npc.p2pReliability)
+  ok(m)
diff --git a/logos_delivery/channels/channels_conf.nim b/logos_delivery/channels/channels_conf.nim
new file mode 100644
index 000000000..5d817ec5f
--- /dev/null
+++ b/logos_delivery/channels/channels_conf.nim
@@ -0,0 +1,33 @@
+## Reliable-channels configuration.
+
+import std/options
+
+import logos_delivery/channels/segmentation/segmentation_persistence
+  # SegmentationPersistence
+import types/persistence # Persistence (nim-sds)
+
+type ChannelsConf* = object
+  ## Reliable-channels configuration as an all-`Option` partial. Unset fields fall
+  ## back to the defaults used by `createReliableChannel`.
+  # Segmentation
+  segmentationEnableReedSolomon*: Option[bool]
+    ## Add Reed-Solomon parity segments for recovery of lost segments.
+  segmentationSegmentSizeBytes*: Option[int]
+    ## Maximum segment size in bytes.
+  # SDS
+  sdsAcknowledgementTimeoutMs*: Option[int]
+    ## Time to wait before retransmitting an unacknowledged message.
+  sdsMaxRetransmissions*: Option[int]
+    ## Maximum retransmission attempts before delivery fails.
+  sdsCausalHistorySize*: Option[int]
+    ## Number of message ids kept in causal history.
+  # Rate limiting
+  rateLimitEnabled*: Option[bool]
+    ## Enable rate limiting.
+  rateLimitEpochPeriodSec*: Option[int]
+    ## Rate-limit epoch length in seconds.
+  # Pluggable backends (dependency injection)
+  segmentationPersistence*: Option[SegmentationPersistence]
+    ## Persists partial reassembly state across restarts.
+  sdsPersistence*: Option[Persistence]
+    ## Persists SDS local history.
diff --git a/logos_delivery/channels/reliable_channel_manager.nim b/logos_delivery/channels/reliable_channel_manager.nim
index ceb8902e1..ad8f3e12d 100644
--- a/logos_delivery/channels/reliable_channel_manager.nim
+++ b/logos_delivery/channels/reliable_channel_manager.nim
@@ -21,8 +21,10 @@ import logos_delivery/waku/persistency/sds_persistency
 
 import ./reliable_channel
 import ./encryption/noop_encryption
+import ./channels_conf
 
 export reliable_channel
+export channels_conf
 
 const SdsJobId = "sds"
   ## One persistency job shared by every channel's SDS state; rows are
@@ -35,6 +37,9 @@ type ReliableChannelManager* = ref object of ReliableChannelManagerInterface
     ## Default egress dispatch for channels created through this manager.
     ## Constructed at mount time as a closure over `MessagingClient.send`
     ## so the channel layer itself stays callable-only.
+  channelsConf: ChannelsConf
+    ## Configuration applied to channels created by this manager; unset fields
+    ## fall back to the component defaults.
 
 proc start*(self: ReliableChannelManager): Result[void, string] =
   ## Placeholder: per-channel listeners are installed in `ReliableChannel.new`,
@@ -63,11 +68,14 @@ proc sdsPersistence(): Option[Persistence] =
 
 BrokerImplement ReliableChannelManager of ReliableChannelManagerInterface:
   proc new(
-      T: typedesc[ReliableChannelManager], messagingClient: MessagingClientInterface
+      T: typedesc[ReliableChannelManager],
+      messagingClient: MessagingClientInterface,
+      channelsConf: ChannelsConf,
   ): T =
     T(
       channels: initTable[ChannelId, ReliableChannel](),
       messagingClient: messagingClient,
+      channelsConf: channelsConf,
     )
 
   method createReliableChannel*(
@@ -87,19 +95,26 @@ BrokerImplement ReliableChannelManager of ReliableChannelManagerInterface:
     if self.channels.hasKey(channelId):
       return err("channel already exists: " & channelId)
 
+    # Apply the channel configuration, falling back to component defaults for
+    # unset fields.
+    let cc = self.channelsConf
     let segConfig = SegmentationConfig(
-      segmentSizeBytes: DefaultSegmentSizeBytes,
-      enableReedSolomon: false,
-      persistence: nil,
+      segmentSizeBytes: cc.segmentationSegmentSizeBytes.get(DefaultSegmentSizeBytes),
+      enableReedSolomon: cc.segmentationEnableReedSolomon.get(false),
+      persistence: cc.segmentationPersistence.get(nil),
     )
     let sdsConfig = SdsConfig(
-      acknowledgementTimeoutMs: DefaultAcknowledgementTimeoutMs,
-      maxRetransmissions: DefaultMaxRetransmissions,
-      causalHistorySize: DefaultCausalHistorySize,
-      persistence: sdsPersistence(),
+      acknowledgementTimeoutMs:
+        cc.sdsAcknowledgementTimeoutMs.get(DefaultAcknowledgementTimeoutMs),
+      maxRetransmissions: cc.sdsMaxRetransmissions.get(DefaultMaxRetransmissions),
+      causalHistorySize: cc.sdsCausalHistorySize.get(DefaultCausalHistorySize),
+      persistence:
+        if cc.sdsPersistence.isSome(): cc.sdsPersistence else: sdsPersistence(),
     )
     let rateConfig = RateLimitConfig(
-      epochPeriodSec: DefaultEpochPeriodSec, messagesPerEpoch: DefaultMessagesPerEpoch
+      enabled: cc.rateLimitEnabled.get(false),
+      epochPeriodSec: cc.rateLimitEpochPeriodSec.get(DefaultEpochPeriodSec),
+      messagesPerEpoch: DefaultMessagesPerEpoch,
     )
 
     let chn = ReliableChannel.new(
diff --git a/logos_delivery/logos_delivery.nim b/logos_delivery/logos_delivery.nim
index 5ddb2dec5..c8f938a63 100644
--- a/logos_delivery/logos_delivery.nim
+++ b/logos_delivery/logos_delivery.nim
@@ -10,13 +10,14 @@
 ## does NOT start it. `kernel()` is a stub until a KernelImpl exists.
 
 import results, chronos
-import std/options # some()/Option for WakuNodeConf.mode
 import std/json # newJArray/newJObject/%*/pretty in getAvailableConfigs
 
 import brokers/broker_context, brokers/broker_interface, brokers/broker_implement
 import logos_delivery/api/logos_delivery_interface as logosdelivery_iface
 import logos_delivery/api/types as api_types
 import logos_delivery/api/kernel_interface as kernel_iface
+import logos_delivery/api/messaging_conf # MessagingConf
+import logos_delivery/api/messaging_conf_preset # resolvePreset, merge
 
 import
   logos_delivery/waku/factory/waku,
@@ -30,6 +31,7 @@ type LogosDelivery* = ref object of LogosDeliveryInterface
   waku: Waku ## the owned node facade (built in initializeRequest)
   messagingClient: MessagingClient
   reliableChannelManager: ReliableChannelManager
+  channelsConf: ChannelsConf ## set by startAsClient; applied when channels mount
 
 proc loadConf(configPath: string): Result[WakuNodeConf, string] =
   ## Delegates to cli_args' concrete loader so confutils' `load` macro expands in
@@ -59,7 +61,7 @@ proc initReliableChannelManager(
 ): Result[ReliableChannelManager, string] =
   return ok(
     ReliableChannelManager.createUnderContext(
-      globalBrokerContext(), self.messagingClient
+      globalBrokerContext(), self.messagingClient, self.channelsConf
     )
   )
 
@@ -100,6 +102,8 @@ BrokerImplement LogosDelivery of LogosDeliveryInterface:
   method startAsNode(
       self: LogosDelivery, config: string
   ): Future[Result[void, string]] {.async.} =
+    ## Load a complete node configuration from `config` and start a bare kernel
+    ## node without a messaging client.
     if not self.waku.isNil():
       return err("already initialized")
     let conf = loadConf(config).valueOr:
@@ -117,7 +121,11 @@ BrokerImplement LogosDelivery of LogosDeliveryInterface:
       return err("initialize failed: " & e.msg)
 
   method startAsClient(
-      self: LogosDelivery, mode: api_types.WakuMode, preset: string
+      self: LogosDelivery,
+      mode: api_types.WakuMode,
+      preset: string,
+      overrides: MessagingConf,
+      channelsConf: ChannelsConf,
   ): Future[Result[MessagingClientInterface, string]] {.async.} =
     if not self.messagingClient.isNil():
       return err("already initialized")
@@ -126,9 +134,14 @@ BrokerImplement LogosDelivery of LogosDeliveryInterface:
         "already started as node; cannot start as client, but you can use as client"
       )
 
+    self.channelsConf = channelsConf
     try:
-      var conf: WakuNodeConf = ?defaultWakuNodeConf()
-      conf.mode = some(mode)
+      # Resolve the preset into the messaging fields it implies, apply the caller's
+      # overrides on top, then infer the kernel configuration. The kernel still
+      # resolves the preset itself for the node-local fields a preset does not carry.
+      let base = ?resolvePreset(preset)
+      let msgConf = base.merge(overrides)
+      var conf: KernelConf = ?msgConf.toKernelConf(mode)
       conf.preset = preset
 
       self.waku = (await createNode(conf)).valueOr:
diff --git a/logos_delivery/waku/api/api.nim b/logos_delivery/waku/api/api.nim
index 025a65179..a991e6106 100644
--- a/logos_delivery/waku/api/api.nim
+++ b/logos_delivery/waku/api/api.nim
@@ -62,7 +62,7 @@ proc mountReliableChannelManager*(w: Waku): Result[void, string] =
     return ok()
 
   w.reliableChannelManager = ReliableChannelManager.createUnderContext(
-    w.brokerCtx, MessagingClientInterface(w.messagingClient)
+    w.brokerCtx, MessagingClientInterface(w.messagingClient), ChannelsConf()
   )
   return ok()
 
diff --git a/tests/api/test_all.nim b/tests/api/test_all.nim
index 56be19c27..ab4b18f77 100644
--- a/tests/api/test_all.nim
+++ b/tests/api/test_all.nim
@@ -3,6 +3,7 @@
 import
   ./test_entry_nodes,
   ./test_node_conf,
+  ./test_messaging_conf,
   ./test_api_send,
   ./test_api_subscription,
   ./test_api_receive,
diff --git a/tests/api/test_api_health.nim b/tests/api/test_api_health.nim
index e448164af..01e81625b 100644
--- a/tests/api/test_api_health.nim
+++ b/tests/api/test_api_health.nim
@@ -16,6 +16,7 @@ import
   logos_delivery/waku/common/waku_protocol,
   logos_delivery/waku/factory/waku_conf
 import tools/confutils/cli_args
+import logos_delivery/api/messaging_conf
 
 const TestTimeout = chronos.seconds(10)
 const DefaultShard = PubsubTopic("/waku/2/rs/3/0")
@@ -92,9 +93,8 @@ suite "LM API health checking":
     serviceNode.wakuRelay.subscribe(DefaultShard, dummyHandler)
 
     lockNewGlobalBrokerContext:
-      var conf = defaultWakuNodeConf().valueOr:
+      var conf = MessagingConf().toKernelConf(WakuMode.Core).valueOr:
         raiseAssert error
-      conf.mode = some(WakuMode.Core)
       conf.listenAddress = parseIpAddress("0.0.0.0")
       conf.tcpPort = Port(0)
       conf.discv5UdpPort = Port(0)
@@ -271,9 +271,8 @@ suite "LM API health checking":
     var edgeWaku: Waku
 
     lockNewGlobalBrokerContext:
-      var edgeConf = defaultWakuNodeConf().valueOr:
+      var edgeConf = MessagingConf().toKernelConf(WakuMode.Edge).valueOr:
         raiseAssert error
-      edgeConf.mode = some(WakuMode.Edge)
       edgeConf.listenAddress = parseIpAddress("0.0.0.0")
       edgeConf.tcpPort = Port(0)
       edgeConf.discv5UdpPort = Port(0)
diff --git a/tests/api/test_api_receive.nim b/tests/api/test_api_receive.nim
index 35061ec81..dc97c6b54 100644
--- a/tests/api/test_api_receive.nim
+++ b/tests/api/test_api_receive.nim
@@ -22,6 +22,7 @@ import
   ]
 import logos_delivery/waku/factory/waku_conf
 import tools/confutils/cli_args
+import logos_delivery/api/messaging_conf
 
 const TestTimeout = chronos.seconds(60)
 
@@ -83,9 +84,8 @@ proc waitForConnectionStatus(
     await health_events.ConnectionStatusChangeEvent.dropListener(brokerCtx, handle)
 
 proc createApiNodeConf(numShards: uint16 = 1): WakuNodeConf =
-  var conf = defaultWakuNodeConf().valueOr:
+  var conf = MessagingConf().toKernelConf(cli_args.WakuMode.Core).valueOr:
     raiseAssert error
-  conf.mode = some(cli_args.WakuMode.Core)
   conf.listenAddress = parseIpAddress("0.0.0.0")
   conf.tcpPort = Port(0)
   conf.discv5UdpPort = Port(0)
diff --git a/tests/api/test_api_send.nim b/tests/api/test_api_send.nim
index c406e16a9..6fe028343 100644
--- a/tests/api/test_api_send.nim
+++ b/tests/api/test_api_send.nim
@@ -8,6 +8,7 @@ import ../waku_archive/archive_utils
 import logos_delivery, logos_delivery/waku/[waku_node, waku_core, waku_relay/protocol]
 import logos_delivery/waku/factory/waku_conf
 import tools/confutils/cli_args
+import logos_delivery/api/messaging_conf
 
 type SendEventOutcome {.pure.} = enum
   Sent
@@ -120,9 +121,8 @@ proc validate(
     check requestId == expectedRequestId
 
 proc createApiNodeConf(mode: cli_args.WakuMode = cli_args.WakuMode.Core): WakuNodeConf =
-  var conf = defaultWakuNodeConf().valueOr:
+  var conf = MessagingConf().toKernelConf(mode).valueOr:
     raiseAssert error
-  conf.mode = some(mode)
   conf.listenAddress = parseIpAddress("0.0.0.0")
   conf.tcpPort = Port(0)
   conf.discv5UdpPort = Port(0)
diff --git a/tests/api/test_api_subscription.nim b/tests/api/test_api_subscription.nim
index 2a8108b39..d34484f9d 100644
--- a/tests/api/test_api_subscription.nim
+++ b/tests/api/test_api_subscription.nim
@@ -19,6 +19,7 @@ import
   ]
 import logos_delivery/waku/factory/waku_conf
 import tools/confutils/cli_args
+import logos_delivery/api/messaging_conf
 
 const TestTimeout = chronos.seconds(10)
 const NegativeTestTimeout = chronos.seconds(2)
@@ -71,9 +72,8 @@ type TestNetwork = ref object
 proc createApiNodeConf(
     mode: cli_args.WakuMode = cli_args.WakuMode.Core, numShards: uint16 = 1
 ): WakuNodeConf =
-  var conf = defaultWakuNodeConf().valueOr:
+  var conf = MessagingConf().toKernelConf(mode).valueOr:
     raiseAssert error
-  conf.mode = some(mode)
   conf.listenAddress = parseIpAddress("0.0.0.0")
   conf.tcpPort = Port(0)
   conf.discv5UdpPort = Port(0)
diff --git a/tests/api/test_messaging_conf.nim b/tests/api/test_messaging_conf.nim
new file mode 100644
index 000000000..f6efb89b8
--- /dev/null
+++ b/tests/api/test_messaging_conf.nim
@@ -0,0 +1,108 @@
+{.used.}
+
+import std/options, results, testutils/unittests
+import std/nativesockets # Port
+
+import logos_delivery/api/types # WakuMode
+import logos_delivery/api/messaging_conf
+  # MessagingConf, toKernelConf, defaultWakuNodeConf
+import logos_delivery/api/messaging_conf_preset # resolvePreset, merge
+
+suite "MessagingConf - toKernelConf inference":
+  test "Core mode enables relay and service protocols":
+    let conf = MessagingConf().toKernelConf(WakuMode.Core).valueOr:
+      raiseAssert error
+    check:
+      conf.relay == true
+      conf.filter == true
+      conf.lightpush == true
+      conf.discv5Discovery == some(true)
+      conf.peerExchange == true
+      conf.rendezvous == true
+
+  test "Edge mode disables relay and service protocols":
+    let conf = MessagingConf().toKernelConf(WakuMode.Edge).valueOr:
+      raiseAssert error
+    check:
+      conf.relay == false
+      conf.filter == false
+      conf.lightpush == false
+      conf.store == false
+      conf.peerExchange == true
+
+  test "clusterId is applied only when set":
+    let setConf = MessagingConf(clusterId: some(7'u16)).toKernelConf(WakuMode.Core).valueOr:
+      raiseAssert error
+    check setConf.clusterId == some(7'u16)
+
+    let kernelDefault = defaultWakuNodeConf().valueOr:
+      raiseAssert error
+    let unsetConf = MessagingConf().toKernelConf(WakuMode.Core).valueOr:
+      raiseAssert error
+    check unsetConf.clusterId == kernelDefault.clusterId
+
+  test "p2pTcpPort sets the kernel tcpPort":
+    let conf = MessagingConf(p2pTcpPort: some(Port(60123))).toKernelConf(WakuMode.Core).valueOr:
+      raiseAssert error
+    check conf.tcpPort.uint16 == 60123'u16
+
+  test "reliabilityEnabled is applied to the kernel":
+    let conf = MessagingConf(reliabilityEnabled: some(true)).toKernelConf(WakuMode.Core).valueOr:
+      raiseAssert error
+    check conf.reliabilityEnabled == some(true)
+
+  test "rlnContractAddress sets the contract and enables rlnRelay":
+    let conf = MessagingConf(rlnContractAddress: some("0xabc")).toKernelConf(WakuMode.Core).valueOr:
+      raiseAssert error
+    check:
+      conf.rlnRelayEthContractAddress == "0xabc"
+      conf.rlnRelay == some(true)
+
+  test "ethRpcEndpoints maps to the kernel ethClientUrls":
+    let mc = MessagingConf(ethRpcEndpoints: some(@["http://node:8545"]))
+    let conf = mc.toKernelConf(WakuMode.Core).valueOr:
+      raiseAssert error
+    check:
+      conf.ethClientUrls.len == 1
+      string(conf.ethClientUrls[0]) == "http://node:8545"
+
+  test "rlnChainId and rlnEpochSizeSec map to the kernel":
+    let mc = MessagingConf(rlnChainId: some(5'u), rlnEpochSizeSec: some(600'u))
+    let conf = mc.toKernelConf(WakuMode.Core).valueOr:
+      raiseAssert error
+    check:
+      conf.rlnRelayChainId == 5'u
+      conf.rlnEpochSizeSec == some(600'u64)
+
+suite "MessagingConf - preset resolution and merge":
+  test "resolvePreset twn populates the network fields":
+    let m = resolvePreset("twn").valueOr:
+      raiseAssert error
+    check:
+      m.clusterId == some(1'u16)
+      m.numShardsInCluster == some(8'u16)
+      m.reliabilityEnabled == some(false)
+      m.rlnContractAddress.isSome()
+
+  test "resolvePreset logosdev sets cluster 2 and reliability":
+    let m = resolvePreset("logosdev").valueOr:
+      raiseAssert error
+    check:
+      m.clusterId == some(2'u16)
+      m.reliabilityEnabled == some(true)
+      m.rlnContractAddress.isNone()
+
+  test "resolvePreset empty is a no-op":
+    let m = resolvePreset("").valueOr:
+      raiseAssert error
+    check:
+      m.clusterId.isNone()
+      m.reliabilityEnabled.isNone()
+
+  test "merge: overrides win over the preset base, base kept otherwise":
+    let base = resolvePreset("twn").valueOr:
+      raiseAssert error
+    let merged = base.merge(MessagingConf(clusterId: some(99'u16)))
+    check:
+      merged.clusterId == some(99'u16)
+      merged.numShardsInCluster == some(8'u16)
diff --git a/tests/api/test_node_conf.nim b/tests/api/test_node_conf.nim
index b89efb0e4..98244828a 100644
--- a/tests/api/test_node_conf.nim
+++ b/tests/api/test_node_conf.nim
@@ -4,6 +4,7 @@ import std/[options, strutils], results, stint, testutils/unittests
 import json_serialization, confutils, confutils/std/net
 import
   tools/confutils/cli_args,
+  logos_delivery/api/messaging_conf,
   tools/confutils/conf_from_json,
   logos_delivery/waku/api/api_conf,
   logos_delivery/waku/factory/waku_conf,
@@ -11,18 +12,13 @@ import
   logos_delivery/waku/factory/conf_builder/conf_builder,
   logos_delivery/waku/common/logging
 
-suite "WakuNodeConf - mode-driven toWakuConf":
+suite "MessagingConf mode - toKernelConf - toWakuConf":
   test "Core mode enables service protocols":
-    ## Given
-    var conf = defaultWakuNodeConf().valueOr:
+    let conf = MessagingConf(clusterId: some(1'u16)).toKernelConf(WakuMode.Core).valueOr:
       raiseAssert error
-    conf.mode = some(WakuMode.Core)
-    conf.clusterId = some(1'u16)
 
-    ## When
     let wakuConfRes = conf.toWakuConf()
 
-    ## Then
     require wakuConfRes.isOk()
     let wakuConf = wakuConfRes.get()
     require wakuConf.validate().isOk()
@@ -34,16 +30,11 @@ suite "WakuNodeConf - mode-driven toWakuConf":
       wakuConf.clusterId == 1
 
   test "Edge mode disables service protocols":
-    ## Given
-    var conf = defaultWakuNodeConf().valueOr:
+    let conf = MessagingConf(clusterId: some(1'u16)).toKernelConf(WakuMode.Edge).valueOr:
       raiseAssert error
-    conf.mode = some(WakuMode.Edge)
-    conf.clusterId = some(1'u16)
 
-    ## When
     let wakuConfRes = conf.toWakuConf()
 
-    ## Then
     require wakuConfRes.isOk()
     let wakuConf = wakuConfRes.get()
     require wakuConf.validate().isOk()
@@ -54,44 +45,6 @@ suite "WakuNodeConf - mode-driven toWakuConf":
       wakuConf.storeServiceConf.isSome() == false
       wakuConf.peerExchangeService == true
 
-  test "WakuMode.none uses explicit CLI flags as-is":
-    ## Given
-    var conf = defaultWakuNodeConf().valueOr:
-      raiseAssert error
-    conf.mode = none[WakuMode]()
-    conf.relay = true
-    conf.lightpush = false
-    conf.clusterId = some(5'u16)
-
-    ## When
-    let wakuConfRes = conf.toWakuConf()
-
-    ## Then
-    require wakuConfRes.isOk()
-    let wakuConf = wakuConfRes.get()
-    require wakuConf.validate().isOk()
-    check:
-      wakuConf.relay == true
-      wakuConf.lightPush == false
-      wakuConf.clusterId == 5
-
-  test "Core mode overrides individual protocol flags":
-    ## Given - user sets relay=false but mode=Core should override
-    var conf = defaultWakuNodeConf().valueOr:
-      raiseAssert error
-    conf.mode = some(WakuMode.Core)
-    conf.relay = false # will be overridden by Core mode
-
-    ## When
-    let wakuConfRes = conf.toWakuConf()
-
-    ## Then
-    require wakuConfRes.isOk()
-    let wakuConf = wakuConfRes.get()
-    require wakuConf.validate().isOk()
-    check:
-      wakuConf.relay == true # mode overrides
-
 suite "WakuNodeConf - JSON parsing with fieldPairs":
   test "Empty JSON produces valid default conf":
     ## Given / When
@@ -101,31 +54,9 @@ suite "WakuNodeConf - JSON parsing with fieldPairs":
     require confRes.isOk()
     let conf = confRes.get()
     check:
-      conf.mode == none[WakuMode]()
       conf.clusterId.isNone()
       conf.logLevel == logging.LogLevel.INFO
 
-  test "JSON with mode and clusterId":
-    ## Given / When
-    let confRes = parseNodeConfFromJson("""{"mode": "Core", "clusterId": 42}""")
-
-    ## Then
-    require confRes.isOk()
-    let conf = confRes.get()
-    check:
-      conf.mode == some(WakuMode.Core)
-      conf.clusterId == some(42'u16)
-
-  test "JSON with Edge mode":
-    ## Given / When
-    let confRes = parseNodeConfFromJson("""{"mode": "Edge"}""")
-
-    ## Then
-    require confRes.isOk()
-    let conf = confRes.get()
-    check:
-      conf.mode == some(WakuMode.Edge)
-
   test "JSON with logLevel":
     ## Given / When
     let confRes = parseNodeConfFromJson("""{"logLevel": "DEBUG"}""")
@@ -254,49 +185,9 @@ suite "WakuNodeConf - preset integration":
     check wakuConfRes.isErr()
 
 suite "WakuNodeConf JSON -> WakuConf integration":
-  test "Core mode JSON config produces valid WakuConf":
-    ## Given
-    let confRes = parseNodeConfFromJson(
-      """{"mode": "Core", "clusterId": 55, "numShardsInNetwork": 6}"""
-    )
-    require confRes.isOk()
-    let conf = confRes.get()
-
-    ## When
-    let wakuConfRes = conf.toWakuConf()
-
-    ## Then
-    require wakuConfRes.isOk()
-    let wakuConf = wakuConfRes.get()
-    require wakuConf.validate().isOk()
-    check:
-      wakuConf.relay == true
-      wakuConf.lightPush == true
-      wakuConf.peerExchangeService == true
-      wakuConf.clusterId == 55
-      wakuConf.shardingConf.numShardsInCluster == 6
-
-  test "Edge mode JSON config produces valid WakuConf":
-    ## Given
-    let confRes = parseNodeConfFromJson("""{"mode": "Edge", "clusterId": 1}""")
-    require confRes.isOk()
-    let conf = confRes.get()
-
-    ## When
-    let wakuConfRes = conf.toWakuConf()
-
-    ## Then
-    require wakuConfRes.isOk()
-    let wakuConf = wakuConfRes.get()
-    require wakuConf.validate().isOk()
-    check:
-      wakuConf.relay == false
-      wakuConf.lightPush == false
-      wakuConf.peerExchangeService == true
-
   test "JSON with preset produces valid WakuConf":
     ## Given
-    let confRes = parseNodeConfFromJson("""{"mode": "Core", "preset": "logosdev"}""")
+    let confRes = parseNodeConfFromJson("""{"preset": "logosdev"}""")
     require confRes.isOk()
     let conf = confRes.get()
 
@@ -314,7 +205,7 @@ suite "WakuNodeConf JSON -> WakuConf integration":
   test "JSON with static nodes":
     ## Given
     let confRes = parseNodeConfFromJson(
-      """{"mode": "Core", "clusterId": 42, "staticnodes": ["/ip4/127.0.0.1/tcp/60000/p2p/16Uuu2HBmAcHvhLqQKwSSbX6BG5JLWUDRcaLVrehUVqpw7fz1hbYc"]}"""
+      """{"clusterId": 42, "staticnodes": ["/ip4/127.0.0.1/tcp/60000/p2p/16Uuu2HBmAcHvhLqQKwSSbX6BG5JLWUDRcaLVrehUVqpw7fz1hbYc"]}"""
     )
     require confRes.isOk()
     let conf = confRes.get()
diff --git a/tests/channels/test_reliable_channel_send_receive.nim b/tests/channels/test_reliable_channel_send_receive.nim
index 1f90541b1..89f88fd95 100644
--- a/tests/channels/test_reliable_channel_send_receive.nim
+++ b/tests/channels/test_reliable_channel_send_receive.nim
@@ -12,6 +12,7 @@ import logos_delivery/waku/[waku_node, waku_core]
 import logos_delivery/waku/factory/waku_conf
 import logos_delivery/waku/events/message_events as waku_message_events
 import tools/confutils/cli_args
+import logos_delivery/api/messaging_conf
 
 import logos_delivery/channels/reliable_channel_manager
 import logos_delivery/channels/encryption/noop_encryption
@@ -28,9 +29,8 @@ import logos_delivery/api/messaging_client_interface
 const TestTimeout = chronos.seconds(15)
 
 proc createApiNodeConf(): WakuNodeConf =
-  var conf = defaultWakuNodeConf().valueOr:
+  var conf = MessagingConf().toKernelConf(cli_args.WakuMode.Core).valueOr:
     raiseAssert error
-  conf.mode = some(cli_args.WakuMode.Core)
   conf.listenAddress = parseIpAddress("0.0.0.0")
   conf.tcpPort = Port(0)
   conf.discv5UdpPort = Port(0)
diff --git a/tests/test_waku.nim b/tests/test_waku.nim
index d69b54e4b..9a085027a 100644
--- a/tests/test_waku.nim
+++ b/tests/test_waku.nim
@@ -6,15 +6,15 @@ import chronos, testutils/unittests
 
 import logos_delivery
 import tools/confutils/cli_args
+import logos_delivery/api/messaging_conf
 import logos_delivery/waku/factory/networks_config
 import logos_delivery/waku/factory/conf_builder/conf_builder
 
 suite "Waku API - Create node":
   asyncTest "Create node with minimal configuration":
     ## Given
-    var nodeConf = defaultWakuNodeConf().valueOr:
-      raiseAssert "defaultWakuNodeConf failed: " & error
-    nodeConf.mode = some(WakuMode.Core)
+    var nodeConf = MessagingConf().toKernelConf(WakuMode.Core).valueOr:
+      raiseAssert "toKernelConf failed: " & error
     nodeConf.clusterId = some(3'u16)
     nodeConf.rest = false
 
@@ -32,9 +32,8 @@ suite "Waku API - Create node":
 
   asyncTest "Create node with full configuration":
     ## Given
-    var nodeConf = defaultWakuNodeConf().valueOr:
-      raiseAssert "defaultWakuNodeConf failed: " & error
-    nodeConf.mode = some(WakuMode.Core)
+    var nodeConf = MessagingConf().toKernelConf(WakuMode.Core).valueOr:
+      raiseAssert "toKernelConf failed: " & error
     nodeConf.clusterId = some(99'u16)
     nodeConf.rest = false
     nodeConf.numShardsInNetwork = 16
@@ -64,9 +63,8 @@ suite "Waku API - Create node":
 
   asyncTest "Create node with mixed entry nodes (enrtree, multiaddr)":
     ## Given
-    var nodeConf = defaultWakuNodeConf().valueOr:
-      raiseAssert "defaultWakuNodeConf failed: " & error
-    nodeConf.mode = some(WakuMode.Core)
+    var nodeConf = MessagingConf().toKernelConf(WakuMode.Core).valueOr:
+      raiseAssert "toKernelConf failed: " & error
     nodeConf.clusterId = some(42'u16)
     nodeConf.rest = false
     nodeConf.entryNodes = @[
diff --git a/tools/confutils/cli_args.nim b/tools/confutils/cli_args.nim
index 5a79a4945..5309e356f 100644
--- a/tools/confutils/cli_args.nim
+++ b/tools/confutils/cli_args.nim
@@ -163,13 +163,6 @@ type WakuNodeConf* = object
     .}: seq[ProtectedShard]
 
     ## General node config
-    mode* {.
-      desc:
-        "Node operation mode. 'Core' enables relay+service protocols. 'Edge' enables client-only protocols. Default (unset): explicit CLI flags used.",
-      defaultValue: none(WakuMode),
-      name: "mode"
-    .}: Option[WakuMode]
-
     preset* {.
       desc:
         "Network preset to use. 'twn' is The RLN-protected Waku Network (cluster 1). 'logos.dev' is the Logos Dev Network (cluster 2). 'logos.test' is the Logos Test Network (cluster 2). Overrides other values.",
@@ -993,7 +986,7 @@ proc toKeystoreGeneratorConf*(n: WakuNodeConf): RlnKeystoreGeneratorConf =
     credPassword: n.rlnRelayCredPassword,
   )
 
-proc toNetworkPresetConf(
+proc toNetworkPresetConf*(
     preset: string, clusterId: Option[uint16]
 ): ConfResult[Option[NetworkPresetConf]] =
   var lcPreset = toLowerAscii(preset)
@@ -1220,25 +1213,4 @@ proc toWakuConf*(n: WakuNodeConf): ConfResult[WakuConf] =
       chronos.seconds(n.kadServiceLookupIntervalSec.int64)
     )
 
-  # Mode-driven configuration overrides. `none` (formerly `noMode`) means:
-  # use explicit CLI flags as-is.
-  if n.mode.isSome():
-    case n.mode.get()
-    of WakuMode.Core:
-      b.withRelay(true)
-      b.filterServiceConf.withEnabled(true)
-      b.withLightPush(true)
-      b.discv5Conf.withEnabled(true)
-      b.withPeerExchange(true)
-      b.withRendezvous(true)
-      b.rateLimitConf.withRateLimitsIfNotAssigned(
-        @["filter:100/1s", "lightpush:5/1s", "px:5/1s"]
-      )
-    of WakuMode.Edge:
-      b.withPeerExchange(true)
-      b.withRelay(false)
-      b.filterServiceConf.withEnabled(false)
-      b.withLightPush(false)
-      b.storeServiceConf.withEnabled(false)
-
   return b.build()