diff --git a/nim_chat_poc.nimble b/nim_chat_poc.nimble
index 7c10bce..fa4866a 100644
--- a/nim_chat_poc.nimble
+++ b/nim_chat_poc.nimble
@@ -5,13 +5,18 @@ author        = "jazzz"
 description   = "An example of the chat sdk in Nim"
 license       = "MIT"
 srcDir        = "src"
-bin           = @["nim_chat_poc"]
+bin           = @["nim_chat_poc", "dev"]
 
 
 # Basic build task
 task initialize, "Initialize the project after cloning":
   exec "./initialize.sh"
 
+# # Clean 
+# task cleandeps, "Remove and refresh dependencies":
+#   rm -rf ~/.nimble/pkgs2/sds-*
+#   rm -rf ~/.nimble/pkgcache/githubcom_jazzznimsds*
+
 
 # Dependencies
 
@@ -27,3 +32,4 @@ requires "confutils"
 requires "eth"
 requires "regex"
 requires "web3"
+requires "file:///Users/jazzz/dev/nim-sds#dev"
diff --git a/protos/private_v1.proto b/protos/private_v1.proto
index f5eb691..9d12c4f 100644
--- a/protos/private_v1.proto
+++ b/protos/private_v1.proto
@@ -14,7 +14,7 @@ message Placeholder {
 message PrivateV1Frame {                 
     string conversation_id = 1;
     bytes sender = 2;                
-
+    int64 timestamp = 3;          // Sender reported timestamp
 	oneof frame_type {
 		common_frames.ContentFrame content = 10;
         Placeholder placeholder = 11;
diff --git a/src/chat_sdk/client.nim b/src/chat_sdk/client.nim
index 33998d5..66ad952 100644
--- a/src/chat_sdk/client.nim
+++ b/src/chat_sdk/client.nim
@@ -6,6 +6,7 @@
 import # Foreign
   chronicles,
   chronos,
+  sds,
   sequtils,
   std/tables,
   std/sequtils,
@@ -34,8 +35,10 @@ logScope:
 #################################################
 
 type
-  MessageCallback[T] = proc(conversation: Conversation, msg: T): Future[void] {.async.}
-  NewConvoCallback = proc(conversation: Conversation): Future[void] {.async.}
+  MessageCallback*[T] = proc(conversation: Conversation, msg: T): Future[void] {.async.}
+  NewConvoCallback* = proc(conversation: Conversation): Future[void] {.async.}
+  ReadReceiptCallback* = proc(conversation: Conversation,
+      msgId: string): Future[void] {.async.}
 
 
 type KeyEntry* = object
@@ -53,6 +56,7 @@ type Client* = ref object
 
   newMessageCallbacks: seq[MessageCallback[ContentFrame]]
   newConvoCallbacks: seq[NewConvoCallback]
+  readReceiptCallbacks: seq[ReadReceiptCallback]
 
 #################################################
 # Constructors
@@ -64,6 +68,8 @@ proc newClient*(name: string, cfg: WakuConfig): Client {.raises: [IOError,
   try:
     let waku = initWakuClient(cfg)
 
+    let rm = newReliabilityManager().valueOr:
+      raise newException(ValueError, fmt"SDS InitializationError")
 
     var q = QueueRef(queue: newAsyncQueue[ChatPayload](10))
     var c = Client(ident: createIdentity(name),
@@ -130,6 +136,14 @@ proc notifyNewConversation(client: Client, convo: Conversation) =
   for cb in client.newConvoCallbacks:
     discard cb(convo)
 
+proc onReadReceipt*(client: Client, callback: ReadReceiptCallback) =
+  client.readReceiptCallbacks.add(callback)
+
+proc notifyReadReceipt(client: Client, convo: Conversation,
+    messageId: MessageId) =
+  for cb in client.readReceiptCallbacks:
+    discard cb(convo, messageId)
+
 #################################################
 # Functional
 #################################################
@@ -144,7 +158,7 @@ proc createIntroBundle*(self: var Client): IntroBundle =
   self.keyStore[ephemeralKey.getPublicKey().bytes().bytesToHex()] = KeyEntry(
     keyType: "ephemeral",
     privateKey: ephemeralKey,
-    timestamp: getTimestamp()
+    timestamp: getCurrentTimestamp()
   )
 
   result = IntroBundle(
@@ -189,11 +203,19 @@ proc newPrivateConversation*(client: Client,
     participant: @(destPubkey.bytes()),
     participantEphemeralId: introBundle.ephemeralId,
     discriminator: "test"
-  )
+    )
+
+
+
   let env = wrapEnv(encrypt(InboxV1Frame(invitePrivateV1: invite,
       recipient: "")), convoId)
 
-  let convo = initPrivateV1(client.identity(), destPubkey, "default")
+  let deliveryAckCb = proc(
+        conversation: Conversation,
+      msgId: string): Future[void] {.async.} =
+    client.notifyReadReceipt(conversation, msgId)
+
+  let convo = initPrivateV1(client.identity(), destPubkey, "default", deliveryAckCb)
   client.addConversation(convo)
 
   # TODO: Subscribe to new content topic
diff --git a/src/chat_sdk/conversation_store.nim b/src/chat_sdk/conversation_store.nim
index 38383f6..4eb7493 100644
--- a/src/chat_sdk/conversation_store.nim
+++ b/src/chat_sdk/conversation_store.nim
@@ -4,6 +4,7 @@ import ./conversations/convo_type
 import crypto
 import identity
 import proto_types
+import types
 
 type ConvoId = string
 
@@ -16,3 +17,5 @@ type
 
     proc notifyNewMessage(self: Self, convo: Conversation,
         content: ContentFrame)
+    proc notifyReadReceipt(self: Self, convo: Conversation,
+        msgId: MessageId)
diff --git a/src/chat_sdk/conversations/private_v1.nim b/src/chat_sdk/conversations/private_v1.nim
index 6ee2e99..00d2762 100644
--- a/src/chat_sdk/conversations/private_v1.nim
+++ b/src/chat_sdk/conversations/private_v1.nim
@@ -1,10 +1,12 @@
 
-
+import blake2
 import chronicles
 import chronos
+import sds
 import std/[sequtils, strutils, strformat]
 import std/algorithm
 import sugar
+import tables
 
 import ../conversation_store
 import ../crypto
@@ -13,15 +15,16 @@ import ../delivery/waku_client
 import ../[
   identity,
   proto_types,
+  types,
   utils
 ]
 import convo_type
 
 
-
 type
   PrivateV1* = ref object of Conversation
     # Placeholder for PrivateV1 conversation type
+    sdsClient: ReliabilityManager
     owner: Identity
     topic: string
     participants: seq[PublicKey]
@@ -48,27 +51,81 @@ proc derive_topic(participants: seq[PublicKey], discriminator: string): string =
   ## Derives a topic from the participants' public keys.
   return "/convo/private/" & getConvoIdRaw(participants, discriminator)
 
+proc calcMsgId(self: PrivateV1, msgBytes: seq[byte]): string =
+  let s = fmt"{self.getConvoId()}|{msgBytes}"
+  result = getBlake2b(s, 16, "")
+
+
 proc encrypt*(convo: PrivateV1, frame: PrivateV1Frame): EncryptedPayload =
   result = EncryptedPayload(plaintext: Plaintext(payload: encode(frame)))
 
 proc decrypt*(convo: PrivateV1, enc: EncryptedPayload): PrivateV1Frame =
   result = decode(enc.plaintext.payload, PrivateV1Frame).get()
 
+
+proc wireCallbacks(convo: PrivateV1, deliveryAckCb: proc(
+        conversation: Conversation,
+      msgId: string): Future[void] {.async.} = nil) =
+  ## Accepts lambdas/functions to be called from Reliability Manager callbacks.
+  let funcMsg = proc(messageId: SdsMessageID,
+      channelId: SdsChannelID) {.gcsafe.} =
+    debug "sds message ready", messageId = messageId,
+        channelId = channelId
+
+  let funcDeliveryAck = proc(messageId: SdsMessageID,
+      channelId: SdsChannelID) {.gcsafe.} =
+    debug "sds message ack", messageId = messageId,
+        channelId = channelId, cb = repr(deliveryAckCb)
+
+    if deliveryAckCb != nil:
+      asyncSpawn deliveryAckCb(convo, messageId)
+
+  let funcDroppedMsg = proc(messageId: SdsMessageID, missingDeps: seq[
+      SdsMessageID], channelId: SdsChannelID) {.gcsafe.} =
+    debug "sds message missing", messageId = messageId,
+        missingDeps = missingDeps, channelId = channelId
+
+  convo.sdsClient.setCallbacks(
+    funcMsg, funcDeliveryAck, funcDroppedMsg
+  )
+
+
+
 proc initPrivateV1*(owner: Identity, participant: PublicKey,
-    discriminator: string = "default"): PrivateV1 =
+        discriminator: string = "default", deliveryAckCb: proc(
+        conversation: Conversation,
+      msgId: string): Future[void] {.async.} = nil):
+          PrivateV1 =
 
   var participants = @[owner.getPubkey(), participant];
 
-  return PrivateV1(
+  var rm = newReliabilityManager().valueOr:
+    raise newException(ValueError, fmt"sds initialization: {repr(error)}")
+
+  result = PrivateV1(
+    sdsClient: rm,
     owner: owner,
     topic: derive_topic(participants, discriminator),
     participants: participants,
     discriminator: discriminator
   )
 
+  result.wireCallbacks(deliveryAckCb)
+
+  result.sdsClient.ensureChannel(result.getConvoId()).isOkOr:
+    raise newException(ValueError, "bad sds channel")
+
 proc sendFrame(self: PrivateV1, ds: WakuClient,
     msg: PrivateV1Frame): Future[void]{.async.} =
-  let encryptedBytes = EncryptedPayload(plaintext: Plaintext(payload: encode(msg)))
+
+  let frameBytes = encode(msg)
+  let msgId = self.calcMsgId(frameBytes)
+  let sdsPayload = self.sdsClient.wrapOutgoingMessage(frameBytes, msgId,
+      self.getConvoId()).valueOr:
+    raise newException(ValueError, fmt"sds wrapOutgoingMessage failed: {repr(error)}")
+
+  let encryptedBytes = EncryptedPayload(plaintext: Plaintext(
+      payload: sdsPayload))
 
   discard ds.sendPayload(self.getTopic(), encryptedBytes.toEnvelope(
       self.getConvoId()))
@@ -81,8 +138,19 @@ proc handleFrame*[T: ConversationStore](convo: PrivateV1, client: T,
   ## Dispatcher for Incoming `PrivateV1Frames`.
   ## Calls further processing depending on the kind of frame.
 
-  let enc = decode(bytes, EncryptedPayload).get()       # TODO: handle result
-  let frame = convo.decrypt(enc) # TODO: handle result
+  let enc = decode(bytes, EncryptedPayload).valueOr:
+    raise newException(ValueError, fmt"Failed to decode EncryptedPayload: {repr(error)}")
+
+  # TODO: Decrypt the payload
+  let (frameData, missingDeps, channelId) = convo.sdsClient.unwrapReceivedMessage(
+      enc.plaintext.payload).valueOr:
+    raise newException(ValueError, fmt"Failed to unwrap SDS message:{repr(error)}")
+
+  debug "sds unwrap", convo = convo.id(), missingDeps = missingDeps,
+      channelId = channelId
+
+  let frame = decode(frameData, PrivateV1Frame).valueOr:
+    raise newException(ValueError, "Failed to decode SdsM: " & error)
 
   if frame.sender == @(convo.owner.getPubkey().bytes()):
     notice "Self Message", convo = convo.id()
@@ -102,7 +170,7 @@ method sendMessage*(convo: PrivateV1, ds: WakuClient,
 
   try:
     let frame = PrivateV1Frame(sender: @(convo.owner.getPubkey().bytes()),
-        content: content_frame)
+        timestamp: getCurrentTimestamp(), content: content_frame)
 
     await convo.sendFrame(ds, frame)
   except Exception as e:
diff --git a/src/chat_sdk/delivery/waku_client.nim b/src/chat_sdk/delivery/waku_client.nim
index 16dab9c..f882346 100644
--- a/src/chat_sdk/delivery/waku_client.nim
+++ b/src/chat_sdk/delivery/waku_client.nim
@@ -118,7 +118,7 @@ proc buildWakuNode(cfg: WakuConfig): WakuNode =
   builder.withNetworkConfigurationDetails(ip, Port(cfg.port)).tryGet()
   let node = builder.build().tryGet()
 
-  node.mountMetadata(cfg.clusterId, @[1'u16, 2'u16]).expect("failed to mount waku metadata protocol")
+  node.mountMetadata(cfg.clusterId, cfg.shardId).expect("failed to mount waku metadata protocol")
 
   result = node
 
diff --git a/src/chat_sdk/inbox.nim b/src/chat_sdk/inbox.nim
index 7ede48b..df1ca53 100644
--- a/src/chat_sdk/inbox.nim
+++ b/src/chat_sdk/inbox.nim
@@ -72,8 +72,12 @@ proc createPrivateV1FromInvite*[T: ConversationStore](client: T,
   let destPubkey = loadPublicKeyFromBytes(invite.initiator).valueOr:
     raise newException(ValueError, "Invalid public key in intro bundle.")
 
-  let convo = initPrivateV1(client.identity(), destPubkey, "default")
+  let deliveryAckCb = proc(
+        conversation: Conversation,
+      msgId: string): Future[void] {.async.} =
+    client.notifyReadReceipt(conversation, msgId)
 
+  let convo = initPrivateV1(client.identity(), destPubkey, "default", deliveryAckCb)
   notice "Creating PrivateV1 conversation", client = client.getId(),
       topic = convo.getConvoId()
   client.addConversation(convo)
diff --git a/src/chat_sdk/types.nim b/src/chat_sdk/types.nim
index bb42ea2..6f44be7 100644
--- a/src/chat_sdk/types.nim
+++ b/src/chat_sdk/types.nim
@@ -1 +1,4 @@
 type ChatError* = string
+
+
+type MessageId* = string
diff --git a/src/chat_sdk/utils.nim b/src/chat_sdk/utils.nim
index 043075a..237f5f4 100644
--- a/src/chat_sdk/utils.nim
+++ b/src/chat_sdk/utils.nim
@@ -4,11 +4,11 @@ import crypto
 import blake2
 import strutils
 
-proc getTimestamp*(): Timestamp =
+proc getCurrentTimestamp*(): Timestamp =
     result = waku_core.getNanosecondTime(getTime().toUnix())
 
 
-proc hash_func*(s: string): string =
+proc hash_func*(s: string | seq[byte]): string =
     # This should be Blake2s but it does not exist so substituting with Blake2b
     result = getBlake2b(s, 4, "")
 
diff --git a/src/dev.nim b/src/dev.nim
index a9b767e..8db0a06 100644
--- a/src/dev.nim
+++ b/src/dev.nim
@@ -1,6 +1,191 @@
-## Utilties for development and debugging
+import chronos
+import chronicles
+import strformat
+import tables
+
+import sds
+
+import std/typetraits
+import sequtils
+
+logScope:
+  topics = "dev"
+
+type A = ref object
+  asg: string
 
 proc dir*[T](obj: T) =
   echo "Object of type: ", T
   for name, value in fieldPairs(obj):
-    echo "  ", name, ": ", value
+    if type(value) is string:
+      echo "  ", name, ": ", value
+    if type(value) is Table:
+      echo "hmmmm"
+
+proc `$`(rm: ReliabilityManager): string =
+  result = "RM"
+
+
+
+type Msg = object
+  id*: string
+  shouldDrop: bool
+  data*: seq[byte]
+
+
+
+
+proc send(rm: ReliabilityManager, channel: string, id: string, msg: seq[
+    byte]): seq[byte] =
+  result = rm.wrapOutgoingMessage(msg, id, channel).valueOr:
+    raise newException(ValueError, "Bad outgoing message")
+
+proc recv(rm: ReliabilityManager, bytes: seq[byte]) =
+  let (unwrapped, missingDeps, channelId) = rm.unwrapReceivedMessage(bytes).valueOr:
+    raise newException(ValueError, "Bad unwrap")
+  info "RECV", channel = channelId, data = unwrapped, mdeps = missingDeps
+
+
+
+proc main() {.async.} =
+
+  var messageSentCount = 0
+  let CHANNEL = "CHANNEL"
+  let msg = @[byte(1), 2, 3]
+  let msgId = "test-msg-1"
+
+  var rm = newReliabilityManager().valueOr:
+    raise newException(ValueError, fmt"SDS InitializationError")
+
+  rm.setCallbacks(
+      proc(messageId: SdsMessageID, channelId: SdsChannelID) {.gcsafe.} =
+    echo "OnMsgReady"
+    discard,
+      proc(messageId: SdsMessageID, channelId: SdsChannelID) {.gcsafe.} =
+    echo "OnMsgSent"
+    messageSentCount += 1,
+      proc(messageId: SdsMessageID, missingDeps: seq[SdsMessageID],
+          channelId: SdsChannelID) {.gcsafe.} =
+    echo "OnMissing"
+    discard,
+  )
+
+
+  let sourceMsgs = @[Msg(id: "1", shouldDrop: false, data: @[byte(1), 2, 3]),
+                Msg(id: "2", shouldDrop: true, data: @[byte(0), 5, 6]),
+                Msg(id: "3", shouldDrop: false, data: @[byte(7), 8, 9]),
+  ]
+  rm.ensureChannel(CHANNEL).isOkOr:
+    raise newException(ValueError, "Bad channel")
+
+
+  let encodedMessage = sourceMsgs.map(proc(m: Msg): seq[byte] =
+    rm.wrapOutgoingMessage(m.data, m.id, CHANNEL).valueOr:
+      raise newException(ValueError, "Bad outgoing message"))
+
+  var i = 0
+  var droppedMessages: seq[seq[byte]] = @[]
+  for x in encodedMessage:
+    if i mod 2 == 0:
+      droppedMessages.add(x)
+    inc(i)
+
+
+
+  # let droppedMessages = encodedMessage.keepIf(proc(item: seq[
+  #     byte]): bool =
+  #   items.find(item) mod 2 == 0
+  # )
+  # let droppedMessages = enumerate(encodedMessage).filter(proc(x: seq[
+  #     byte]): bool = x[0] mod 2 == 0)
+
+  for s in droppedMessages:
+    info "DROPPED", len = len(s)
+
+  for m in droppedMessages:
+    let (unwrapped, missingDeps, channelId) = rm.unwrapReceivedMessage(m).valueOr:
+      raise newException(ValueError, "Bad unwrap")
+
+    info "RECV", channel = channelId, data = unwrapped, mdeps = missingDeps
+
+
+proc messageSequence(){.async.} =
+  var messageSentCount = 0
+  let CHANNEL = "CHANNEL"
+
+
+  var raya = newReliabilityManager().valueOr:
+    raise newException(ValueError, fmt"SDS InitializationError")
+
+  var saro = newReliabilityManager().valueOr:
+    raise newException(ValueError, fmt"SDS InitializationError")
+
+  raya.setCallbacks(
+      proc(messageId: SdsMessageID, channelId: SdsChannelID) {.gcsafe.} =
+    debug "OnMsgReady", client = "raya", id = messageId
+    discard,
+      proc(messageId: SdsMessageID, channelId: SdsChannelID) {.gcsafe.} =
+    debug "OnMsgSent", client = "raya", id = messageId
+    messageSentCount += 1,
+      proc(messageId: SdsMessageID, missingDeps: seq[SdsMessageID],
+          channelId: SdsChannelID) {.gcsafe.} =
+    info "OnMissing", client = "raya", id = messageId
+    discard,
+  )
+
+  saro.setCallbacks(
+      proc(messageId: SdsMessageID, channelId: SdsChannelID) {.gcsafe.} =
+    debug "OnMsgReady", client = "saro", id = messageId
+    discard,
+      proc(messageId: SdsMessageID, channelId: SdsChannelID) {.gcsafe.} =
+    debug "OnMsgSent", client = "saro", id = messageId
+    messageSentCount += 1,
+      proc(messageId: SdsMessageID, missingDeps: seq[SdsMessageID],
+          channelId: SdsChannelID) {.gcsafe.} =
+    info "OnMissing", client = "saro", id = messageId
+    discard,
+  )
+
+  raya.ensureChannel(CHANNEL).isOkOr:
+    raise newException(ValueError, "Bad channel")
+
+  saro.ensureChannel(CHANNEL).isOkOr:
+    raise newException(ValueError, "Bad channel")
+
+
+  let s1 = saro.send(CHANNEL, "s1", @[byte(1), 1, 1])
+  raya.recv(s1)
+
+  let r1 = raya.send(CHANNEL, "r1", @[byte(2), 1, 2])
+  saro.recv(r1)
+
+  let r2 = raya.send(CHANNEL, "r2", @[byte(2), 2, 2])
+  # saro.recv(r2)
+
+  let r3 = raya.send(CHANNEL, "r3", @[byte(2), 3, 2])
+  saro.recv(r3)
+
+  let s2 = saro.send(CHANNEL, "s2", @[byte(1), 2, 1])
+  raya.recv(s2)
+
+  let s3 = saro.send(CHANNEL, "s3", @[byte(1), 3, 1])
+  raya.recv(s3)
+
+
+  let r4 = raya.send(CHANNEL, "r4", @[byte(2), 4, 2])
+  saro.recv(r4)
+  saro.recv(r2)
+
+  let r5 = raya.send(CHANNEL, "r5", @[byte(2), 5, 2])
+  saro.recv(r5)
+
+  let r6 = raya.send(CHANNEL, "r6", @[byte(2), 6, 2])
+  saro.recv(r6)
+
+  saro.recv(r4)
+  saro.recv(r3)
+
+  saro.recv(r4)
+when isMainModule:
+  waitFor messageSequence()
+  echo ">>>"
diff --git a/src/nim_chat_poc.nim b/src/nim_chat_poc.nim
index 14364c6..a207e43 100644
--- a/src/nim_chat_poc.nim
+++ b/src/nim_chat_poc.nim
@@ -9,7 +9,6 @@ import chat_sdk/utils
 
 import content_types/all
 
-
 const SELF_DEFINED = 99
 
 type ImageFrame {.proto3.} = object
@@ -69,6 +68,11 @@ proc main() {.async.} =
     await convo.sendMessage(saro.ds, initImage(
         "https://waku.org/theme/image/logo-black.svg"))
     )
+
+  saro.onReadReceipt(proc(convo: Conversation, msgId: string) {.async.} =
+    echo "    Saro -- Read Receipt for " & msgId
+  )
+
   await saro.start()
 
   var raya = newClient("Raya", cfg_raya)
@@ -82,6 +86,10 @@ proc main() {.async.} =
     echo "           ------>  Raya :: New Conversation: " & convo.id()
     await convo.sendMessage(raya.ds, initTextFrame("Hello").toContentFrame())
   )
+  raya.onReadReceipt(proc(convo: Conversation, msgId: string) {.async.} =
+    echo "    raya -- Read Receipt for " & msgId
+  )
+
   await raya.start()