diff --git a/services/tunnelbroker/src/cxx_bridge.rs b/services/tunnelbroker/src/cxx_bridge.rs
--- a/services/tunnelbroker/src/cxx_bridge.rs
+++ b/services/tunnelbroker/src/cxx_bridge.rs
@@ -31,6 +31,15 @@
     sessionID: String,
     grpcStatus: GrpcResult,
   }
+  struct SessionItem {
+    deviceID: String,
+    publicKey: String,
+    notifyToken: String,
+    deviceType: i32,
+    appVersion: String,
+    deviceOS: String,
+    isOnline: bool,
+  }
 
   unsafe extern "C++" {
     include!("tunnelbroker/src/libcpp/Tunnelbroker.h");
@@ -47,15 +56,6 @@
       deviceOS: &str,
       notifyToken: &str,
     ) -> NewSessionResult;
-    pub fn sessionSignatureHandler(deviceID: &str) -> SessionSignatureResult;
-    pub fn newSessionHandler(
-      deviceID: &str,
-      publicKey: &str,
-      signature: &str,
-      deviceType: i32,
-      deviceAppVersion: &str,
-      deviceOS: &str,
-      notifyToken: &str,
-    ) -> NewSessionResult;
+    pub fn getSessionItem(sessionID: &str) -> Result<SessionItem>;
   }
 }
diff --git a/services/tunnelbroker/src/libcpp/Tunnelbroker.h b/services/tunnelbroker/src/libcpp/Tunnelbroker.h
--- a/services/tunnelbroker/src/libcpp/Tunnelbroker.h
+++ b/services/tunnelbroker/src/libcpp/Tunnelbroker.h
@@ -24,3 +24,4 @@
     rust::Str deviceAppVersion,
     rust::Str deviceOS,
     rust::Str notifyToken);
+SessionItem getSessionItem(rust::Str sessionID);
diff --git a/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp b/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp
--- a/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp
+++ b/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp
@@ -149,77 +149,24 @@
       .grpcStatus = {.statusCode = GRPCStatusCodes::Ok}};
 }
 
-NewSessionResult newSessionHandler(
-    rust::Str deviceID,
-    rust::Str publicKey,
-    rust::Str signature,
-    int32_t deviceType,
-    rust::Str deviceAppVersion,
-    rust::Str deviceOS,
-    rust::Str notifyToken) {
-  std::shared_ptr<comm::network::database::DeviceSessionItem> deviceSessionItem;
-  std::shared_ptr<comm::network::database::SessionSignItem> sessionSignItem;
-  std::shared_ptr<comm::network::database::PublicKeyItem> publicKeyItem;
-  const std::string stringDeviceID{deviceID};
-  if (!comm::network::tools::validateDeviceID(stringDeviceID)) {
-    return NewSessionResult{
-        .grpcStatus = {
-            .statusCode = 3,
-            .errorText = "Format validation failed for deviceID"}};
+SessionItem getSessionItem(rust::Str sessionID) {
+  const std::string stringSessionID = std::string{sessionID};
+  if (!comm::network::tools::validateSessionID(stringSessionID)) {
+    throw std::invalid_argument("Invalid format for 'sessionID'");
   }
-  const std::string stringPublicKey{publicKey};
-  const std::string newSessionID = comm::network::tools::generateUUID();
-  try {
-    sessionSignItem = comm::network::database::DatabaseManager::getInstance()
-                          .findSessionSignItem(stringDeviceID);
-    if (sessionSignItem == nullptr) {
-      return NewSessionResult{
-          .grpcStatus = {
-              .statusCode = 5,
-              .errorText = "Session signature request not found for deviceID"}};
-    }
-    publicKeyItem = comm::network::database::DatabaseManager::getInstance()
-                        .findPublicKeyItem(stringDeviceID);
-    if (publicKeyItem == nullptr) {
-      std::shared_ptr<comm::network::database::PublicKeyItem> newPublicKeyItem =
-          std::make_shared<comm::network::database::PublicKeyItem>(
-              stringDeviceID, stringPublicKey);
-      comm::network::database::DatabaseManager::getInstance().putPublicKeyItem(
-          *newPublicKeyItem);
-    } else if (stringPublicKey != publicKeyItem->getPublicKey()) {
-      return NewSessionResult{
-          .grpcStatus = {
-              .statusCode = 7,
-              .errorText = "The public key doesn't match for deviceID"}};
-    }
-    const std::string verificationMessage = sessionSignItem->getSign();
-    if (!comm::network::crypto::rsaVerifyString(
-            stringPublicKey, verificationMessage, std::string{signature})) {
-      return NewSessionResult{
-          .grpcStatus = {
-              .statusCode = 7,
-              .errorText =
-                  "Signature for the verification message is not valid"}};
-    }
-    comm::network::database::DatabaseManager::getInstance()
-        .removeSessionSignItem(stringDeviceID);
-
-    deviceSessionItem =
-        std::make_shared<comm::network::database::DeviceSessionItem>(
-            newSessionID,
-            stringDeviceID,
-            stringPublicKey,
-            std::string{notifyToken},
-            deviceType,
-            std::string{deviceAppVersion},
-            std::string{deviceOS});
-    comm::network::database::DatabaseManager::getInstance().putSessionItem(
-        *deviceSessionItem);
-  } catch (std::runtime_error &e) {
-    LOG(ERROR) << "gRPC: "
-               << "Error while processing 'NewSession' request: " << e.what();
-    return NewSessionResult{
-        .grpcStatus = {.statusCode = 13, .errorText = e.what()}};
+  std::shared_ptr<comm::network::database::DeviceSessionItem> sessionItem =
+      comm::network::database::DatabaseManager::getInstance().findSessionItem(
+          stringSessionID);
+  if (sessionItem == nullptr) {
+    throw std::invalid_argument(
+        "No sessions found for 'sessionID': " + stringSessionID);
   }
-  return NewSessionResult{.sessionID = newSessionID};
+  return SessionItem{
+      .deviceID = sessionItem->getDeviceID(),
+      .publicKey = sessionItem->getPubKey(),
+      .notifyToken = sessionItem->getNotifyToken(),
+      .deviceType = static_cast<int>(sessionItem->getDeviceType()),
+      .appVersion = sessionItem->getAppVersion(),
+      .deviceOS = sessionItem->getDeviceOs(),
+      .isOnline = sessionItem->getIsOnline()};
 }
diff --git a/services/tunnelbroker/src/server/mod.rs b/services/tunnelbroker/src/server/mod.rs
--- a/services/tunnelbroker/src/server/mod.rs
+++ b/services/tunnelbroker/src/server/mod.rs
@@ -1,12 +1,13 @@
 use super::constants;
 use super::cxx_bridge::ffi::{
-  newSessionHandler, sessionSignatureHandler, GRPCStatusCodes,
+  getSessionItem, newSessionHandler, sessionSignatureHandler, GRPCStatusCodes,
 };
 use anyhow::Result;
 use futures::Stream;
 use std::pin::Pin;
-use tonic::transport::Server;
-use tonic::{Request, Response, Status, Streaming};
+use tokio::sync::mpsc;
+use tokio_stream::wrappers::ReceiverStream;
+use tonic::{transport::Server, Request, Response, Status, Streaming};
 use tunnelbroker::tunnelbroker_service_server::{
   TunnelbrokerService, TunnelbrokerServiceServer,
 };
@@ -76,11 +77,33 @@
       dyn Stream<Item = Result<tunnelbroker::MessageToClient, Status>> + Send,
     >,
   >;
+
   async fn messages_stream(
     &self,
-    _request: Request<Streaming<tunnelbroker::MessageToTunnelbroker>>,
+    request: Request<Streaming<tunnelbroker::MessageToTunnelbroker>>,
   ) -> Result<Response<Self::MessagesStreamStream>, Status> {
-    Err(Status::unimplemented("Not implemented yet"))
+    let session_id = match request.metadata().get("sessionID") {
+      Some(metadata_session_id) => metadata_session_id
+        .to_str()
+        .expect("metadata session id was not valid UTF8")
+        .to_string(),
+      None => {
+        return Err(Status::invalid_argument(
+          "No 'sessionID' in metadata was provided",
+        ))
+      }
+    };
+    let _session_item = match getSessionItem(&session_id) {
+      Ok(database_item) => database_item,
+      Err(err) => return Err(Status::unauthenticated(err.what())),
+    };
+
+    let (_tx, rx) = mpsc::channel(constants::GRPC_TX_QUEUE_SIZE);
+
+    let output_stream = ReceiverStream::new(rx);
+    Ok(Response::new(
+      Box::pin(output_stream) as Self::MessagesStreamStream
+    ))
   }
 
   // These empty old API handlers are deprecated and should be removed.