diff --git a/client/inc/logic/client_reactor.h b/client/inc/logic/client_reactor.h
new file mode 100644
index 0000000..13b7363
--- /dev/null
+++ b/client/inc/logic/client_reactor.h
@@ -0,0 +1,34 @@
+#pragma once
+
+#include "logic/message_handler.h"
+#include "messages.pb.h"
+#include "services.grpc.pb.h"
+#include <QObject>
+#include <condition_variable>
+#include <grpcpp/support/client_callback.h>
+#include <grpcpp/support/status.h>
+#include <memory>
+
+class Reactor : public QObject,
+                public grpc::ClientBidiReactor<chat::chatMsg, chat::chatMsg> {
+  Q_OBJECT
+public:
+  explicit Reactor(chat::Chat::Stub *);
+  void OnWriteDone(bool ok) override;
+  void OnReadDone(bool ok) override;
+  void OnDone(const grpc::Status &s) override;
+  grpc::Status Await();
+  void SendMessage(const chat::chatMsg &msg);
+  bool IsConnected() const;
+  std::shared_ptr<MessageHandler> getHandler();
+
+private:
+  chat::Chat::Stub *m_stub;
+  grpc::ClientContext m_context;
+  chat::chatMsg m_msg;
+  std::shared_ptr<MessageHandler> m_handler;
+  std::mutex m_mutex;
+  std::condition_variable m_cv;
+  bool m_done = false;
+  grpc::Status m_status;
+};
diff --git a/client/inc/logic/message_handler.h b/client/inc/logic/message_handler.h
new file mode 100644
index 0000000..82999ac
--- /dev/null
+++ b/client/inc/logic/message_handler.h
@@ -0,0 +1,14 @@
+#pragma once
+
+#include "messages.pb.h"
+#include <QObject>
+
+class MessageHandler : public QObject {
+  Q_OBJECT
+public:
+  MessageHandler(QObject *parent = nullptr) {}
+  void emitMessageReceived(const chat::chatMsg &message);
+
+signals:
+  void messageReceived(const chat::chatMsg &message);
+};
diff --git a/client/inc/models/message.h b/client/inc/models/message.h
index 4178437..edade3f 100644
--- a/client/inc/models/message.h
+++ b/client/inc/models/message.h
@@ -5,13 +5,13 @@
 
 class Message {
 public:
-  Message(int, QDateTime, QString);
+  Message(QString, QDateTime, QString);
   ~Message() {}
 
   QString toString() const;
 
 private:
-  int m_userId;
+  QString m_userId;
   QDateTime m_timestamp;
   QString m_content;
 };
diff --git a/client/inc/ui/mainwindow.h b/client/inc/ui/mainwindow.h
index 0fb9abf..c316604 100644
--- a/client/inc/ui/mainwindow.h
+++ b/client/inc/ui/mainwindow.h
@@ -1,7 +1,10 @@
 #pragma once
 
+#include "logic/client_reactor.h"
+#include "messages.pb.h"
 #include "models/chatroom.h"
 #include <QMainWindow>
+#include <memory>
 
 QT_BEGIN_NAMESPACE
 namespace Ui {
@@ -17,9 +20,12 @@ public:
   ~MainWindow();
 
 private:
+  void sendMsg(const QString &);
+
   Ui::MainWindow *ui;
   Chatroom m_chatroom;
+  std::unique_ptr<Reactor> m_reactor;
 
 public slots:
-  void receiveMsg(QString &);
+  void receiveMsg(const chat::chatMsg &);
 };
diff --git a/client/src/logic/client_reactor.cpp b/client/src/logic/client_reactor.cpp
new file mode 100644
index 0000000..8fe07ca
--- /dev/null
+++ b/client/src/logic/client_reactor.cpp
@@ -0,0 +1,61 @@
+#include "logic/client_reactor.h"
+#include "messages.pb.h"
+#include "services.grpc.pb.h"
+#include <QObject>
+#include <memory>
+
+Reactor::Reactor(chat::Chat::Stub *stub) : m_stub(stub) {
+  m_stub->async()->sendMsg(&m_context, this);
+
+  m_handler = std::make_shared<MessageHandler>();
+
+  StartRead(&m_msg);
+  StartCall();
+}
+
+void Reactor::OnWriteDone(bool ok) {
+  if (!ok) {
+    std::cerr << "Error: write failed" << std::endl;
+  }
+}
+
+void Reactor::OnReadDone(bool ok) {
+  if (ok) {
+    m_handler->emitMessageReceived(m_msg);
+    std::cout << "Received message from: " << m_msg.userid()
+              << " content: " << m_msg.message() << std::endl;
+    StartRead(&m_msg);
+  } else {
+    std::cout << "Server finished sending" << std::endl;
+  }
+}
+
+void Reactor::OnDone(const grpc::Status &status) {
+  m_status = status;
+  {
+    std::lock_guard<std::mutex> lock(m_mutex);
+    m_done = true;
+  }
+  m_cv.notify_one();
+  if (!status.ok()) {
+    std::cerr << "Error: " << status.error_message() << std::endl;
+  }
+  std::cout << "Server finished sending" << std::endl;
+}
+
+grpc::Status Reactor::Await() {
+  std::unique_lock<std::mutex> lock(m_mutex);
+  m_cv.wait(lock, [this] { return m_done; });
+  return m_status;
+}
+
+void Reactor::SendMessage(const chat::chatMsg &msg) {
+  static chat::chatMsg writeMsg;
+  writeMsg.CopyFrom(msg);
+  StartWrite(&writeMsg);
+  std::cout << "Sent message: " << msg.message();
+}
+
+bool Reactor::IsConnected() const { return !m_done; }
+
+std::shared_ptr<MessageHandler> Reactor::getHandler() { return m_handler; }
diff --git a/client/src/logic/message_handler.cpp b/client/src/logic/message_handler.cpp
new file mode 100644
index 0000000..cfbdf82
--- /dev/null
+++ b/client/src/logic/message_handler.cpp
@@ -0,0 +1,5 @@
+#include "logic/message_handler.h"
+
+void MessageHandler::emitMessageReceived(const chat::chatMsg &msg) {
+  emit messageReceived(msg);
+}
diff --git a/client/src/models/message.cpp b/client/src/models/message.cpp
index 7cc01c8..74dbc1b 100644
--- a/client/src/models/message.cpp
+++ b/client/src/models/message.cpp
@@ -1,6 +1,6 @@
 #include "models/message.h"
 
-Message::Message(int userId, QDateTime timestamp, QString content)
+Message::Message(QString userId, QDateTime timestamp, QString content)
     : m_userId(userId), m_timestamp(timestamp), m_content(content) {}
 
 QString Message::toString() const {
diff --git a/client/src/ui/mainwindow.cpp b/client/src/ui/mainwindow.cpp
index 7debe25..715f909 100644
--- a/client/src/ui/mainwindow.cpp
+++ b/client/src/ui/mainwindow.cpp
@@ -1,20 +1,45 @@
 #include "ui/mainwindow.h"
+#include "logic/client_reactor.h"
+#include "messages.pb.h"
 #include "ui_mainwindow.h"
+#include <grpcpp/create_channel.h>
+#include <grpcpp/security/credentials.h>
+#include <memory>
 
 MainWindow::MainWindow(QWidget *parent)
     : QMainWindow(parent), ui(new Ui::MainWindow) {
   ui->setupUi(this);
+  auto channel = grpc::CreateChannel("localhost:50051",
+                                     grpc::InsecureChannelCredentials());
+  auto stub = chat::Chat::NewStub(channel);
+
+  m_reactor = std::make_unique<Reactor>(stub.get());
 
   connect(ui->sendButton, &QPushButton::clicked, this, [this]() {
     auto msg = ui->inputText->toPlainText();
-    receiveMsg(msg);
+    if (!msg.isEmpty()) {
+      sendMsg(msg);
+      ui->inputText->clear();
+    }
   });
+  connect(m_reactor->getHandler().get(), &MessageHandler::messageReceived, this,
+          &MainWindow::receiveMsg);
 }
 
 MainWindow::~MainWindow() { delete ui; }
 
-void MainWindow::receiveMsg(QString &msg) {
-  Message message(0, QDateTime::currentDateTime(), msg);
+void MainWindow::sendMsg(const QString &msg) {
+  if (m_reactor && m_reactor->IsConnected()) {
+    chat::chatMsg chatMsg;
+    chatMsg.set_message(msg.toStdString());
+    m_reactor->SendMessage(chatMsg);
+  }
+}
+
+void MainWindow::receiveMsg(const chat::chatMsg &chatMsg) {
+  auto userId = QString::fromStdString(chatMsg.userid());
+  auto content = QString::fromStdString(chatMsg.message());
+  Message message(userId, QDateTime::currentDateTime(), content);
   m_chatroom.addMessage(message);
   ui->outputText->setText(m_chatroom.getMessagesString());
 }
diff --git a/server/CMakeLists.txt b/server/CMakeLists.txt
index acd7d5e..27cde48 100644
--- a/server/CMakeLists.txt
+++ b/server/CMakeLists.txt
@@ -1,6 +1,9 @@
 cmake_minimum_required(VERSION 3.23)
 project(chat_server LANGUAGES CXX)
 
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
 file(GLOB_RECURSE SOURCES "src/*.ui" "src/*.cpp" "inc/*.h" "res/*.qrc")
 
 add_executable(chat_server
diff --git a/server/inc/logic/service.h b/server/inc/logic/service.h
index ee5bdec..6aae342 100644
--- a/server/inc/logic/service.h
+++ b/server/inc/logic/service.h
@@ -5,6 +5,7 @@
 #include "services.grpc.pb.h"
 #include <grpcpp/server_context.h>
 #include <grpcpp/support/server_callback.h>
+#include <map>
 
 class Service : public chat::Chat::CallbackService {
 public:
@@ -14,7 +15,7 @@ public:
   void sendToAll(const chat::chatMsg &msg);
 
 private:
-  std::vector<ChatReactor *> m_clients;
+  std::map<std::string, ChatReactor *> m_clients;
   absl::Mutex m_mu;
   std::vector<chat::chatMsg> m_messages ABSL_GUARDED_BY(m_mu);
 };
diff --git a/server/src/logic/reactor.cpp b/server/src/logic/reactor.cpp
index ed28b96..3b91f7e 100644
--- a/server/src/logic/reactor.cpp
+++ b/server/src/logic/reactor.cpp
@@ -9,6 +9,7 @@ ChatReactor::ChatReactor(Service *service, absl::Mutex *mu,
 
 void ChatReactor::OnReadDone(bool ok) {
   if (ok) {
+    std::cout << "Received message: " << m_msg.message() << std::endl;
     m_mu->lock();
     m_messages->push_back(m_msg);
     m_mu->unlock();
diff --git a/server/src/logic/service.cpp b/server/src/logic/service.cpp
index 8dd51cb..be21766 100644
--- a/server/src/logic/service.cpp
+++ b/server/src/logic/service.cpp
@@ -1,21 +1,29 @@
 #include "logic/service.h"
 #include "logic/reactor.h"
+#include <cstdlib>
+#include <format>
+#include <utility>
 
 Service::~Service() {
-  for (auto *client : m_clients) {
-    delete client;
+  for (auto client : m_clients) {
+    delete client.second;
   }
 }
 
 grpc::ServerBidiReactor<chat::chatMsg, chat::chatMsg> *
 Service::sendMsg(grpc::CallbackServerContext *context) {
   auto newClient = new ChatReactor(this, &m_mu, &m_messages);
-  m_clients.push_back(newClient);
+  std::string newId = std::format("user_{}", std::rand());
+  m_clients.insert(std::make_pair(newId, newClient));
+  std::cout << "New client: " << newId << std::endl;
   return newClient;
 }
 
 void Service::sendToAll(const chat::chatMsg &msg) {
-  for (auto *client : m_clients) {
-    client->StartWrite(&msg);
+  std::cout << "Relay message to: ";
+  for (auto client : m_clients) {
+    std::cout << client.first << " ";
+    client.second->StartWrite(&msg);
   }
+  std::cout << std::endl;
 }