diff --git a/WD7UVN_HFT_2023241.Client/CRUD.cs b/WD7UVN_HFT_2023241.Client/CRUD.cs
new file mode 100644
index 0000000..81e42da
--- /dev/null
+++ b/WD7UVN_HFT_2023241.Client/CRUD.cs
@@ -0,0 +1,778 @@
+using System;
+using WD7UVN_HFT_2023241.Models;
+
+namespace WD7UVN_HFT_2023241.Client
+{
+    public class Read
+    {
+        public static void Customer()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the customer's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            Customer c = RestService.Get<Customer>(input, "/api/Customer/");
+            Console.WriteLine("Name: " + c.NAME);
+            Console.WriteLine("ID: " + c.ID);
+            Console.WriteLine("Email: " + c.EMAIL);
+            Console.WriteLine("Phone: " + c.PHONE);
+            Console.WriteLine("ID of used service: " + c.SERVICE_ID);
+        }
+
+        public static void Employee()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the employee's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            Employee c = RestService.Get<Employee>(input, "/api/Employee/");
+            Console.WriteLine("Name: " + c.NAME);
+            Console.WriteLine("ID: " + c.ID);
+            Console.WriteLine("Email: " + c.EMAIL);
+            Console.WriteLine("Phone: " + c.PHONE);
+            Console.WriteLine("Maintainer team's ID: " + c.MAINTAINER_ID);
+            Console.WriteLine("Manager's ID: " + c.MANAGER_ID);
+        }
+
+        public static void Service()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the service's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            Service c = RestService.Get<Service>(input, "/api/Service/");
+            Console.WriteLine("Name: " + c.NAME);
+            Console.WriteLine("ID: " + c.ID);
+            Console.WriteLine("Account: " + c.ACCOUNT);
+            Console.WriteLine("IP: " + c.IP);
+            Console.WriteLine("Port: " + c.PORT);
+            Console.WriteLine("Notes: " + c.NOTES);
+            Console.WriteLine("Service domain: " + c.SERVICE_DOMAIN);
+            Console.WriteLine("Version: " + c.VERSION);
+            Console.WriteLine("Maintainer team's ID: " + c.MAINTAINER_ID);
+        }   
+
+        public static void MaintainerTeam()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the team's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            MaintainerTeam c = RestService.Get<MaintainerTeam>(input, "/api/MaintainerTeam/");
+            Console.WriteLine("Name: " + c.NAME);
+            Console.WriteLine("ID: " + c.ID);
+            Console.WriteLine("Email: " + c.EMAIL);
+            Console.WriteLine("Leader's ID: " + c.LEADER_ID);
+        } 
+    }
+
+    public class ReadAll
+    {
+        public static void Customer()
+        {
+            Console.Clear();
+
+            foreach (Customer c in RestService.Get<Customer>("/api/Customer"))
+            {
+                Console.WriteLine("Name: " + c.NAME);
+                Console.WriteLine("ID: " + c.ID);
+                Console.WriteLine("Email: " + c.EMAIL);
+                Console.WriteLine("Phone: " + c.PHONE);
+                Console.WriteLine("ID of used service: " + c.SERVICE_ID);
+            }
+        }
+
+        public static void Employee()
+        {
+            Console.Clear();
+
+            foreach (Employee c in RestService.Get<Employee>("/api/Employee"))
+            {
+                Console.WriteLine("Name: " + c.NAME);
+                Console.WriteLine("ID: " + c.ID);
+                Console.WriteLine("Email: " + c.EMAIL);
+                Console.WriteLine("Phone: " + c.PHONE);
+                Console.WriteLine("Maintainer team's ID: " + c.MAINTAINER_ID);
+                Console.WriteLine("Manager's ID: " + c.MANAGER_ID);
+            }
+        }
+
+        public static void Service()
+        {
+            Console.Clear();
+
+            foreach (Service c in RestService.Get<Service>("/api/Service"))
+            {
+                Console.WriteLine("Name: " + c.NAME);
+                Console.WriteLine("ID: " + c.ID);
+                Console.WriteLine("Account: " + c.ACCOUNT);
+                Console.WriteLine("IP: " + c.IP);
+                Console.WriteLine("Port: " + c.PORT);
+                Console.WriteLine("Notes: " + c.NOTES);
+                Console.WriteLine("Service domain: " + c.SERVICE_DOMAIN);
+                Console.WriteLine("Version: " + c.VERSION);
+                Console.WriteLine("Maintainer team's ID: " + c.MAINTAINER_ID);
+            }
+        }   
+
+        public static void MaintainerTeam()
+        {
+            Console.Clear();
+
+            foreach (MaintainerTeam c in RestService.Get<MaintainerTeam>("/api/MaintainerTeam"))
+            {
+                Console.WriteLine("Name: " + c.NAME);
+                Console.WriteLine("ID: " + c.ID);
+                Console.WriteLine("Email: " + c.EMAIL);
+                Console.WriteLine("Leader's ID: " + c.LEADER_ID);
+            }
+        } 
+    }
+
+    public class Create
+    {
+        public static void Customer()
+        {
+            Console.Clear();
+
+            while (true)
+            {
+                try
+                {
+                    Console.Write("ID (integer): ");
+                    int id = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("Name (text): ");
+                    string name = Console.ReadLine();
+
+                    Console.Write("Email (text): ");
+                    string email = Console.ReadLine();
+
+                    Console.Write("Phone (text): ");
+                    string phone = Console.ReadLine();
+
+                    Console.Write("ServiceID (integer): ");
+                    int service_id = Convert.ToInt32(Console.ReadLine());
+
+                    Customer c = new Customer()
+                    {
+                        ID = id,
+                        NAME = name,
+                        EMAIL = email,
+                        PHONE = phone,
+                        SERVICE_ID = service_id
+                    };
+
+                    RestService.Put<Customer>(c, "/api/Customer");
+
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("Invalid format!");
+                }
+            }
+        }
+
+        public static void Employee()
+        {
+            Console.Clear();
+
+            while (true)
+            {
+                try
+                {
+                    Console.Write("ID (integer): ");
+                    int id = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("Name (text): ");
+                    string name = Console.ReadLine();
+
+                    Console.Write("Email (text): ");
+                    string email = Console.ReadLine();
+
+                    Console.Write("Phone (text): ");
+                    string phone = Console.ReadLine();
+
+                    Console.Write("Team ID (integer): ");
+                    int maintainer_id = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("Manager's ID (integer): ");
+                    int manager_id = Convert.ToInt32(Console.ReadLine());
+
+                    Employee c = new Employee()
+                    {
+                        ID = id,
+                        NAME = name,
+                        EMAIL = email,
+                        PHONE = phone,
+                        MAINTAINER_ID = maintainer_id,
+                        MANAGER_ID = manager_id
+                    };
+
+                    RestService.Put<Employee>(c, "/api/Employee");
+
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("Invalid format!");
+                }
+            }
+        }
+
+        public static void Service()
+        {
+            Console.Clear();
+
+            while (true)
+            {
+                try
+                {
+                    Console.Write("ID (integer): ");
+                    int id = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("Name (text): ");
+                    string name = Console.ReadLine();
+
+                    Console.Write("Maintainer team's ID (integer): ");
+                    int maintainer_id = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("Version (integer): ");
+                    int version = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("IP (text): ");
+                    string ip = Console.ReadLine();
+
+                    Console.Write("Port (integer): ");
+                    int port = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("Service account (text): ");
+                    string account = Console.ReadLine();
+
+                    Console.Write("Service domain (text): ");
+                    string domain = Console.ReadLine();
+
+                    Console.Write("Note(s) (text): ");
+                    string notes = Console.ReadLine();
+
+                    Service c = new Service()
+                    {
+                        ID = id,
+                        NAME = name,
+                        MAINTAINER_ID = maintainer_id,
+                        PORT = port,
+                        IP = ip,
+                        SERVICE_DOMAIN = domain,
+                        ACCOUNT = account,
+                        NOTES = notes,
+                        VERSION = version
+                    };
+
+                    RestService.Put<Service>(c, "/api/Service");
+
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("Invalid format!");
+                }
+            }
+        }   
+
+        public static void MaintainerTeam()
+        {
+            Console.Clear();
+
+            while (true)
+            {
+                try
+                {
+                    Console.Write("ID (integer): ");
+                    int id = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("Name (text): ");
+                    string name = Console.ReadLine();
+
+                    Console.Write("Email (text): ");
+                    string email = Console.ReadLine();
+
+                    Console.Write("Leader's ID (integer): ");
+                    int leader_id = Convert.ToInt32(Console.ReadLine());
+
+                    MaintainerTeam c = new MaintainerTeam()
+                    {
+                        ID = id,
+                        NAME = name,
+                        LEADER_ID = leader_id,
+                        EMAIL = email
+                    };
+
+                    RestService.Put<MaintainerTeam>(c, "/api/MaintainerTeam");
+
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("Invalid format!");
+                }
+            }
+        } 
+    }
+
+    public class Update
+    {
+        public static void Customer()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the customer's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            Customer c = RestService.Get<Customer>(input, "/api/Customer/");
+
+            Console.WriteLine("Name: " + c.NAME);
+            Console.WriteLine("Email: " + c.EMAIL);
+            Console.WriteLine("Phone: " + c.PHONE);
+            Console.WriteLine("ID of used service: " + c.SERVICE_ID);
+
+            Console.WriteLine("Now you can modify these fields, except for the ID.");
+
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Name (text): ");
+                    string name = Console.ReadLine();
+
+                    Console.Write("Email (text): ");
+                    string email = Console.ReadLine();
+
+                    Console.Write("Phone (text): ");
+                    string phone = Console.ReadLine();
+
+                    Console.Write("ServiceID (integer): ");
+                    int service_id = Convert.ToInt32(Console.ReadLine());
+
+                    c = new Customer()
+                    {
+                        ID = input,
+                        NAME = name,
+                        EMAIL = email,
+                        PHONE = phone,
+                        SERVICE_ID = service_id
+                    };
+
+                    RestService.Post<Customer>(c, "/api/Customer");
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("Invalid format!");
+                }
+            }
+        }
+
+        public static void Employee()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the employee's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            Employee c = RestService.Get<Employee>(input, "/api/Employee/");
+
+            Console.WriteLine("Name: " + c.NAME);
+            Console.WriteLine("ID: " + c.ID);
+            Console.WriteLine("Email: " + c.EMAIL);
+            Console.WriteLine("Phone: " + c.PHONE);
+            Console.WriteLine("Maintainer team's ID: " + c.MAINTAINER_ID);
+            Console.WriteLine("Manager's ID: " + c.MANAGER_ID);
+
+            Console.WriteLine("Now you can modify these fields, except for the ID.");
+
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Name (text): ");
+                    string name = Console.ReadLine();
+
+                    Console.Write("Email (text): ");
+                    string email = Console.ReadLine();
+
+                    Console.Write("Phone (text): ");
+                    string phone = Console.ReadLine();
+
+                    Console.Write("Team ID (integer): ");
+                    int maintainer_id = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("Manager's ID (integer): ");
+                    int manager_id = Convert.ToInt32(Console.ReadLine());
+
+                    c = new Employee()
+                    {
+                        ID = input,
+                        NAME = name,
+                        EMAIL = email,
+                        PHONE = phone,
+                        MANAGER_ID = manager_id,
+                        MAINTAINER_ID = maintainer_id
+                    };
+
+                    RestService.Post<Employee>(c, "/api/Employee");
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("Invalid format!");
+                }
+            }
+        }
+
+        public static void Service()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the service's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            Service c = RestService.Get<Service>(input, "/api/Service/");
+
+            Console.WriteLine("Name: " + c.NAME);
+            Console.WriteLine("ID: " + c.ID);
+            Console.WriteLine("Account: " + c.ACCOUNT);
+            Console.WriteLine("IP: " + c.IP);
+            Console.WriteLine("Port: " + c.PORT);
+            Console.WriteLine("Notes: " + c.NOTES);
+            Console.WriteLine("Service domain: " + c.SERVICE_DOMAIN);
+            Console.WriteLine("Version: " + c.VERSION);
+            Console.WriteLine("Maintainer team's ID: " + c.MAINTAINER_ID);
+            Console.WriteLine("Now you can modify these fields, except for the ID.");
+
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Name (text): ");
+                    string name = Console.ReadLine();
+
+                    Console.Write("Maintainer team's ID (integer): ");
+                    int maintainer_id = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("Version (integer): ");
+                    int version = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("IP (text): ");
+                    string ip = Console.ReadLine();
+
+                    Console.Write("Port (integer): ");
+                    int port = Convert.ToInt32(Console.ReadLine());
+
+                    Console.Write("Service account (text): ");
+                    string account = Console.ReadLine();
+
+                    Console.Write("Service domain (text): ");
+                    string domain = Console.ReadLine();
+
+                    Console.Write("Note(s) (text): ");
+                    string notes = Console.ReadLine();
+
+                    c = new Service()
+                    {
+                        ID = input,
+                        NAME = name,
+                        MAINTAINER_ID = maintainer_id,
+                        PORT = port,
+                        IP = ip,
+                        SERVICE_DOMAIN = domain,
+                        ACCOUNT = account,
+                        NOTES = notes,
+                        VERSION = version
+                    };
+
+                    RestService.Post<Service>(c, "/api/Service");
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("Invalid format!");
+                }
+            }
+        }   
+
+        public static void MaintainerTeam()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the service's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            MaintainerTeam c = RestService.Get<MaintainerTeam>(input, "/api/MaintainerTeam/");
+
+            Console.WriteLine("Name: " + c.NAME);
+            Console.WriteLine("ID: " + c.ID);
+            Console.WriteLine("Email: " + c.EMAIL);
+            Console.WriteLine("Leader's ID: " + c.LEADER_ID);
+
+            Console.WriteLine("Now you can modify these fields, except for the ID.");
+
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Name (text): ");
+                    string name = Console.ReadLine();
+
+                    Console.Write("Email (text): ");
+                    string email = Console.ReadLine();
+
+                    Console.Write("Leader's ID (integer): ");
+                    int leader_id = Convert.ToInt32(Console.ReadLine());
+
+                    c = new MaintainerTeam()
+                    {
+                        ID = input,
+                        NAME = name,
+                        LEADER_ID = leader_id,
+                        EMAIL = email
+                    };
+
+                    RestService.Post<MaintainerTeam>(c, "/api/MaintainerTeam");
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("Invalid format!");
+                }
+            }
+        } 
+    }
+
+    public class Delete
+    {
+        public static void Customer()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the customer's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            try
+            {
+                RestService.Delete(input, "/api/Customer/");
+                Console.WriteLine("Successfully deleted Customer with ID {0}", input);
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine("Uh-oh...");
+                Console.WriteLine(e.Message);
+            }
+        }
+
+        public static void Employee()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the employee's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            try
+            {
+                RestService.Delete(input, "/api/Employee/");
+                Console.WriteLine("Successfully deleted Employee with ID {0}", input);
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine("Uh-oh...");
+                Console.WriteLine(e.Message);
+            }
+        }
+
+        public static void Service()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the service's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            try
+            {
+                RestService.Delete(input, "/api/Service/");
+                Console.WriteLine("Successfully deleted Service with ID {0}", input);
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine("Uh-oh...");
+                Console.WriteLine(e.Message);
+            }
+        }   
+
+        public static void MaintainerTeam()
+        {
+            Console.Clear();
+
+            int input;
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Enter a number for the team's ID: ");
+                    input = Convert.ToInt32(Console.ReadLine());
+                    break;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number.");
+                }
+            }
+
+            try
+            {
+                RestService.Delete(input, "/api/MaintainerTeam/");
+                Console.WriteLine("Successfully deleted MaintainerTeam with ID {0}", input);
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine("Uh-oh...");
+                Console.WriteLine(e.Message);
+            }
+        } 
+    }
+}
\ No newline at end of file
diff --git a/WD7UVN_HFT_2023241.Client/NonCRUD.cs b/WD7UVN_HFT_2023241.Client/NonCRUD.cs
new file mode 100644
index 0000000..45e2049
--- /dev/null
+++ b/WD7UVN_HFT_2023241.Client/NonCRUD.cs
@@ -0,0 +1,216 @@
+using System;
+using System.Linq;
+using WD7UVN_HFT_2023241.Models;
+
+namespace WD7UVN_HFT_2023241.Client
+{
+    public class NonCRUD 
+    {
+
+        public static void WhoMaintainsService()
+        {
+            foreach (Service s in RestService.Get<Service>("/api/Service"))
+            {
+                Console.WriteLine("Service: " + s.NAME);
+                Console.WriteLine("ID: " + s.ID);
+            }
+
+            int id = 1;
+            bool flag = true;
+            while (flag)
+            {
+                try
+                {
+                    Console.Write("Your choice: ");
+                    id = Convert.ToInt32(Console.ReadLine());
+                    flag = false;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number");
+                }
+            }
+
+            IQueryable<Employee> res = RestService.WhoMaintainsService(id);
+            if (res.Count() != 0)
+            {
+                foreach (Employee e in res)
+                {
+                    Console.WriteLine("Név: " + e.NAME);
+                    Console.WriteLine("ID: " + e.ID);
+                    Console.WriteLine("Email: " + e.EMAIL);
+                    Console.WriteLine("Phone: " + e.PHONE);
+                    Console.WriteLine("Manager's ID: " + e.MANAGER_ID);
+                }
+            }
+            else
+            {
+                Console.WriteLine("No such database entry was found :/");
+            }
+        }
+
+        public static void WhoUsesService()
+        {
+            foreach (Service s in RestService.Get<Service>("/api/Service"))
+            {
+                Console.WriteLine("Service: " + s.NAME);
+                Console.WriteLine("ID: " + s.ID);
+            }
+
+            int id = 1;
+            bool flag = true;
+            while (flag)
+            {
+                try
+                {
+                    Console.Write("Your choice: ");
+                    id = Convert.ToInt32(Console.ReadLine());
+                    flag = false;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number");
+                }
+            }
+
+            IQueryable<Customer> res = RestService.WhoUsesService(id);
+            if (res.Count() != 0)
+            {
+                foreach (Customer c in res)
+                {
+                    Console.WriteLine("Name: " + c.NAME);
+                    Console.WriteLine("ID: " + c.ID);
+                    Console.WriteLine("Email: " + c.EMAIL);
+                    Console.WriteLine("Phone: " + c.PHONE);
+                }
+            }
+            else
+            {
+                Console.WriteLine("No such database entry was found :/");
+            }
+        }
+
+        public static void WhoIsResponsibleForService()
+        {
+            foreach (Service s in RestService.Get<Service>("/api/Service"))
+            {
+                Console.WriteLine("Service: " + s.NAME);
+                Console.WriteLine("ID: " + s.ID);
+            }
+
+            int id = 1;
+            bool flag = true;
+            while (flag)
+            {
+                try
+                {
+                    Console.Write("Your choice: ");
+                    id = Convert.ToInt32(Console.ReadLine());
+                    flag = false;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number");
+                }
+            }
+
+            Employee? res = RestService.WhoIsResponsibleForService(id);
+            if (res != null)
+            {
+                Console.WriteLine("Name: " + res.NAME);
+                Console.WriteLine("ID: " + res.ID);
+                Console.WriteLine("Email: " + res.EMAIL);
+                Console.WriteLine("Phone: " + res.PHONE);
+                Console.WriteLine("Maintainer team ID: " + res.MAINTAINER_ID);
+            }
+            else
+            {
+                Console.WriteLine("No such database entry was found :/");
+            }
+        }
+
+        public static void GetSubordinates()
+        {
+            foreach (Employee e in RestService.Get<Employee>("/api/Employee"))
+            {
+                Console.WriteLine("Name: " + e.NAME);
+                Console.WriteLine("ID: " + e.ID);
+            }
+
+            int id = 1;
+            bool flag = true;
+            while (flag)
+            {
+                try
+                {
+                    Console.Write("Your choice: ");
+                    id = Convert.ToInt32(Console.ReadLine());
+                    flag = false;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number");
+                }
+            }
+
+            IQueryable<Employee> res = RestService.GetSubordinates(id);
+            if (res.Count() != 0)
+            {
+                foreach (Employee e in res)
+                {
+                    Console.WriteLine("Név: " + e.NAME);
+                    Console.WriteLine("ID: " + e.ID);
+                    Console.WriteLine("Email: " + e.EMAIL);
+                    Console.WriteLine("Phone: " + e.PHONE);
+                    Console.WriteLine("Maintainer team ID: " + e.MAINTAINER_ID);
+                }
+            }
+            else
+            {
+                Console.WriteLine("No such database entry was found :/");
+            }
+        }
+
+        public static void WhoWorksInMaintainerTeam()
+        {
+            foreach(MaintainerTeam m in RestService.Get<MaintainerTeam>("/api/MaintainerTeam"))
+            {
+                Console.WriteLine("Team name: " + m.NAME);
+                Console.WriteLine("ID: " + m.ID + "\n\n");
+            }
+
+            int id = 1;
+            bool flag = true;
+            while (flag)
+            {
+                try
+                {
+                    Console.Write("Your choice: ");
+                    id = Convert.ToInt32(Console.ReadLine());
+                    flag = false;
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number");
+                }
+            }
+
+            IQueryable<Employee> res = RestService.WhoWorksInMaintainerTeam(id);
+            if (res.Count() != 0)
+            {
+                foreach (Employee e in RestService.WhoWorksInMaintainerTeam(id))
+                {
+                    Console.WriteLine("Név: " + e.NAME);
+                    Console.WriteLine("ID: " + e.ID);
+                    Console.WriteLine("Email: " + e.EMAIL);
+                    Console.WriteLine("Phone: " + e.PHONE);
+                    Console.WriteLine("Manager's ID: " + e.MANAGER_ID);
+                }
+            }
+            else
+            {
+                Console.WriteLine("No such database entry was found :/");
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/WD7UVN_HFT_2023241.Client/Program.cs b/WD7UVN_HFT_2023241.Client/Program.cs
index 91c832b..cffc223 100644
--- a/WD7UVN_HFT_2023241.Client/Program.cs
+++ b/WD7UVN_HFT_2023241.Client/Program.cs
@@ -1,62 +1,178 @@
 using System;
-using WD7UVN_HFT_2023241.Models;
-using System.Collections.Generic;
 
 namespace WD7UVN_HFT_2023241.Client
 {
     class Program
     {
+        static bool FLAG = true;
+        static RestService rest = new RestService();
+
         static void Main(string[] args)
         {
-            RestService rest = new RestService();
+            ActionMenuHandler();
+        }
 
-            Console.WriteLine("All employees:\n");
-            List<Employee> employeeList = rest.Get<Employee>("/api/Employee/");
-			foreach (Employee e in employeeList)
-			{
-				Console.WriteLine(
-					e.NAME +
-					": " +
-					e.ID
-				);
-			}
+        static void ActionMenuHandler()
+        {
+            while (FLAG)
+            {
+                int choice = ActionMenu();
+                if (choice == 6)
+                {
+                    NonCRUDMenuHandler();
+                }
+                else if (choice == 0)
+                {
+                    FLAG = false;
+                }
+                else if (1 <= choice && choice <= 5)
+                {
+                    switch (TypeSelectorMenu())
+                    {
+                        case 1:
+                            if (choice == 1) { Read.Employee(); }
+                            else if (choice == 2) { ReadAll.Employee(); }
+                            else if (choice == 3) { Create.Employee(); }
+                            else if (choice == 4) { Update.Employee(); }
+                            else if (choice == 5) { Delete.Employee(); }
+                            break;
+                        case 2:
+                            if (choice == 1) { Read.Customer(); }
+                            else if (choice == 2) { ReadAll.Customer(); }
+                            else if (choice == 3) { Create.Customer(); }
+                            else if (choice == 4) { Update.Customer(); }
+                            else if (choice == 5) { Delete.Customer(); }
+                            break;
+                        case 3:
+                            if (choice == 1) { Read.Service(); }
+                            else if (choice == 2) { ReadAll.Service(); }
+                            else if (choice == 3) { Create.Service(); }
+                            else if (choice == 4) { Update.Service(); }
+                            else if (choice == 5) { Delete.Service(); }
+                            break;
+                        case 4:
+                            if (choice == 1) { Read.MaintainerTeam(); }
+                            else if (choice == 2) { ReadAll.MaintainerTeam(); }
+                            else if (choice == 3) { Create.MaintainerTeam(); }
+                            else if (choice == 4) { Update.MaintainerTeam(); }
+                            else if (choice == 5) { Delete.MaintainerTeam(); }
+                            break;
+                    }
+                }
+            }
+        }
 
-            Console.WriteLine("\n\nAll customers:\n");
-            List<Customer> customerList = rest.Get<Customer>("/api/Customer/");
-			foreach (Customer c in customerList)
-			{
-				Console.WriteLine(
-					c.NAME +
-					": " +
-					c.ID
-				);
-			}
+        static int TypeSelectorMenu()
+        {
+            Console.Clear();
+            Console.WriteLine("1.) Employee");
+            Console.WriteLine("2.) Customer");
+            Console.WriteLine("3.) Service");
+            Console.WriteLine("4.) MaintainerTeam");
 
-            Console.WriteLine("\n\nMaintainer teams:\n");
-            List<MaintainerTeam> maintainerTeamList = rest.Get<MaintainerTeam>("/api/MaintainerTeam/");
-			foreach (MaintainerTeam m in maintainerTeamList)
-			{
-				Console.WriteLine(
-					m.NAME + 
-					": " +
-					m.ID
-				);
-			}
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Your choice: ");
+                    return Convert.ToInt32(Console.ReadLine());
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number");
+                }
+            }
 
-            Console.WriteLine("\n\nMaintained services:\n");
-            List<Service> serviceList = rest.Get<Service>("/api/Service/");
-			foreach (Service s in serviceList)
-			{
-				Console.WriteLine(
-					s.NAME +
-					": " +
-					s.ID +
-					" -> " +
-					s.IP
-					+ ":" +
-					s.PORT
-				);
-			}
+        }
+
+        static int ReadMenuHandler()
+        {
+            Console.Clear();
+            Console.WriteLine("1.) ");
+
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Your choice: ");
+                    return Convert.ToInt32(Console.ReadLine());
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number");
+                }
+            }
+        }
+
+        static void NonCRUDMenuHandler()
+        {
+            switch (NonCRUDMenu())
+            {
+                case 1:
+                    NonCRUD.WhoWorksInMaintainerTeam();
+                    break;
+                case 2:
+                    NonCRUD.GetSubordinates();
+                    break;
+                case 3:
+                    NonCRUD.WhoUsesService();
+                    break;
+                case 4:
+                    NonCRUD.WhoIsResponsibleForService();
+                    break;
+                case 5:
+                    NonCRUD.WhoMaintainsService();
+                    break;
+            }
+        }
+
+
+        static int NonCRUDMenu()
+        {
+            Console.Clear();
+            Console.WriteLine("1.) Who works in specified maintainer team?");
+            Console.WriteLine("2.) Get manager's subordinates");
+            Console.WriteLine("3.) Which client(s) use(s) specified service?");
+            Console.WriteLine("4.) Who (which manager) is responsible for a specified service?");
+            Console.WriteLine("5.) Get all employees who maintain a specified service");
+
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Your choice: ");
+                    return Convert.ToInt32(Console.ReadLine());
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number");
+                }
+            }
+        }
+
+        static int ActionMenu()
+        {
+            Console.Clear();
+            Console.WriteLine("1.) Read");
+            Console.WriteLine("2.) ReadAll");
+            Console.WriteLine("3.) Create");
+            Console.WriteLine("4.) Update");
+            Console.WriteLine("5.) Delete");
+            Console.WriteLine("6.) Non-CRUD");
+            Console.WriteLine("0.) Exit");
+
+            while (true)
+            {
+                try
+                {
+                    Console.Write("Your choice: ");
+                    return Convert.ToInt32(Console.ReadLine());
+                }
+                catch (FormatException)
+                {
+                    Console.WriteLine("You must enter a number");
+                }
+            }
         }
     }
 }
diff --git a/WD7UVN_HFT_2023241.Client/RestService.cs b/WD7UVN_HFT_2023241.Client/RestService.cs
index 5b8a0d1..6cc097c 100644
--- a/WD7UVN_HFT_2023241.Client/RestService.cs
+++ b/WD7UVN_HFT_2023241.Client/RestService.cs
@@ -1,14 +1,16 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Net;
 using System.Net.Http;
 using System.Net.Security;
+using WD7UVN_HFT_2023241.Models;
 
 namespace WD7UVN_HFT_2023241.Client
 {
     class RestService
     {
-        HttpClient client;
+        private static HttpClient client;
 
         public RestService(string baseurl = "https://localhost:5001", string pingableEndpoint = "/swagger")
         {
@@ -64,7 +66,7 @@ namespace WD7UVN_HFT_2023241.Client
 
         }
 
-        public List<T> Get<T>(string endpoint)
+        public static List<T> Get<T>(string endpoint)
         {
             List<T> items = new List<T>();
             HttpResponseMessage response = client.GetAsync(endpoint).GetAwaiter().GetResult();
@@ -80,7 +82,7 @@ namespace WD7UVN_HFT_2023241.Client
             return items;
         }
 
-        public T GetSingle<T>(string endpoint)
+        public static T GetSingle<T>(string endpoint)
         {
             T item = default(T);
             HttpResponseMessage response = client.GetAsync(endpoint).GetAwaiter().GetResult();
@@ -96,7 +98,7 @@ namespace WD7UVN_HFT_2023241.Client
             return item;
         }
 
-        public T Get<T>(int id, string endpoint)
+        public static T Get<T>(int id, string endpoint)
         {
             T item = default(T);
             HttpResponseMessage response = client.GetAsync(endpoint + "/" + id.ToString()).GetAwaiter().GetResult();
@@ -112,7 +114,7 @@ namespace WD7UVN_HFT_2023241.Client
             return item;
         }
 
-        public void Post<T>(T item, string endpoint)
+        public static void Post<T>(T item, string endpoint)
         {
             HttpResponseMessage response =
                 client.PostAsJsonAsync(endpoint, item).GetAwaiter().GetResult();
@@ -125,7 +127,7 @@ namespace WD7UVN_HFT_2023241.Client
             response.EnsureSuccessStatusCode();
         }
 
-        public void Delete(int id, string endpoint)
+        public static void Delete(int id, string endpoint)
         {
             HttpResponseMessage response =
                 client.DeleteAsync(endpoint + "/" + id.ToString()).GetAwaiter().GetResult();
@@ -139,7 +141,7 @@ namespace WD7UVN_HFT_2023241.Client
             response.EnsureSuccessStatusCode();
         }
 
-        public void Put<T>(T item, string endpoint)
+        public static void Put<T>(T item, string endpoint)
         {
             HttpResponseMessage response =
                 client.PutAsJsonAsync(endpoint, item).GetAwaiter().GetResult();
@@ -153,6 +155,85 @@ namespace WD7UVN_HFT_2023241.Client
             response.EnsureSuccessStatusCode();
         }
 
+        public static IQueryable<Employee> WhoWorksInMaintainerTeam(int id)
+        {
+            IQueryable<Employee> item = default(IQueryable<Employee>);
+            HttpResponseMessage response = client.GetAsync("/api/WhoWorksInMaintainerTeam/" + id.ToString()).GetAwaiter().GetResult();
+            if (response.IsSuccessStatusCode)
+            {
+                item = response.Content.ReadAsAsync<IQueryable<Employee>>().GetAwaiter().GetResult();
+            }
+            else
+            {
+                var error = response.Content.ReadAsAsync<RestExceptionInfo>().GetAwaiter().GetResult();
+                throw new ArgumentException(error.Msg);
+            }
+            return item;
+        }
+
+        public static IQueryable<Employee> GetSubordinates(int id)
+        {
+            IQueryable<Employee> item = default(IQueryable<Employee>);
+            HttpResponseMessage response = client.GetAsync("/api/GetSubordinates/" + id.ToString()).GetAwaiter().GetResult();
+            if (response.IsSuccessStatusCode)
+            {
+                item = response.Content.ReadAsAsync<IQueryable<Employee>>().GetAwaiter().GetResult();
+            }
+            else
+            {
+                var error = response.Content.ReadAsAsync<RestExceptionInfo>().GetAwaiter().GetResult();
+                throw new ArgumentException(error.Msg);
+            }
+            return item;
+        }
+
+        public static IQueryable<Customer> WhoUsesService(int id)
+        {
+            IQueryable<Customer> item = default(IQueryable<Customer>);
+            HttpResponseMessage response = client.GetAsync("/api/WhoUsesService/" + id.ToString()).GetAwaiter().GetResult();
+            if (response.IsSuccessStatusCode)
+            {
+                item = response.Content.ReadAsAsync<IQueryable<Customer>>().GetAwaiter().GetResult();
+            }
+            else
+            {
+                var error = response.Content.ReadAsAsync<RestExceptionInfo>().GetAwaiter().GetResult();
+                throw new ArgumentException(error.Msg);
+            }
+            return item;
+        }
+
+        public static Employee WhoIsResponsibleForService(int id)
+        {
+            Employee item = default(Employee);
+            HttpResponseMessage response = client.GetAsync("/api/WhoIsResponsibleForService/" + id.ToString()).GetAwaiter().GetResult();
+            if (response.IsSuccessStatusCode)
+            {
+                item = response.Content.ReadAsAsync<Employee>().GetAwaiter().GetResult();
+            }
+            else
+            {
+                var error = response.Content.ReadAsAsync<RestExceptionInfo>().GetAwaiter().GetResult();
+                throw new ArgumentException(error.Msg);
+            }
+            return item;
+        }
+
+        public static IQueryable<Employee> WhoMaintainsService(int id)
+        {
+            IQueryable<Employee> item = default(IQueryable<Employee>);
+            HttpResponseMessage response = client.GetAsync("/api/WhoMaintainsService/" + id.ToString()).GetAwaiter().GetResult();
+            if (response.IsSuccessStatusCode)
+            {
+                item = response.Content.ReadAsAsync<IQueryable<Employee>>().GetAwaiter().GetResult();
+            }
+            else
+            {
+                var error = response.Content.ReadAsAsync<RestExceptionInfo>().GetAwaiter().GetResult();
+                throw new ArgumentException(error.Msg);
+            }
+            return item;
+        }
     }
     public class RestExceptionInfo
     {