diff --git a/C#api/ApiRequestHandler.cs b/C#api/ApiRequestHandler.cs
deleted file mode 100644
index d162334..0000000
--- a/C#api/ApiRequestHandler.cs
+++ /dev/null
@@ -1,1356 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Net;
-using System.Text;
-using Models;
-
-using Newtonsoft.Json;
-
-public class ApiRequestHandler
-{
-    public void HandleGet(HttpListenerRequest request, HttpListenerResponse response)
-    {
-        string apiKey = request.Headers["API_KEY"];
-        var user = AuthProvider.GetUser(apiKey);
-
-        if (user == null)
-        {
-            response.StatusCode = (int)HttpStatusCode.Unauthorized;
-            response.Close();
-            return;
-        }
-
-        try
-        {
-            string[] path = request.Url.AbsolutePath.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
-            if (path.Length > 2 && path[0] == "api" && path[1] == "v1")
-            {
-                HandleGetVersion1(path[2..], user, response);
-            }
-            else
-            {
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-            }
-        }
-        catch (Exception)
-        {
-            response.StatusCode = (int)HttpStatusCode.InternalServerError;
-            response.Close();
-        }
-    }
-
-    private void HandleGetVersion1(string[] path, User user, HttpListenerResponse response)
-    {
-        if (!AuthProvider.HasAccess(user, path[0], "get"))
-        {
-            response.StatusCode = (int)HttpStatusCode.Forbidden;
-            response.Close();
-            return;
-        }
-
-        switch (path[0])
-        {
-            case "warehouses":
-                HandleWarehouses(path, response);
-                break;
-            case "locations":
-                HandleLocations(path, response);
-                break;
-            case "transfers":
-                HandleTransfers(path, response);
-                break;
-            case "items":
-                HandleItems(path, response);
-                break;
-            case "item_lines":
-                HandleItemLines(path, response);
-                break;
-            case "item_groups":
-                HandleItemGroups(path, response);
-                break;
-            case "item_types":
-                HandleItemTypes(path, response);
-                break;
-            case "inventories":
-                HandleInventories(path, response);
-                break;
-            case "suppliers":
-                HandleSuppliers(path, response);
-                break;
-            case "orders":
-                HandleOrders(path, response);
-                break;
-            case "clients":
-                HandleClients(path, response);
-                break;
-            case "shipments":
-                HandleShipments(path, response);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleWarehouses(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var warehouses = DataProvider.fetch_warehouse_pool().GetWarehouses();
-                SendResponse(response, warehouses);
-                break;
-            case 2:
-                int warehouseId = int.Parse(path[1]);
-                var warehouse = DataProvider.fetch_warehouse_pool().GetWarehouse(warehouseId);
-                SendResponse(response, warehouse);
-                break;
-            case 3 when path[2] == "locations":
-                warehouseId = int.Parse(path[1]);
-                var locations = DataProvider.fetch_location_pool().GetLocationsInWarehouse(warehouseId);
-                SendResponse(response, locations);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleLocations(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var locations = DataProvider.fetch_location_pool().GetLocations();
-                SendResponse(response, locations);
-                break;
-            case 2:
-                int locationId = int.Parse(path[1]);
-                var location = DataProvider.fetch_location_pool().GetLocation(locationId);
-                SendResponse(response, location);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleTransfers(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var transfers = DataProvider.fetch_transfer_pool().GetTransfers();
-                SendResponse(response, transfers);
-                break;
-            case 2:
-                int transferId = int.Parse(path[1]);
-                var transfer = DataProvider.fetch_transfer_pool().GetTransfer(transferId);
-                SendResponse(response, transfer);
-                break;
-            case 3 when path[2] == "items":
-                transferId = int.Parse(path[1]);
-                var items = DataProvider.fetch_transfer_pool().GetItemsInTransfer(transferId);
-                SendResponse(response, items);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleItems(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var items = DataProvider.fetch_item_pool().GetItems();
-                SendResponse(response, items);
-                break;
-            case 2:
-                var itemId = path[1];
-                var item = DataProvider.fetch_item_pool().GetItem(itemId);
-                SendResponse(response, item);
-                break;
-            case 3 when path[2] == "inventory":
-                itemId = path[1];
-                var inventories = DataProvider.fetch_inventory_pool().GetInventoriesForItem(itemId);
-                SendResponse(response, inventories);
-                break;
-            case 4 when path[2] == "inventory" && path[3] == "totals":
-                itemId = path[1];
-                var totals = DataProvider.fetch_inventory_pool().GetInventoryTotalsForItem(itemId);
-                SendResponse(response, totals);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleItemLines(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var itemLines = DataProvider.fetch_itemline_pool().GetItemLines();
-                SendResponse(response, itemLines);
-                break;
-            case 2:
-                int itemLineId = int.Parse(path[1]);
-                var itemLine = DataProvider.fetch_itemline_pool().GetItemLine(itemLineId);
-                SendResponse(response, itemLine);
-                break;
-            case 3 when path[2] == "items":
-                itemLineId = int.Parse(path[1]);
-                var items = DataProvider.fetch_item_pool().GetItemsForItemLine(itemLineId);
-                SendResponse(response, items);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleItemGroups(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var itemGroups = DataProvider.fetch_itemgroup_pool().GetItemGroups();
-                SendResponse(response, itemGroups);
-                break;
-            case 2:
-                int itemGroupId = int.Parse(path[1]);
-                var itemGroup = DataProvider.fetch_itemgroup_pool().GetItemGroup(itemGroupId);
-                SendResponse(response, itemGroup);
-                break;
-            case 3 when path[2] == "items":
-                itemGroupId = int.Parse(path[1]);
-                var items = DataProvider.fetch_item_pool().GetItemsForItemGroup(itemGroupId);
-                SendResponse(response, items);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleItemTypes(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var itemTypes = DataProvider.fetch_itemtype_pool().GetItemTypes();
-                SendResponse(response, itemTypes);
-                break;
-            case 2:
-                int itemTypeId = int.Parse(path[1]);
-                var itemType = DataProvider.fetch_itemtype_pool().GetItemType(itemTypeId);
-                SendResponse(response, itemType);
-                break;
-            case 3 when path[2] == "items":
-                itemTypeId = int.Parse(path[1]);
-                var items = DataProvider.fetch_item_pool().GetItemsForItemType(itemTypeId);
-                SendResponse(response, items);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleInventories(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var inventories = DataProvider.fetch_inventory_pool().GetInventories();
-                SendResponse(response, inventories);
-                break;
-            case 2:
-                int inventoryId = int.Parse(path[1]);
-                var inventory = DataProvider.fetch_inventory_pool().GetInventory(inventoryId);
-                SendResponse(response, inventory);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleSuppliers(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var suppliers = DataProvider.fetch_supplier_pool().GetSuppliers();
-                SendResponse(response, suppliers);
-                break;
-            case 2:
-                int supplierId = int.Parse(path[1]);
-                var supplier = DataProvider.fetch_supplier_pool().GetSupplier(supplierId);
-                SendResponse(response, supplier);
-                break;
-            case 3 when path[2] == "items":
-                supplierId = int.Parse(path[1]);
-                var items = DataProvider.fetch_item_pool().GetItemsForSupplier(supplierId);
-                SendResponse(response, items);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleOrders(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var orders = DataProvider.fetch_order_pool().GetOrders();
-                SendResponse(response, orders);
-                break;
-            case 2:
-                int orderId = int.Parse(path[1]);
-                var order = DataProvider.fetch_order_pool().GetOrder(orderId);
-                SendResponse(response, order);
-                break;
-            case 3 when path[2] == "items":
-                orderId = int.Parse(path[1]);
-                var items = DataProvider.fetch_order_pool().GetItemsInOrder(orderId);
-                SendResponse(response, items);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleClients(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var clients = DataProvider.fetch_client_pool().GetClients();
-                SendResponse(response, clients);
-                break;
-            case 2:
-                int clientId = int.Parse(path[1]);
-                var client = DataProvider.fetch_client_pool().GetClient(clientId);
-                SendResponse(response, client);
-                break;
-            case 3 when path[2] == "orders":
-                clientId = int.Parse(path[1]);
-                var orders = DataProvider.fetch_order_pool().GetOrdersForClient(clientId);
-                SendResponse(response, orders);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandleShipments(string[] path, HttpListenerResponse response)
-    {
-        switch (path.Length)
-        {
-            case 1:
-                var shipments = DataProvider.fetch_shipment_pool().GetShipments();
-                SendResponse(response, shipments);
-                break;
-            case 2:
-                int shipmentId = int.Parse(path[1]);
-                var shipment = DataProvider.fetch_shipment_pool().GetShipment(shipmentId);
-                SendResponse(response, shipment);
-                break;
-            case 3 when path[2] == "orders":
-                shipmentId = int.Parse(path[1]);
-                var orders = DataProvider.fetch_order_pool().GetOrdersInShipment(shipmentId);
-                SendResponse(response, orders);
-                break;
-            case 3 when path[2] == "items":
-                shipmentId = int.Parse(path[1]);
-                var items = DataProvider.fetch_shipment_pool().GetItemsInShipment(shipmentId);
-                SendResponse(response, items);
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    public void HandleDelete(HttpListenerRequest request, HttpListenerResponse response)
-    {
-        string apiKey = request.Headers["API_KEY"];
-        var user = AuthProvider.GetUser(apiKey);
-
-        if (user == null)
-        {
-            response.StatusCode = (int)HttpStatusCode.Unauthorized;
-            response.Close();
-            return;
-        }
-
-        try
-        {
-            string[] path = request.Url.AbsolutePath.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
-            if (path.Length > 2 && path[0] == "api" && path[1] == "v1")
-            {
-                HandleDeleteVersion1(path[2..], user, response);
-            }
-            else
-            {
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-            }
-        }
-        catch (Exception)
-        {
-            response.StatusCode = (int)HttpStatusCode.InternalServerError;
-            response.Close();
-        }
-    }
-
-    public void HandlePost(HttpListenerRequest request, HttpListenerResponse response)
-    {
-        string apiKey = request.Headers["API_KEY"];
-        var user = AuthProvider.GetUser(apiKey);
-
-        if (user == null)
-        {
-            response.StatusCode = (int)HttpStatusCode.Unauthorized;
-            response.Close();
-            return;
-        }
-
-        try
-        {
-            string[] path = request.Url.AbsolutePath.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
-            if (path.Length > 2 && path[0] == "api" && path[1] == "v1")
-            {
-                HandlePostVersion1(path[2..], user, request, response);
-            }
-            else
-            {
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-            }
-        }
-        catch (Exception)
-        {
-            response.StatusCode = (int)HttpStatusCode.InternalServerError;
-            response.Close();
-        }
-    }
-
-    public void HandlePut(HttpListenerRequest request, HttpListenerResponse response)
-    {
-        string apiKey = request.Headers["API_KEY"];
-        var user = AuthProvider.GetUser(apiKey);
-
-        if (user == null)
-        {
-            response.StatusCode = (int)HttpStatusCode.Unauthorized;
-            response.Close();
-            return;
-        }
-
-        try
-        {
-            string[] path = request.Url.AbsolutePath.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
-            if (path.Length > 2 && path[0] == "api" && path[1] == "v1")
-            {
-                HandlePutVersion1(path[2..], user, request, response);
-            }
-            else
-            {
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-            }
-        }
-        catch (Exception)
-        {
-            response.StatusCode = (int)HttpStatusCode.InternalServerError;
-            response.Close();
-        }
-    }
-
-
-    private void HandlePostVersion1(string[] path, User user, HttpListenerRequest request, HttpListenerResponse response)
-    {
-        if (!AuthProvider.HasAccess(user, path[0], "post"))
-        {
-            response.StatusCode = (int)HttpStatusCode.Forbidden;
-            response.Close();
-            return;
-        }
-
-        int contentLength = (int)request.ContentLength64;
-        byte[] buffer = new byte[contentLength];
-        request.InputStream.Read(buffer, 0, contentLength);
-        string postData = Encoding.UTF8.GetString(buffer);
-
-        bool check;
-        switch (path[0])
-        {
-            case "warehouses":
-                var newWarehouse = JsonConvert.DeserializeObject<Warehouse>(postData);
-                if (newWarehouse.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_warehouse_pool().AddWarehouse(newWarehouse);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_warehouse_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            case "locations":
-                var newLocation = JsonConvert.DeserializeObject<Location>(postData);
-                if (newLocation.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_location_pool().AddLocation(newLocation);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_location_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            case "transfers":
-                var newTransfer = JsonConvert.DeserializeObject<Transfer>(postData);
-                if (newTransfer.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_transfer_pool().AddTransfer(newTransfer);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_transfer_pool().Save();
-                var notificationSystem = new NotificationSystem();
-                notificationSystem.Push($"Scheduled batch transfer {newTransfer.Id}");
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            case "items":
-                var newItem = JsonConvert.DeserializeObject<Item>(postData);
-                if (newItem.Uid == null)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_item_pool().AddItem(newItem);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_item_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            case "item_lines":
-                var newItemLine = JsonConvert.DeserializeObject<ItemLine>(postData);
-                if (newItemLine.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_itemline_pool().AddItemline(newItemLine);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_itemline_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            case "item_types":
-                var newItemType = JsonConvert.DeserializeObject<ItemType>(postData);
-                if (newItemType.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_itemtype_pool().AddItemtype(newItemType);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_itemtype_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            case "item_groups":
-                var newItemGroup = JsonConvert.DeserializeObject<ItemGroup>(postData);
-                if (newItemGroup.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_itemgroup_pool().AddItemGroup(newItemGroup);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_itemgroup_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            case "inventories":
-                var newInventory = JsonConvert.DeserializeObject<Inventory>(postData);
-                if (newInventory.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_inventory_pool().AddInventory(newInventory);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_inventory_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            case "suppliers":
-                var newSupplier = JsonConvert.DeserializeObject<Supplier>(postData);
-                if (newSupplier.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_supplier_pool().AddSupplier(newSupplier);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_supplier_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            case "orders":
-                var newOrder = JsonConvert.DeserializeObject<Order>(postData);
-                if (newOrder.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_order_pool().AddOrder(newOrder);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_order_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            case "clients":
-                var newClient = JsonConvert.DeserializeObject<Client>(postData);
-                if (newClient.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_client_pool().AddClient(newClient);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_client_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            case "shipments":
-                var newShipment = JsonConvert.DeserializeObject<Shipment>(postData);
-                if (newShipment.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_shipment_pool().AddShipment(newShipment);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID in Body already exists in data";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_shipment_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.Created;
-                response.Close();
-                break;
-
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                break;
-        }
-    }
-
-    private void HandlePutVersion1(string[] path, User user, HttpListenerRequest request, HttpListenerResponse response)
-    {
-        if (!AuthProvider.HasAccess(user, path[0], "put"))
-        {
-            response.StatusCode = (int)HttpStatusCode.Forbidden;
-            response.Close();
-            return;
-        }
-
-        int contentLength = (int)request.ContentLength64;
-        byte[] buffer = new byte[contentLength];
-        request.InputStream.Read(buffer, 0, contentLength);
-        string putData = Encoding.UTF8.GetString(buffer);
-
-        bool check;
-
-        switch (path[0])
-        {
-            case "warehouses":
-                int warehouseId = int.Parse(path[1]);
-                var updatedWarehouse = JsonConvert.DeserializeObject<Warehouse>(putData);
-                if (updatedWarehouse.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_warehouse_pool().UpdateWarehouse(warehouseId, updatedWarehouse);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_warehouse_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.OK;
-                break;
-
-            case "locations":
-                int locationId = int.Parse(path[1]);
-                var updatedLocation = JsonConvert.DeserializeObject<Location>(putData);
-                if (updatedLocation.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_location_pool().UpdateLocation(locationId, updatedLocation);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_location_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.OK;
-                break;
-
-            case "transfers":
-                if (path.Length == 2) // Update transfer
-            {
-                int transferId = int.Parse(path[1]);
-                var updatedTransfer = JsonConvert.DeserializeObject<Transfer>(putData);
-                if (updatedTransfer.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_transfer_pool().UpdateTransfer(transferId, updatedTransfer);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_transfer_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.OK;
-                response.Close();
-            }
-            else if (path.Length == 3 && path[2] == "commit") // Commit transfer
-            {
-                int transferId = int.Parse(path[1]);
-                var transfer = DataProvider.fetch_transfer_pool().GetTransfer(transferId);
-                if (transfer is null)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                if (transfer.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                // Update inventories based on transfer items
-                foreach (var item in transfer.Items)
-                {
-                    var inventories = DataProvider.fetch_inventory_pool().GetInventoriesForItem(item.Item_Id);
-                    foreach (var inventory in inventories)
-                    {
-                        if (transfer.Transfer_From is null) break;
-                        if (inventory.Locations.Contains((int)transfer.Transfer_From))
-                        {
-                            inventory.Total_On_Hand -= item.Amount;
-                        }
-                        else if (inventory.Locations.Contains((int)transfer.Transfer_To))
-                        {
-                            inventory.Total_On_Hand += item.Amount;
-                        }
-                        DataProvider.fetch_inventory_pool().UpdateInventory(inventory.Id, inventory);
-                    }
-                }
-                transfer.Transfer_Status = "Processed";
-                check = DataProvider.fetch_transfer_pool().UpdateTransfer(transferId, transfer);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                // Notify processing completion
-                var notificationSystem = new NotificationSystem();
-                notificationSystem.Push($"Processed batch transfer with id: {transfer.Id}");
-                DataProvider.fetch_transfer_pool().Save();
-                DataProvider.fetch_inventory_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.OK;
-                response.Close();
-            }
-                break;
-
-            case "items":
-                string itemId = path[1];
-                var updatedItem = JsonConvert.DeserializeObject<Item>(putData);
-                if (updatedItem.Uid == null)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_item_pool().UpdateItem(itemId, updatedItem);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_item_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.OK;
-                break;
-
-            case "item_lines":
-                int itemLineId = int.Parse(path[1]);
-                var updatedItemLine = JsonConvert.DeserializeObject<ItemLine>(putData);
-                if (updatedItemLine.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_itemline_pool().UpdateItemline(itemLineId, updatedItemLine);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_itemline_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.OK;
-                break;
-
-            case "item_types":
-                int itemTypeId = int.Parse(path[1]);
-                var updatedItemType = JsonConvert.DeserializeObject<ItemType>(putData);
-                if (updatedItemType.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_itemtype_pool().UpdateItemtype(itemTypeId, updatedItemType);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_itemtype_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.OK;
-                break;
-
-            case "item_groups":
-                int itemGroupId = int.Parse(path[1]);
-                var updatedItemGroup = JsonConvert.DeserializeObject<ItemGroup>(putData);
-                if (updatedItemGroup.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_itemgroup_pool().UpdateItemGroup(itemGroupId, updatedItemGroup);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_itemgroup_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.OK;
-                break;
-
-            case "inventories":
-                int inventoryId = int.Parse(path[1]);
-                var updatedInventory = JsonConvert.DeserializeObject<Inventory>(putData);
-                if (updatedInventory.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_inventory_pool().UpdateInventory(inventoryId, updatedInventory);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_inventory_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.OK;
-                break;
-
-            case "suppliers":
-                int supplierId = int.Parse(path[1]);
-                var updatedSupplier = JsonConvert.DeserializeObject<Supplier>(putData);
-                if (updatedSupplier.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_supplier_pool().UpdateSupplier(supplierId, updatedSupplier);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_supplier_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.OK;
-                break;
-
-            case "orders":
-                if (path.Length == 2) // Update order
-                {
-                    int orderId = int.Parse(path[1]);
-                    var updatedOrder = JsonConvert.DeserializeObject<Order>(putData);
-                    if (updatedOrder.Id == -10)
-                    {
-                        response.StatusCode = (int)HttpStatusCode.BadRequest;
-                        response.StatusDescription = "ID not given in body";
-                        response.Close();
-                        return;
-                    }
-                    check = DataProvider.fetch_order_pool().UpdateOrder(orderId, updatedOrder);
-                    if (!check)
-                    {
-                        response.StatusCode = (int)HttpStatusCode.NotFound;
-                        response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                        response.Close();
-                        return;
-                    }
-                    DataProvider.fetch_order_pool().Save();
-                    response.StatusCode = (int)HttpStatusCode.OK;
-                    response.Close();
-                }
-                else if (path.Length == 3 && path[2] == "items") // Update items in order
-                {
-                    int orderId = int.Parse(path[1]);
-                    var updatedItems = JsonConvert.DeserializeObject<List<Item>>(putData);
-                    if (updatedItems.Any(x => x.Uid == null))
-                    {
-                        response.StatusCode = (int)HttpStatusCode.BadRequest;
-                        response.StatusDescription = "ID not given (everywhere) in body";
-                        response.Close();
-                        return;
-                    }
-                    DataProvider.fetch_order_pool().UpdateItemsInOrder(orderId, updatedItems);
-                    DataProvider.fetch_order_pool().Save();
-                    response.StatusCode = (int)HttpStatusCode.OK;
-                    response.Close();
-                }
-                else
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.Close();
-                }
-                break;
-
-            case "clients":
-                int clientId = int.Parse(path[1]);
-                var updatedClient = JsonConvert.DeserializeObject<Client>(putData);
-                if (updatedClient.Id == -10)
-                {
-                    response.StatusCode = (int)HttpStatusCode.BadRequest;
-                    response.StatusDescription = "ID not given in body";
-                    response.Close();
-                    return;
-                }
-                check = DataProvider.fetch_client_pool().UpdateClient(clientId, updatedClient);
-                if (!check)
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                    response.Close();
-                    return;
-                }
-                DataProvider.fetch_client_pool().Save();
-                response.StatusCode = (int)HttpStatusCode.OK;
-                break;
-
-            case "shipments":
-                if (path.Length == 2) // Update shipment
-                {
-                    int shipmentId = int.Parse(path[1]);
-                    var updatedShipment = JsonConvert.DeserializeObject<Shipment>(putData);
-                    if (updatedShipment.Id == -10)
-                    {
-                        response.StatusCode = (int)HttpStatusCode.BadRequest;
-                        response.StatusDescription = "ID not given in body";
-                        response.Close();
-                        return;
-                    }
-                    check = DataProvider.fetch_shipment_pool().UpdateShipment(shipmentId, updatedShipment);
-                    if (!check)
-                    {
-                        response.StatusCode = (int)HttpStatusCode.NotFound;
-                        response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                        response.Close();
-                        return;
-                    }
-                    DataProvider.fetch_shipment_pool().Save();
-                    response.StatusCode = (int)HttpStatusCode.OK;
-                    response.Close();
-                }
-                else if (path.Length == 3 && path[2] == "orders") // Update orders in shipment
-                {
-                    int shipmentId = int.Parse(path[1]);
-                    var updatedOrders = JsonConvert.DeserializeObject<List<Order>>(putData);
-                    if (updatedOrders.Any(x => x.Id == -10))
-                    {
-                        response.StatusCode = (int)HttpStatusCode.BadRequest;
-                        response.StatusDescription = "ID not given (everywhere) in body";
-                        response.Close();
-                        return;
-                    }
-                    if (DataProvider.fetch_shipment_pool().GetShipment(shipmentId) == null)
-                    {
-                        response.StatusCode = (int)HttpStatusCode.NotFound;
-                        response.StatusDescription = "No data for given ID";
-                        response.Close();
-                        return;
-                    }
-                    DataProvider.fetch_order_pool().UpdateOrdersInShipment(shipmentId, updatedOrders);
-                    DataProvider.fetch_order_pool().Save();
-                    response.StatusCode = (int)HttpStatusCode.OK;
-                    response.Close();
-                }
-                else if (path.Length == 3 && path[2] == "items") // Update items in shipment
-                {
-                    int shipmentId = int.Parse(path[1]);
-                    var updatedItems = JsonConvert.DeserializeObject<List<Item>>(putData);
-                    if (updatedItems.Any(x => x.Uid == null))
-                    {
-                        response.StatusCode = (int)HttpStatusCode.BadRequest;
-                        response.StatusDescription = "ID not given (everywhere) in body";
-                        response.Close();
-                        return;
-                    }
-                    if (DataProvider.fetch_shipment_pool().GetShipment(shipmentId) == null)
-                    {
-                        response.StatusCode = (int)HttpStatusCode.NotFound;
-                        response.StatusDescription = "No data for given ID";
-                        response.Close();
-                        return;
-                    }
-                    DataProvider.fetch_shipment_pool().UpdateItemsInShipment(shipmentId, updatedItems);
-                    DataProvider.fetch_shipment_pool().Save();
-                    response.StatusCode = (int)HttpStatusCode.OK;
-                    response.Close();
-                }
-                else if (path.Length == 3 && path[2] == "commit") // Commit shipment
-                {
-                    int shipmentId = int.Parse(path[1]);
-                    var shipment = DataProvider.fetch_shipment_pool().GetShipment(shipmentId);
-                    if (shipment == null)
-                    {
-                        response.StatusCode = (int)HttpStatusCode.NotFound;
-                        response.StatusDescription = "No data found with given ID";
-                        response.Close();
-                        return;
-                    }
-                    // Update inventories based on shipment items
-                    foreach (var item in shipment.Items)
-                    {
-                        var inventories = DataProvider.fetch_inventory_pool().GetInventoriesForItem(item.Item_Id);
-                        foreach (var inventory in inventories)
-                        {
-                            if (inventory.Locations.Contains(shipment.Source_Id))
-                            {
-                                inventory.Total_On_Hand -= item.Amount;
-                            }
-                        }
-                    }
-                    shipment.Shipment_Status = "Shipped";
-                    check = DataProvider.fetch_shipment_pool().UpdateShipment(shipmentId, shipment);
-                    if (!check)
-                    {
-                        response.StatusCode = (int)HttpStatusCode.NotFound;
-                        response.StatusDescription = "ID not found or ID in Body and in Route are not matching";
-                        response.Close();
-                        return;
-                    }
-                    var notificationSystem = new NotificationSystem();
-                    notificationSystem.Push($"Shipment with id: {shipment.Id} has been processed.");
-                    DataProvider.fetch_shipment_pool().Save();
-                    DataProvider.fetch_inventory_pool().Save();
-                    response.StatusCode = (int)HttpStatusCode.OK;
-                    response.Close();
-                }
-                else
-                {
-                    response.StatusCode = (int)HttpStatusCode.NotFound;
-                    response.Close();
-                }
-                break;
-
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                break;
-        }
-
-        response.Close();
-    }
-
-
-    private void HandleDeleteVersion1(string[] path, User user, HttpListenerResponse response)
-    {
-        if (!AuthProvider.HasAccess(user, path[0], "delete"))
-        {
-            response.StatusCode = (int)HttpStatusCode.Forbidden;
-            response.Close();
-            return;
-        }
-
-        bool check;
-
-        switch (path[0])
-        {
-            case "warehouses":
-                int warehouseId = int.Parse(path[1]);
-                check = DataProvider.fetch_warehouse_pool().RemoveWarehouse(warehouseId);
-                if (check) DataProvider.fetch_warehouse_pool().Save();
-                break;
-            case "locations":
-                int locationId = int.Parse(path[1]);
-                check = DataProvider.fetch_location_pool().RemoveLocation(locationId);
-                if (check) DataProvider.fetch_location_pool().Save();
-                break;
-            case "transfers":
-                int transferId = int.Parse(path[1]);
-                check = DataProvider.fetch_transfer_pool().RemoveTransfer(transferId);
-                if (check) DataProvider.fetch_transfer_pool().Save();
-                break;
-            case "items":
-                string itemId = path[1];
-                check = DataProvider.fetch_item_pool().RemoveItem(itemId);
-                if (check) DataProvider.fetch_item_pool().Save();
-                break;
-            case "item_lines":
-                int itemLineId = int.Parse(path[1]);
-                check = DataProvider.fetch_itemline_pool().RemoveItemline(itemLineId);
-                if (check) DataProvider.fetch_itemline_pool().Save();
-                break;
-            case "item_groups":
-                int itemGroupId = int.Parse(path[1]);
-                check = DataProvider.fetch_itemgroup_pool().RemoveItemGroup(itemGroupId);
-                if (check) DataProvider.fetch_itemgroup_pool().Save();
-                break;
-            case "item_types":
-                int itemTypeId = int.Parse(path[1]);
-                check = DataProvider.fetch_itemtype_pool().RemoveItemtype(itemTypeId);
-                if (check) DataProvider.fetch_itemtype_pool().Save();
-                break;
-            case "inventories":
-                int inventoryId = int.Parse(path[1]);
-                check = DataProvider.fetch_inventory_pool().RemoveInventory(inventoryId);
-                if (check) DataProvider.fetch_inventory_pool().Save();
-                break;
-            case "suppliers":
-                int supplierId = int.Parse(path[1]);
-                check = DataProvider.fetch_supplier_pool().RemoveSupplier(supplierId);
-                if (check) DataProvider.fetch_supplier_pool().Save();
-                break;
-            case "orders":
-                int orderId = int.Parse(path[1]);
-                check = DataProvider.fetch_order_pool().RemoveOrder(orderId);
-                if (check) DataProvider.fetch_order_pool().Save();
-                break;
-            case "clients":
-                int clientId = int.Parse(path[1]);
-                check = DataProvider.fetch_client_pool().RemoveClient(clientId);
-                if (check) DataProvider.fetch_client_pool().Save();
-                break;
-            case "shipments":
-                int shipmentId = int.Parse(path[1]);
-                check = DataProvider.fetch_shipment_pool().RemoveShipment(shipmentId);
-                if (check) DataProvider.fetch_shipment_pool().Save();
-                break;
-            default:
-                response.StatusCode = (int)HttpStatusCode.NotFound;
-                response.Close();
-                return;
-        }
-
-        if (!check)
-        {
-            response.StatusCode = (int)HttpStatusCode.NotFound;
-            response.StatusDescription = "ID not found or other data is dependent on this data";
-            response.Close();
-            return;
-        }
-
-        response.StatusCode = (int)HttpStatusCode.OK;
-        response.Close();
-    }
-
-
-    private void SendResponse(HttpListenerResponse response, object data)
-    {
-        response.StatusCode = (int)HttpStatusCode.OK;
-        if (data == null) response.StatusCode = (int)HttpStatusCode.NotFound;
-        response.ContentType = "application/json";
-        using (var writer = new StreamWriter(response.OutputStream))
-        {
-            string jsonResponse = System.Text.Json.JsonSerializer.Serialize(data);
-            writer.Write(jsonResponse);
-        }
-        response.Close();
-    }
-}
diff --git a/C#api/Controllers/BaseApiController.cs b/C#api/Controllers/BaseApiController.cs
new file mode 100644
index 0000000..39bfe74
--- /dev/null
+++ b/C#api/Controllers/BaseApiController.cs
@@ -0,0 +1,27 @@
+using Microsoft.AspNetCore.Mvc;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public abstract class BaseApiController : ControllerBase
+{
+    protected readonly NotificationSystem _notificationSystem;
+
+    public BaseApiController(
+        NotificationSystem notificationSystem)
+    {
+        _notificationSystem = notificationSystem;
+    }
+
+    protected IActionResult CheckAuthorization(string apiKey, string resource, string operation)
+    {
+        var user = AuthProvider.GetUser(apiKey);
+        if (user == null)
+            return Unauthorized();
+
+        if (!AuthProvider.HasAccess(user, resource, operation))
+            return Forbid();
+
+        return null;
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/ClientsController.cs b/C#api/Controllers/ClientsController.cs
new file mode 100644
index 0000000..870aae2
--- /dev/null
+++ b/C#api/Controllers/ClientsController.cs
@@ -0,0 +1,89 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class ClientsController : BaseApiController
+{
+    public ClientsController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetClients()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "clients", "get");
+        if (auth != null) return auth;
+
+        var clients = DataProvider.fetch_client_pool().GetClients();
+        return Ok(clients);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetClient(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "clients", "get");
+        if (auth != null) return auth;
+
+        var client = DataProvider.fetch_client_pool().GetClient(id);
+        if (client == null) return NotFound();
+
+        return Ok(client);
+    }
+
+    [HttpGet("{id}/orders")]
+    public IActionResult GetClientOrders(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "clients", "get");
+        if (auth != null) return auth;
+
+        var orders = DataProvider.fetch_order_pool().GetOrdersForClient(id);
+        return Ok(orders);
+    }
+
+    [HttpPost]
+    public IActionResult CreateClient([FromBody] Client client)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "clients", "post");
+        if (auth != null) return auth;
+
+        if (client.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_client_pool().AddClient(client);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_client_pool().Save();
+        return CreatedAtAction(nameof(GetClient), new { id = client.Id }, client);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateClient(int id, [FromBody] Client client)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "clients", "put");
+        if (auth != null) return auth;
+
+        if (client.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_client_pool().UpdateClient(id, client);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_client_pool().Save();
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteClient(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "clients", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_client_pool().RemoveClient(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_client_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/InventoriesController.cs b/C#api/Controllers/InventoriesController.cs
new file mode 100644
index 0000000..2ea49a9
--- /dev/null
+++ b/C#api/Controllers/InventoriesController.cs
@@ -0,0 +1,79 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class InventoriesController : BaseApiController
+{
+    public InventoriesController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetInventories()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "inventories", "get");
+        if (auth != null) return auth;
+
+        var inventories = DataProvider.fetch_inventory_pool().GetInventories();
+        return Ok(inventories);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetInventory(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "inventories", "get");
+        if (auth != null) return auth;
+
+        var inventory = DataProvider.fetch_inventory_pool().GetInventory(id);
+        if (inventory == null) return NotFound();
+
+        return Ok(inventory);
+    }
+
+    [HttpPost]
+    public IActionResult CreateInventory([FromBody] Inventory inventory)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "inventories", "post");
+        if (auth != null) return auth;
+
+        if (inventory.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_inventory_pool().AddInventory(inventory);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_inventory_pool().Save();
+        return CreatedAtAction(nameof(GetInventory), new { id = inventory.Id }, inventory);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateInventory(int id, [FromBody] Inventory inventory)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "inventories", "put");
+        if (auth != null) return auth;
+
+        if (inventory.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_inventory_pool().UpdateInventory(id, inventory);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_inventory_pool().Save();
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteInventory(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "inventories", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_inventory_pool().RemoveInventory(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_inventory_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/Item_GroupsController.cs b/C#api/Controllers/Item_GroupsController.cs
new file mode 100644
index 0000000..e314c6e
--- /dev/null
+++ b/C#api/Controllers/Item_GroupsController.cs
@@ -0,0 +1,89 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class Item_GroupsController : BaseApiController
+{
+    public Item_GroupsController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetItemGroups()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_groups", "get");
+        if (auth != null) return auth;
+
+        var itemGroups = DataProvider.fetch_itemgroup_pool().GetItemGroups();
+        return Ok(itemGroups);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetItemGroup(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_groups", "get");
+        if (auth != null) return auth;
+
+        var itemGroup = DataProvider.fetch_itemgroup_pool().GetItemGroup(id);
+        if (itemGroup == null) return NotFound();
+
+        return Ok(itemGroup);
+    }
+
+    [HttpGet("{id}/items")]
+    public IActionResult GetItemGroupItems(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_groups", "get");
+        if (auth != null) return auth;
+
+        var items = DataProvider.fetch_item_pool().GetItemsForItemGroup(id);
+        return Ok(items);
+    }
+
+    [HttpPost]
+    public IActionResult CreateItemGroup([FromBody] ItemGroup itemGroup)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_groups", "post");
+        if (auth != null) return auth;
+
+        if (itemGroup.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_itemgroup_pool().AddItemGroup(itemGroup);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_itemgroup_pool().Save();
+        return CreatedAtAction(nameof(GetItemGroup), new { id = itemGroup.Id }, itemGroup);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateItemGroup(int id, [FromBody] ItemGroup itemGroup)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_groups", "put");
+        if (auth != null) return auth;
+
+        if (itemGroup.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_itemgroup_pool().UpdateItemGroup(id, itemGroup);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_itemgroup_pool().Save();
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteItemGroup(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_groups", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_itemgroup_pool().RemoveItemGroup(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_itemgroup_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/Item_LinesController.cs b/C#api/Controllers/Item_LinesController.cs
new file mode 100644
index 0000000..238d807
--- /dev/null
+++ b/C#api/Controllers/Item_LinesController.cs
@@ -0,0 +1,89 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class Item_LinesController : BaseApiController
+{
+    public Item_LinesController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetItemLines()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_lines", "get");
+        if (auth != null) return auth;
+
+        var itemLines = DataProvider.fetch_itemline_pool().GetItemLines();
+        return Ok(itemLines);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetItemLine(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_lines", "get");
+        if (auth != null) return auth;
+
+        var itemLine = DataProvider.fetch_itemline_pool().GetItemLine(id);
+        if (itemLine == null) return NotFound();
+
+        return Ok(itemLine);
+    }
+
+    [HttpGet("{id}/items")]
+    public IActionResult GetItemLineItems(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_lines", "get");
+        if (auth != null) return auth;
+
+        var items = DataProvider.fetch_item_pool().GetItemsForItemLine(id);
+        return Ok(items);
+    }
+
+    [HttpPost]
+    public IActionResult CreateItemLine([FromBody] ItemLine itemLine)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_lines", "post");
+        if (auth != null) return auth;
+
+        if (itemLine.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_itemline_pool().AddItemline(itemLine);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_itemline_pool().Save();
+        return CreatedAtAction(nameof(GetItemLine), new { id = itemLine.Id }, itemLine);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateItemLine(int id, [FromBody] ItemLine itemLine)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_lines", "put");
+        if (auth != null) return auth;
+
+        if (itemLine.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_itemline_pool().UpdateItemline(id, itemLine);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_itemline_pool().Save();
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteItemLine(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_lines", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_itemline_pool().RemoveItemline(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_itemline_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/Item_TypesController.cs b/C#api/Controllers/Item_TypesController.cs
new file mode 100644
index 0000000..88f75c7
--- /dev/null
+++ b/C#api/Controllers/Item_TypesController.cs
@@ -0,0 +1,89 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class Item_TypesController : BaseApiController
+{
+    public Item_TypesController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetItemTypes()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_types", "get");
+        if (auth != null) return auth;
+
+        var itemTypes = DataProvider.fetch_itemtype_pool().GetItemTypes();
+        return Ok(itemTypes);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetItemType(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_types", "get");
+        if (auth != null) return auth;
+
+        var itemType = DataProvider.fetch_itemtype_pool().GetItemType(id);
+        if (itemType == null) return NotFound();
+
+        return Ok(itemType);
+    }
+
+    [HttpGet("{id}/items")]
+    public IActionResult GetItemTypeItems(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_types", "get");
+        if (auth != null) return auth;
+
+        var items = DataProvider.fetch_item_pool().GetItemsForItemType(id);
+        return Ok(items);
+    }
+
+    [HttpPost]
+    public IActionResult CreateItemType([FromBody] ItemType itemType)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_types", "post");
+        if (auth != null) return auth;
+
+        if (itemType.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_itemtype_pool().AddItemtype(itemType);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_itemtype_pool().Save();
+        return CreatedAtAction(nameof(GetItemType), new { id = itemType.Id }, itemType);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateItemType(int id, [FromBody] ItemType itemType)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_types", "put");
+        if (auth != null) return auth;
+
+        if (itemType.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_itemtype_pool().UpdateItemtype(id, itemType);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_itemtype_pool().Save();
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteItemType(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "item_types", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_itemtype_pool().RemoveItemtype(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_itemtype_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/ItemsController.cs b/C#api/Controllers/ItemsController.cs
new file mode 100644
index 0000000..8362f24
--- /dev/null
+++ b/C#api/Controllers/ItemsController.cs
@@ -0,0 +1,99 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class ItemsController : BaseApiController
+{
+    public ItemsController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetItems()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "items", "get");
+        if (auth != null) return auth;
+
+        var items = DataProvider.fetch_item_pool().GetItems();
+        return Ok(items);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetItem(string id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "items", "get");
+        if (auth != null) return auth;
+
+        var item = DataProvider.fetch_item_pool().GetItem(id);
+        if (item == null) return NotFound();
+
+        return Ok(item);
+    }
+
+    [HttpGet("{id}/inventory")]
+    public IActionResult GetItemInventories(string id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "items", "get");
+        if (auth != null) return auth;
+
+        var inventories = DataProvider.fetch_inventory_pool().GetInventoriesForItem(id);
+        return Ok(inventories);
+    }
+
+    [HttpGet("{id}/inventory/totals")]
+    public IActionResult GetItemInventoryTotals(string id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "items", "get");
+        if (auth != null) return auth;
+
+        var totals = DataProvider.fetch_inventory_pool().GetInventoryTotalsForItem(id);
+        return Ok(totals);
+    }
+
+    [HttpPost]
+    public IActionResult CreateItem([FromBody] Item item)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "items", "post");
+        if (auth != null) return auth;
+
+        if (item.Uid == null) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_item_pool().AddItem(item);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_item_pool().Save();
+        return CreatedAtAction(nameof(GetItem), new { id = item.Uid }, item);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateItem(string id, [FromBody] Item item)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "items", "put");
+        if (auth != null) return auth;
+
+        if (item.Uid == null) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_item_pool().UpdateItem(id, item);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_item_pool().Save();
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteItem(string id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "items", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_item_pool().RemoveItem(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_item_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/LocationsController.cs b/C#api/Controllers/LocationsController.cs
new file mode 100644
index 0000000..cbf518d
--- /dev/null
+++ b/C#api/Controllers/LocationsController.cs
@@ -0,0 +1,89 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class LocationsController : BaseApiController
+{
+    public LocationsController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetLocations()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "locations", "get");
+        if (auth != null) return auth;
+
+        var locations = DataProvider.fetch_location_pool().GetLocations();
+        return Ok(locations);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetLocation(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "locations", "get");
+        if (auth != null) return auth;
+
+        var location = DataProvider.fetch_location_pool().GetLocation(id);
+        if (location == null) return NotFound();
+
+        return Ok(location);
+    }
+
+    [HttpGet("{id}/inventory")]
+    public IActionResult GetLocationInventory(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "locations", "get");
+        if (auth != null) return auth;
+
+        var inventory = DataProvider.fetch_location_pool().GetLocationsInWarehouse(id);
+        return Ok(inventory);
+    }
+
+    [HttpPost]
+    public IActionResult CreateLocation([FromBody] Location location)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "locations", "post");
+        if (auth != null) return auth;
+
+        if (location.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_location_pool().AddLocation(location);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_location_pool().Save();
+        return CreatedAtAction(nameof(GetLocation), new { id = location.Id }, location);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateLocation(int id, [FromBody] Location location)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "locations", "put");
+        if (auth != null) return auth;
+
+        if (location.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_location_pool().UpdateLocation(id, location);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_location_pool().Save();
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteLocation(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "locations", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_location_pool().RemoveLocation(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_location_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/OrdersController.cs b/C#api/Controllers/OrdersController.cs
new file mode 100644
index 0000000..116bfa1
--- /dev/null
+++ b/C#api/Controllers/OrdersController.cs
@@ -0,0 +1,136 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class OrdersController : BaseApiController
+{
+    public OrdersController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetOrders()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "orders", "get");
+        if (auth != null) return auth;
+
+        var orders = DataProvider.fetch_order_pool().GetOrders();
+        return Ok(orders);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetOrder(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "orders", "get");
+        if (auth != null) return auth;
+
+        var order = DataProvider.fetch_order_pool().GetOrder(id);
+        if (order == null) return NotFound();
+
+        return Ok(order);
+    }
+
+    [HttpGet("{id}/items")]
+    public IActionResult GetOrderItems(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "orders", "get");
+        if (auth != null) return auth;
+
+        var items = DataProvider.fetch_order_pool().GetItemsInOrder(id);
+        return Ok(items);
+    }
+
+    [HttpPost]
+    public IActionResult CreateOrder([FromBody] Order order)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "orders", "post");
+        if (auth != null) return auth;
+
+        if (order.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_order_pool().AddOrder(order);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_order_pool().Save();
+        return CreatedAtAction(nameof(GetOrder), new { id = order.Id }, order);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateOrder(int id, [FromBody] Order order)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "orders", "put");
+        if (auth != null) return auth;
+
+        if (order.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_order_pool().UpdateOrder(id, order);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_order_pool().Save();
+        return Ok();
+    }
+
+    [HttpPut("{id}/items")]
+    public IActionResult UpdateOrderItems(int id, [FromBody] List<Item> items)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "orders", "put");
+        if (auth != null) return auth;
+
+        if (items.Any(x => x.Uid == null)) return BadRequest("ID not given in body");
+
+        if (DataProvider.fetch_order_pool().GetOrder(id) == null)
+            return NotFound("No data for given ID");
+
+        DataProvider.fetch_order_pool().UpdateItemsInOrder(id, items);
+        DataProvider.fetch_order_pool().Save();
+        return Ok();
+    }
+
+    [HttpPut("{id}/commit")]
+    public IActionResult CommitOrder(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "orders", "put");
+        if (auth != null) return auth;
+
+        var order = DataProvider.fetch_order_pool().GetOrder(id);
+        if (order == null) return NotFound("No data found with given ID");
+
+        foreach (var item in order.Items)
+        {
+            var inventories = DataProvider.fetch_inventory_pool().GetInventoriesForItem(item.Item_Id);
+            foreach (var inventory in inventories)
+            {
+                if (inventory.Locations.Contains(order.Source_Id))
+                {
+                    inventory.Total_On_Hand -= item.Amount;
+                }
+            }
+        }
+
+        order.Order_Status = "Processed";
+        var success = DataProvider.fetch_order_pool().UpdateOrder(id, order);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        _notificationSystem.Push($"Order with id: {order.Id} has been processed.");
+        DataProvider.fetch_order_pool().Save();
+        DataProvider.fetch_inventory_pool().Save();
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteOrder(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "orders", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_order_pool().RemoveOrder(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_order_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/ShipmentsController.cs b/C#api/Controllers/ShipmentsController.cs
new file mode 100644
index 0000000..9af786b
--- /dev/null
+++ b/C#api/Controllers/ShipmentsController.cs
@@ -0,0 +1,162 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class ShipmentsController : BaseApiController
+{
+    public ShipmentsController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetShipments()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "shipments", "get");
+        if (auth != null) return auth;
+
+        var shipments = DataProvider.fetch_shipment_pool().GetShipments();
+        return Ok(shipments);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetShipment(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "shipments", "get");
+        if (auth != null) return auth;
+
+        var shipment = DataProvider.fetch_shipment_pool().GetShipment(id);
+        if (shipment == null) return NotFound();
+
+        return Ok(shipment);
+    }
+
+    [HttpGet("{id}/orders")]
+    public IActionResult GetShipmentOrders(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "shipments", "get");
+        if (auth != null) return auth;
+
+        var orders = DataProvider.fetch_order_pool().GetOrdersInShipment(id);
+        return Ok(orders);
+    }
+
+    [HttpGet("{id}/items")]
+    public IActionResult GetShipmentItems(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "shipments", "get");
+        if (auth != null) return auth;
+
+        var items = DataProvider.fetch_shipment_pool().GetItemsInShipment(id);
+        return Ok(items);
+    }
+
+    [HttpPost]
+    public IActionResult CreateShipment([FromBody] Shipment shipment)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "shipments", "post");
+        if (auth != null) return auth;
+
+        if (shipment.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_shipment_pool().AddShipment(shipment);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_shipment_pool().Save();
+        return CreatedAtAction(nameof(GetShipment), new { id = shipment.Id }, shipment);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateShipment(int id, [FromBody] Shipment shipment)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "shipments", "put");
+        if (auth != null) return auth;
+
+        if (shipment.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_shipment_pool().UpdateShipment(id, shipment);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_shipment_pool().Save();
+        return Ok();
+    }
+
+    [HttpPut("{id}/orders")]
+    public IActionResult UpdateShipmentOrders(int id, [FromBody] List<Order> orders)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "shipments", "put");
+        if (auth != null) return auth;
+
+        if (orders.Any(x => x.Id == -10)) return BadRequest("ID not given in body");
+
+        if (DataProvider.fetch_shipment_pool().GetShipment(id) == null)
+            return NotFound("No data for given ID");
+
+        DataProvider.fetch_order_pool().UpdateOrdersInShipment(id, orders);
+        DataProvider.fetch_order_pool().Save();
+        return Ok();
+    }
+
+    [HttpPut("{id}/items")]
+    public IActionResult UpdateShipmentItems(int id, [FromBody] List<Item> items)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "shipments", "put");
+        if (auth != null) return auth;
+
+        if (items.Any(x => x.Uid == null)) return BadRequest("ID not given in body");
+
+        if (DataProvider.fetch_shipment_pool().GetShipment(id) == null)
+            return NotFound("No data for given ID");
+
+        DataProvider.fetch_shipment_pool().UpdateItemsInShipment(id, items);
+        DataProvider.fetch_shipment_pool().Save();
+        return Ok();
+    }
+
+    [HttpPut("{id}/commit")]
+    public IActionResult CommitShipment(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "shipments", "put");
+        if (auth != null) return auth;
+
+        var shipment = DataProvider.fetch_shipment_pool().GetShipment(id);
+        if (shipment == null) return NotFound("No data found with given ID");
+
+        foreach (var item in shipment.Items)
+        {
+            var inventories = DataProvider.fetch_inventory_pool().GetInventoriesForItem(item.Item_Id);
+            foreach (var inventory in inventories)
+            {
+                if (inventory.Locations.Contains(shipment.Source_Id))
+                {
+                    inventory.Total_On_Hand -= item.Amount;
+                }
+            }
+        }
+
+        shipment.Shipment_Status = "Shipped";
+        var success = DataProvider.fetch_shipment_pool().UpdateShipment(id, shipment);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        _notificationSystem.Push($"Shipment with id: {shipment.Id} has been processed.");
+        DataProvider.fetch_shipment_pool().Save();
+        DataProvider.fetch_inventory_pool().Save();
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteShipment(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "shipments", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_shipment_pool().RemoveShipment(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_shipment_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/SuppliersController.cs b/C#api/Controllers/SuppliersController.cs
new file mode 100644
index 0000000..f4b85ca
--- /dev/null
+++ b/C#api/Controllers/SuppliersController.cs
@@ -0,0 +1,89 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class SuppliersController : BaseApiController
+{
+    public SuppliersController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetSuppliers()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "suppliers", "get");
+        if (auth != null) return auth;
+
+        var suppliers = DataProvider.fetch_supplier_pool().GetSuppliers();
+        return Ok(suppliers);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetSupplier(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "suppliers", "get");
+        if (auth != null) return auth;
+
+        var supplier = DataProvider.fetch_supplier_pool().GetSupplier(id);
+        if (supplier == null) return NotFound();
+
+        return Ok(supplier);
+    }
+
+    [HttpGet("{id}/items")]
+    public IActionResult GetSupplierItems(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "suppliers", "get");
+        if (auth != null) return auth;
+
+        var items = DataProvider.fetch_item_pool().GetItemsForSupplier(id);
+        return Ok(items);
+    }
+
+    [HttpPost]
+    public IActionResult CreateSupplier([FromBody] Supplier supplier)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "suppliers", "post");
+        if (auth != null) return auth;
+
+        if (supplier.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_supplier_pool().AddSupplier(supplier);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_supplier_pool().Save();
+        return CreatedAtAction(nameof(GetSupplier), new { id = supplier.Id }, supplier);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateSupplier(int id, [FromBody] Supplier supplier)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "suppliers", "put");
+        if (auth != null) return auth;
+
+        if (supplier.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_supplier_pool().UpdateSupplier(id, supplier);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_supplier_pool().Save();
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteSupplier(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "suppliers", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_supplier_pool().RemoveSupplier(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_supplier_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/TransfersController.cs b/C#api/Controllers/TransfersController.cs
new file mode 100644
index 0000000..764ea0e
--- /dev/null
+++ b/C#api/Controllers/TransfersController.cs
@@ -0,0 +1,147 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class TransfersController : BaseApiController
+{
+    public TransfersController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetTransfers()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "transfers", "get");
+        if (auth != null) return auth;
+
+        var transfers = DataProvider.fetch_transfer_pool().GetTransfers();
+        return Ok(transfers);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetTransfer(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "transfers", "get");
+        if (auth != null) return auth;
+
+        var transfer = DataProvider.fetch_transfer_pool().GetTransfer(id);
+        if (transfer == null) return NotFound();
+
+        return Ok(transfer);
+    }
+
+    [HttpGet("{id}/items")]
+    public IActionResult GetTransferItems(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "transfers", "get");
+        if (auth != null) return auth;
+
+        var items = DataProvider.fetch_transfer_pool().GetItemsInTransfer(id);
+        return Ok(items);
+    }
+
+    [HttpPost]
+    public IActionResult CreateTransfer([FromBody] Transfer transfer)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "transfers", "post");
+        if (auth != null) return auth;
+
+        if (transfer.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_transfer_pool().AddTransfer(transfer);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_transfer_pool().Save();
+        return CreatedAtAction(nameof(GetTransfer), new { id = transfer.Id }, transfer);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateTransfer(int id, [FromBody] Transfer transfer)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "transfers", "put");
+        if (auth != null) return auth;
+
+        if (transfer.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_transfer_pool().UpdateTransfer(id, transfer);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_transfer_pool().Save();
+        return Ok();
+    }
+
+    // [HttpPut("{id}/items")]
+    // public IActionResult UpdateTransferItems(int id, [FromBody] List<Item> items)
+    // {
+    //     var auth = CheckAuthorization(Request.Headers["API_KEY"], "transfers", "put");
+    //     if (auth != null) return auth;
+
+    //     if (items.Any(x => x.Uid == null)) return BadRequest("ID not given in body");
+
+    //     if (DataProvider.fetch_transfer_pool().GetTransfer(id) == null)
+    //         return NotFound("No data for given ID");
+
+    //     DataProvider.fetch_item_pool().UpdateItemsInTransfer(id, items);
+    //     DataProvider.fetch_transfer_pool().Save();
+    //     return Ok();
+    // }
+
+    [HttpPut("{id}/commit")]
+    public IActionResult CommitTransfer(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "transfers", "put");
+        if (auth != null) return auth;
+
+        var transfer = DataProvider.fetch_transfer_pool().GetTransfer(id);
+        if (transfer == null) return NotFound("Transfer not found");
+
+        if (transfer.Id == -10) return BadRequest("Invalid transfer ID");
+
+        // Update inventories based on transfer items
+        foreach (var item in transfer.Items)
+        {
+            var inventories = DataProvider.fetch_inventory_pool().GetInventoriesForItem(item.Item_Id);
+            foreach (var inventory in inventories)
+            {
+                if (transfer.Transfer_From is null) break;
+                if (inventory.Locations.Contains((int)transfer.Transfer_From))
+                {
+                    inventory.Total_On_Hand -= item.Amount;
+                }
+                else if (inventory.Locations.Contains((int)transfer.Transfer_To))
+                {
+                    inventory.Total_On_Hand += item.Amount;
+                }
+                DataProvider.fetch_inventory_pool().UpdateInventory(inventory.Id, inventory);
+            }
+        }
+
+        transfer.Transfer_Status = "Processed";
+        var success = DataProvider.fetch_transfer_pool().UpdateTransfer(id, transfer);
+        if (!success) return NotFound("Failed to update transfer status");
+
+        _notificationSystem.Push($"Processed batch transfer with id: {transfer.Id}");
+        
+        DataProvider.fetch_transfer_pool().Save();
+        DataProvider.fetch_inventory_pool().Save();
+        
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteTransfer(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "transfers", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_transfer_pool().RemoveTransfer(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_transfer_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Controllers/WarehousesController.cs b/C#api/Controllers/WarehousesController.cs
new file mode 100644
index 0000000..b391378
--- /dev/null
+++ b/C#api/Controllers/WarehousesController.cs
@@ -0,0 +1,99 @@
+using Microsoft.AspNetCore.Mvc;
+using Models;
+using Providers;
+
+[ApiController]
+[Route("api/v1/[controller]")]
+public class WarehousesController : BaseApiController
+{
+    public WarehousesController(
+        NotificationSystem notificationSystem)
+        : base(notificationSystem)
+    {
+    }
+
+    [HttpGet]
+    public IActionResult GetWarehouses()
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "warehouses", "get");
+        if (auth != null) return auth;
+
+        var warehouses = DataProvider.fetch_warehouse_pool().GetWarehouses();
+        return Ok(warehouses);
+    }
+
+    [HttpGet("{id}")]
+    public IActionResult GetWarehouse(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "warehouses", "get");
+        if (auth != null) return auth;
+
+        var warehouse = DataProvider.fetch_warehouse_pool().GetWarehouse(id);
+        if (warehouse == null) return NotFound();
+
+        return Ok(warehouse);
+    }
+
+    [HttpGet("{id}/locations")]
+    public IActionResult GetWarehouseLocations(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "warehouses", "get");
+        if (auth != null) return auth;
+
+        var locations = DataProvider.fetch_location_pool().GetLocationsInWarehouse(id);
+        return Ok(locations);
+    }
+
+    // [HttpGet("{id}/inventory")]
+    // public IActionResult GetWarehouseInventory(int id)
+    // {
+    //     var auth = CheckAuthorization(Request.Headers["API_KEY"], "warehouses", "get");
+    //     if (auth != null) return auth;
+
+    //     var inventory = DataProvider.fetch_inventory_pool().GetInventoryForWarehouse(id);
+    //     return Ok(inventory);
+    // }
+
+    [HttpPost]
+    public IActionResult CreateWarehouse([FromBody] Warehouse warehouse)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "warehouses", "post");
+        if (auth != null) return auth;
+
+        if (warehouse.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_warehouse_pool().AddWarehouse(warehouse);
+        if (!success) return NotFound("ID already exists in data");
+
+        DataProvider.fetch_warehouse_pool().Save();
+        return CreatedAtAction(nameof(GetWarehouse), new { id = warehouse.Id }, warehouse);
+    }
+
+    [HttpPut("{id}")]
+    public IActionResult UpdateWarehouse(int id, [FromBody] Warehouse warehouse)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "warehouses", "put");
+        if (auth != null) return auth;
+
+        if (warehouse.Id == -10) return BadRequest("ID not given in body");
+
+        var success = DataProvider.fetch_warehouse_pool().UpdateWarehouse(id, warehouse);
+        if (!success) return NotFound("ID not found or ID in Body and Route are not matching");
+
+        DataProvider.fetch_warehouse_pool().Save();
+        return Ok();
+    }
+
+    [HttpDelete("{id}")]
+    public IActionResult DeleteWarehouse(int id)
+    {
+        var auth = CheckAuthorization(Request.Headers["API_KEY"], "warehouses", "delete");
+        if (auth != null) return auth;
+
+        var success = DataProvider.fetch_warehouse_pool().RemoveWarehouse(id);
+        if (!success) return NotFound("ID not found or other data is dependent on this data");
+
+        DataProvider.fetch_warehouse_pool().Save();
+        return Ok();
+    }
+}
\ No newline at end of file
diff --git a/C#api/Program.cs b/C#api/Program.cs
index 38b22d3..cce60c4 100644
--- a/C#api/Program.cs
+++ b/C#api/Program.cs
@@ -1,56 +1,42 @@
-using System;
-using System.Net;
-using System.Threading.Tasks;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Providers;
 
-public class Program
-{
-    private const int PORT = 3000;
+var builder = WebApplication.CreateBuilder(args);
 
-    public static void Main()
+// Add services to the container.
+builder.Services.AddControllers()
+    .AddJsonOptions(options =>
     {
-        var httpListener = new HttpListener();
-        httpListener.Prefixes.Add($"http://127.0.0.1:{PORT}/");
-
-        AuthProvider.Init(); // Initialize authentication provider
-        DataProvider.Init(); // Initialize data provider
-        NotificationSystem n = new NotificationSystem();
-        NotificationSystem.Start(); // Start notification processor
-
-        httpListener.Start();
-        Console.WriteLine($"Serving on port {PORT}...");
-
-        Task.Run(async () =>
-        {
-            while (true)
-            {
-                var context = await httpListener.GetContextAsync();
-                var handler = new ApiRequestHandler();
-
-                // Determine the HTTP method and call the appropriate handler
-                switch (context.Request.HttpMethod)
-                {
-                    case "GET":
-                        handler.HandleGet(context.Request, context.Response);
-                        break;
-                    case "POST":
-                        handler.HandlePost(context.Request, context.Response);
-                        break;
-                    case "PUT":
-                        handler.HandlePut(context.Request, context.Response);
-                        break;
-                    case "DELETE":
-                        handler.HandleDelete(context.Request, context.Response);
-                        break;
-                    default:
-                        context.Response.StatusCode = (int)HttpStatusCode.MethodNotAllowed;
-                        context.Response.Close();
-                        break;
-                }
-            }
-        });
-
-        // Prevent the main thread from exiting
-        Console.ReadLine();
-        httpListener.Stop();
-    }
+        options.JsonSerializerOptions.PropertyNamingPolicy = null;  // Disable camelCase
+    });
+builder.Services.AddEndpointsApiExplorer();
+builder.Services.AddSwaggerGen();
+
+// Register your services
+builder.Services.AddSingleton<AuthProvider>();
+builder.Services.AddSingleton<DataProvider>();
+builder.Services.AddSingleton<NotificationSystem>();
+
+var app = builder.Build();
+
+// Initialize your providers
+AuthProvider.Init();
+DataProvider.Init();
+// NotificationSystem.Start();
+
+// Configure the HTTP request pipeline.
+if (app.Environment.IsDevelopment())
+{
+    app.UseSwagger();
+    app.UseSwaggerUI();
 }
+
+app.UseHttpsRedirection();
+app.UseAuthorization();
+app.MapControllers();
+app.Urls.Add("http://localhost:3000/");
+
+app.Run();
+Console.WriteLine("Hello");
\ No newline at end of file
diff --git a/C#api/Tests/test_orders.py b/C#api/Tests/test_orders.py
index e8ab4df..bfff3ac 100644
--- a/C#api/Tests/test_orders.py
+++ b/C#api/Tests/test_orders.py
@@ -91,17 +91,25 @@ def test_6create_duplicate_order(self):
     # PUT tests
     def test_7update_existing_order(self):
         updated_order = {
-            "Id": self.new_order['Id'],  # Keep the same Id
-            "Reference": "ORD124",  # Changed Reference
-            "Order_Status": "Completed",  # Changed Status
-            "Total_Amount": 1100.00,  # Changed Amount
-            "Total_Tax": 120.00,  # Changed Tax
+            "Id": 0,
+            "Source_Id": 1, 
+            "Order_Date": "2024-11-14T16:10:14.227318",
+            "Request_Date": "2024-11-14T16:10:14.227318",
+            "Reference": "ORD123",
+            "Reference_Extra": "Extra details here",
+            "Order_Status": "Completed",
+            "Notes": "Order notes",
+            "Shipping_Notes": "Shipping instructions",
+            "Picking_Notes": "Picking instructions",
+            "Warehouse_Id": 1,  
+            "Total_Amount": 1000.00,
+            "Total_Discount": 50.00,
+            "Total_Tax": 100.00,
+            "Total_Surcharge": 20.00,
             "Items": [
-                {"Item_Id": "ITEM789", "Amount": 200},
-                {"Item_Id": "ITEM101", "Amount": 150}
-            ],
-            "Created_At": self.new_order['Created_At'],  # Keep the same creation time
-            "Updated_At": "2024-11-14T16:10:14.227318",  # New update time
+                {"Item_Id": "ITEM123", "Amount": 100},
+                {"Item_Id": "ITEM456", "Amount": 50}
+            ]
         }
 
         response = self.client.put(f"orders/{self.new_order['Id']}", content=json.dumps(updated_order), headers={"Content-Type": "application/json"})
diff --git a/C#api/models/clients.cs b/C#api/models/clients.cs
index 64546e3..487ba71 100644
--- a/C#api/models/clients.cs
+++ b/C#api/models/clients.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq;
 using Newtonsoft.Json;
+using Providers;
 namespace Models;
 
 public class Client
@@ -17,8 +18,8 @@ public class Client
     public string Contact_name { get; set; }
     public string Contact_phone { get; set; }
     public string Contact_email { get; set; }
-    public string Created_at { get; set; }
-    public string Updated_at { get; set; }
+    public string? Created_at { get; set; }
+    public string? Updated_at { get; set; }
 }
 
 public class Clients : Base
diff --git a/C#api/models/inventories.cs b/C#api/models/inventories.cs
index d7d09cc..539d7c2 100644
--- a/C#api/models/inventories.cs
+++ b/C#api/models/inventories.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Text.Json;
 using Newtonsoft.Json;
+using Providers;
 namespace Models;
 
 public class Inventory
@@ -17,8 +18,8 @@ public class Inventory
     public int Total_Ordered { get; set; }
     public int Total_Allocated { get; set; }
     public int Total_Available { get; set; }
-    public string Created_At { get; set; }
-    public string Updated_At { get; set; }
+    public string? Created_At { get; set; }
+    public string? Updated_At { get; set; }
 }
 
 public class Inventories : Base
diff --git a/C#api/models/item_groups.cs b/C#api/models/item_groups.cs
index 8e01fb0..d5de309 100644
--- a/C#api/models/item_groups.cs
+++ b/C#api/models/item_groups.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Text.Json;
 using Newtonsoft.Json;
+using Providers;
 namespace Models;
 
 public class ItemGroup
@@ -10,8 +11,8 @@ public class ItemGroup
     public int Id { get; set; } = -10;
     public string Name { get; set; }
     public string Description { get; set; }
-    public string Created_At { get; set; }
-    public string Updated_At { get; set; }
+    public string? Created_At { get; set; }
+    public string? Updated_At { get; set; }
 }
 
 public class ItemGroups : Base
diff --git a/C#api/models/item_lines.cs b/C#api/models/item_lines.cs
index f3d8925..48fdae2 100644
--- a/C#api/models/item_lines.cs
+++ b/C#api/models/item_lines.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Text.Json;
 using Newtonsoft.Json;
+using Providers;
 namespace Models;
 
 
@@ -11,8 +12,8 @@ public class ItemLine
     public int Id { get; set; } = -10;
     public string Name { get; set; }
     public string Description { get; set; }
-    public string Created_At { get; set; }
-    public string Updated_At { get; set; }
+    public string? Created_At { get; set; }
+    public string? Updated_At { get; set; }
 }
 
 public class ItemLines : Base
diff --git a/C#api/models/item_types.cs b/C#api/models/item_types.cs
index daa985c..df04564 100644
--- a/C#api/models/item_types.cs
+++ b/C#api/models/item_types.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Text.Json;
 using Newtonsoft.Json;
+using Providers;
 namespace Models;
 
 public class ItemType
@@ -10,8 +11,8 @@ public class ItemType
     public int Id { get; set; } = -10;
     public string Name { get; set; }
     public string Description { get; set; }
-    public string Created_At { get; set; }
-    public string Updated_At { get; set; }
+    public string? Created_At { get; set; }
+    public string? Updated_At { get; set; }
 }
 
 
diff --git a/C#api/models/items.cs b/C#api/models/items.cs
index 8d3adc2..d814a28 100644
--- a/C#api/models/items.cs
+++ b/C#api/models/items.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq;
 using Newtonsoft.Json;
+using Providers;
 namespace Models;
 
 
@@ -24,8 +25,8 @@ public class Item
     public int Supplier_Id { get; set; }
     public string Supplier_Code { get; set; }
     public string Supplier_Part_Number { get; set; }
-    public string Created_At { get; set; }
-    public string Updated_At { get; set; }
+    public string? Created_At { get; set; }
+    public string? Updated_At { get; set; }
 }
 
 public class Items : Base
diff --git a/C#api/models/locations.cs b/C#api/models/locations.cs
index 7b69464..0bc951f 100644
--- a/C#api/models/locations.cs
+++ b/C#api/models/locations.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq;
 using Newtonsoft.Json;
+using Providers;
 namespace Models;
 
 public class Location
@@ -11,8 +12,8 @@ public class Location
     public int Warehouse_Id { get; set; }
     public string Code { get; set; }
     public string Name { get; set; }
-    public string Created_At { get; set; }
-    public string Updated_At { get; set; }
+    public string? Created_At { get; set; }
+    public string? Updated_At { get; set; }
 }
 
 public class Locations : Base
diff --git a/C#api/models/orders.cs b/C#api/models/orders.cs
index 3157b7c..e34d93e 100644
--- a/C#api/models/orders.cs
+++ b/C#api/models/orders.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq;
 using Newtonsoft.Json;
+using Providers;
 namespace Models;
 
 public class OrderItem
@@ -31,8 +32,8 @@ public class Order
     public decimal Total_Discount { get; set; }
     public decimal Total_Tax { get; set; }
     public decimal Total_Surcharge { get; set; }
-    public string Created_At { get; set; }
-    public string Updated_At { get; set; }
+    public string? Created_At { get; set; }
+    public string? Updated_At { get; set; }
     public List<OrderItem> Items { get; set; }
 }
 
diff --git a/C#api/models/shipments.cs b/C#api/models/shipments.cs
index 2ce5c20..5301adb 100644
--- a/C#api/models/shipments.cs
+++ b/C#api/models/shipments.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq;
 namespace Models;
+using Providers;
 using Newtonsoft.Json;
 
 public class ShipmentItem
@@ -28,8 +29,8 @@ public class Shipment
     public string Transfer_Mode { get; set; }
     public int Total_Package_Count { get; set; }
     public double Total_Package_Weight { get; set; }
-    public string Created_At { get; set; }
-    public string Updated_At { get; set; }
+    public string? Created_At { get; set; }
+    public string? Updated_At { get; set; }
     public List<ShipmentItem> Items { get; set; }
 }
 
diff --git a/C#api/models/suppliers.cs b/C#api/models/suppliers.cs
index 6c8c4f2..87f293e 100644
--- a/C#api/models/suppliers.cs
+++ b/C#api/models/suppliers.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq;
 namespace Models;
+using Providers;
 using Newtonsoft.Json;
 
 public class Supplier
@@ -19,8 +20,8 @@ public class Supplier
     public string Contact_Name { get; set; }
     public string Phonenumber { get; set; }
     public string Reference { get; set; }
-    public string Created_At { get; set; }
-    public string Updated_At { get; set; }
+    public string? Created_At { get; set; }
+    public string? Updated_At { get; set; }
 }
 
 public class Suppliers : Base
diff --git a/C#api/models/transfers.cs b/C#api/models/transfers.cs
index 597d203..b9beee1 100644
--- a/C#api/models/transfers.cs
+++ b/C#api/models/transfers.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq;
 namespace Models;
+using Providers;
 using Newtonsoft.Json;
 
 public class TransferItem
@@ -17,8 +18,8 @@ public class Transfer
     public int? Transfer_From { get; set; } 
     public int? Transfer_To { get; set; }
     public string Transfer_Status { get; set; }
-    public string Created_At { get; set; }
-    public string Updated_At { get; set; }
+    public string? Created_At { get; set; }
+    public string? Updated_At { get; set; }
     public List<TransferItem> Items { get; set; }
 }
 
diff --git a/C#api/models/warehouses.cs b/C#api/models/warehouses.cs
index 4410e2b..31c3e27 100644
--- a/C#api/models/warehouses.cs
+++ b/C#api/models/warehouses.cs
@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq;
 namespace Models;
+using Providers;
 using Newtonsoft.Json; // Ensure you have Newtonsoft.Json package installed
 
 public class ContactInfo
@@ -22,8 +23,8 @@ public class Warehouse
     public string Province { get; set; }
     public string Country { get; set; }
     public ContactInfo Contact { get; set; }
-    public string Created_At { get; set; }
-    public string Updated_At { get; set; }
+    public string? Created_At { get; set; }
+    public string? Updated_At { get; set; }
 
 }
 
diff --git a/C#api/providers/auth_provider.cs b/C#api/providers/auth_provider.cs
index 3823b31..2edf308 100644
--- a/C#api/providers/auth_provider.cs
+++ b/C#api/providers/auth_provider.cs
@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Linq;
+namespace Providers;
 
 public class AuthProvider
 {
diff --git a/C#api/providers/data_provider.cs b/C#api/providers/data_provider.cs
index a47d050..ca3b679 100644
--- a/C#api/providers/data_provider.cs
+++ b/C#api/providers/data_provider.cs
@@ -1,6 +1,7 @@
 using System;
 using Models;
 using System.IO;
+namespace Providers;
 
 class DataProvider
 {
diff --git a/Properties/launchSettings.json b/Properties/launchSettings.json
new file mode 100644
index 0000000..f518c8c
--- /dev/null
+++ b/Properties/launchSettings.json
@@ -0,0 +1,41 @@
+{
+  "$schema": "http://json.schemastore.org/launchsettings.json",
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:19115",
+      "sslPort": 44311
+    }
+  },
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "launchUrl": "swagger",
+      "applicationUrl": "http://localhost:5231",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "https": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "launchUrl": "swagger",
+      "applicationUrl": "https://localhost:7013;http://localhost:5231",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "launchUrl": "swagger",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}
diff --git a/Software-Construction.csproj b/Software-Construction.csproj
index aeea7e9..bb979ef 100644
--- a/Software-Construction.csproj
+++ b/Software-Construction.csproj
@@ -1,16 +1,16 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
     <TargetFramework>net8.0</TargetFramework>
-    <RootNamespace>Software_Construction</RootNamespace>
-    <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <RootNamespace>Software_Construction</RootNamespace>
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.8" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
-    <PackageReference Include="xunit" Version="2.9.2" />
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.4.0" />
   </ItemGroup>
 
 </Project>
diff --git a/Software-Construction.http b/Software-Construction.http
new file mode 100644
index 0000000..d5d9447
--- /dev/null
+++ b/Software-Construction.http
@@ -0,0 +1,6 @@
+@Software_Construction_HostAddress = http://localhost:5231
+
+GET {{Software_Construction_HostAddress}}/weatherforecast/
+Accept: application/json
+
+###
diff --git a/appsettings.Development.json b/appsettings.Development.json
new file mode 100644
index 0000000..0c208ae
--- /dev/null
+++ b/appsettings.Development.json
@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}
diff --git a/appsettings.json b/appsettings.json
new file mode 100644
index 0000000..10f68b8
--- /dev/null
+++ b/appsettings.json
@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}