diff --git a/PipingHot/PipingHotBusinessLogic/Implementations/OrderBusinessLogicContract.cs b/PipingHot/PipingHotBusinessLogic/Implementations/OrderBusinessLogicContract.cs
new file mode 100644
index 0000000..b21d83e
--- /dev/null
+++ b/PipingHot/PipingHotBusinessLogic/Implementations/OrderBusinessLogicContract.cs
@@ -0,0 +1,42 @@
+using PipingHotContrast.BusinessLogicsContracts;
+using PipingHotContrast.DataModels;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace PipingHotBusinessLogic.Implementations;
+
+internal class OrderBusinessLogicContract : IOrderBusinessLogicContract
+{
+    public List<OrderDataModel> GetAllOrdersByPeriod(DateTime fromDate, DateTime toDate)
+    {
+        return [];
+    }
+    public List<OrderDataModel> GetAllOrdersByWorkerByPeriod(string workerId, DateTime fromDate, DateTime toDate)
+    {
+        return [];
+    }
+    public List<OrderDataModel> GetAllOrdersByRestaurantByPeriod(string restaurantId, DateTime fromDate, DateTime toDate)
+    {
+        return [];
+    }
+    public List<OrderDataModel> GetAllOrdersByProductByPeriod(string productId, DateTime fromDate, DateTime toDate)
+    {
+        return [];
+    }
+    public OrderDataModel GetOrderByData(string data)
+    {
+        return new("", "", "", 0,  true, []);
+    }
+
+    public void InsertOrder(OrderDataModel orderDataModel)
+    {
+        
+    }
+    public void CancelOrder(string id)
+    {
+        
+    }
+}
diff --git a/PipingHot/PipingHotBusinessLogic/Implementations/PostBusinessLogicContract.cs b/PipingHot/PipingHotBusinessLogic/Implementations/PostBusinessLogicContract.cs
new file mode 100644
index 0000000..1a1cf58
--- /dev/null
+++ b/PipingHot/PipingHotBusinessLogic/Implementations/PostBusinessLogicContract.cs
@@ -0,0 +1,47 @@
+using PipingHotContrast.BusinessLogicsContracts;
+using PipingHotContrast.DataModels;
+using PipingHotContrast.Enums;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace PipingHotBusinessLogic.Implementations;
+
+internal class PostBusinessLogicContract : IPostBusinessLogicContract
+{  
+    public List<PostDataModel> GetAllPosts(bool onlyActive)
+    {
+        return [];
+    }
+
+    public List<PostDataModel> GetAllDataOfPost(string postId)
+    {
+        return [];
+    }
+    public PostDataModel GetPostByData(string data)
+    {
+        return new("", "","", PostType.None, 0, true, DateTime.UtcNow);
+    }
+
+    public void InsertPost(PostDataModel postDataModel)
+    {
+        
+    }
+    public void UpdatePost(PostDataModel postDataModel)
+    {
+        
+    }
+    public void DeletePost(string id)
+    {
+        
+    }
+
+    public void RestorePost(string id)
+    {
+        
+    }
+
+    
+}
diff --git a/PipingHot/PipingHotBusinessLogic/Implementations/ProductBusinessLogicContract.cs b/PipingHot/PipingHotBusinessLogic/Implementations/ProductBusinessLogicContract.cs
new file mode 100644
index 0000000..5bc0d5a
--- /dev/null
+++ b/PipingHot/PipingHotBusinessLogic/Implementations/ProductBusinessLogicContract.cs
@@ -0,0 +1,44 @@
+using PipingHotContrast.BusinessLogicsContracts;
+using PipingHotContrast.DataModels;
+using PipingHotContrast.Enums;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace PipingHotBusinessLogic.Implementations;
+
+internal class ProductBusinessLogicContract : IProductBusinessLogicContract
+{
+    public List<ProductDataModel> GetAllProducts(bool onlyActive = true)
+    {
+        return [];
+    }
+
+    public List<ProductDataModel> GetAllProductsByRestaurant(string restaurantId, bool onlyActive = true)
+    {
+        return [];
+    }
+    public List<ProductHistoryDataModel> GetProductHistoryByProduct(string productId)
+    {
+        return [];
+    }
+    public ProductDataModel GetProductByData(string data)
+    {
+        return new("", "", ProductType.None, "", 0, true);
+    }
+    public void InsertProduct(ProductDataModel productDataModel)
+    {
+       
+    }
+
+    public void UpdateProduct(ProductDataModel productDataModel)
+    {
+       
+    }
+    public void DeleteProduct(string id)
+    {
+        
+    }
+}
diff --git a/PipingHot/PipingHotBusinessLogic/Implementations/RestaurantBusinessLogicContract.cs b/PipingHot/PipingHotBusinessLogic/Implementations/RestaurantBusinessLogicContract.cs
new file mode 100644
index 0000000..71313ef
--- /dev/null
+++ b/PipingHot/PipingHotBusinessLogic/Implementations/RestaurantBusinessLogicContract.cs
@@ -0,0 +1,37 @@
+
+using PipingHotContrast.BusinessLogicsContracts;
+using PipingHotContrast.DataModels;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace PipingHotBusinessLogic.Implementations;
+
+internal class RestaurantBusinessLogicContract : IRestaurantBusinessLogicContract
+{ 
+    public List<RestaurantDataModel> GetAllRestaurants()
+    {
+        return [];
+    }
+
+    public RestaurantDataModel GetRestaurantByData(string data)
+    {
+        return new("", "", null, null);
+    }
+
+    public void InsertRestaurant(RestaurantDataModel restaurantDataModel)
+    {
+        
+    }
+
+    public void UpdateRestaurant(RestaurantDataModel restaurantDataModel)
+    {
+        
+    }
+    public void DeleteRestaurant(string id)
+    {
+        
+    }
+}
diff --git a/PipingHot/PipingHotBusinessLogic/Implementations/SalaryBusinessLogicContract.cs b/PipingHot/PipingHotBusinessLogic/Implementations/SalaryBusinessLogicContract.cs
new file mode 100644
index 0000000..bdd6b01
--- /dev/null
+++ b/PipingHot/PipingHotBusinessLogic/Implementations/SalaryBusinessLogicContract.cs
@@ -0,0 +1,26 @@
+using PipingHotContrast.BusinessLogicsContracts;
+using PipingHotContrast.DataModels;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace PipingHotBusinessLogic.Implementations;
+
+internal class SalaryBusinessLogicContract : ISalaryBusinessLogicContract
+{
+    public List<SalaryDataModel> GetAllSalariesByPeriod(DateTime fromDate, DateTime toDate)
+    {
+        return [];
+    }
+
+    public List<SalaryDataModel> GetAllSalariesByPeriodByWorker(DateTime fromDate, DateTime toDate, string workerId)
+    {
+        return [];
+    }
+    public void CalculateSalaryByMounth(DateTime date)
+    {
+        
+    }
+}
diff --git a/PipingHot/PipingHotBusinessLogic/Implementations/WorkerBusinessLogicContract.cs b/PipingHot/PipingHotBusinessLogic/Implementations/WorkerBusinessLogicContract.cs
new file mode 100644
index 0000000..3aab982
--- /dev/null
+++ b/PipingHot/PipingHotBusinessLogic/Implementations/WorkerBusinessLogicContract.cs
@@ -0,0 +1,48 @@
+using PipingHotContrast.BusinessLogicsContracts;
+using PipingHotContrast.DataModels;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace PipingHotBusinessLogic.Implementations;
+
+internal class WorkerBusinessLogicContract : IWorkerBusinessLogicContract
+{
+    public List<WorkerDataModel> GetAllWorkers(bool onlyActive = true)
+    {
+        return [];
+    }
+    public List<WorkerDataModel> GetAllWorkersByPost(string postId, bool onlyActive = true)
+    {
+        return [];
+    }
+    public List<WorkerDataModel> GetAllWorkersByBirthDate(DateTime fromDate, DateTime toDate, bool onlyActive = true)
+    {
+        return [];
+    }
+
+    public List<WorkerDataModel> GetAllWorkersByEmploymentDate(DateTime fromDate, DateTime toDate, bool onlyActive = true)
+    {
+        return [];
+    }
+    public WorkerDataModel GetWorkerByData(string data)
+    {
+        return new("", "", "","", DateTime.Now, DateTime.Now, true);
+    }
+
+    public void InsertWorker(WorkerDataModel workerDataModel)
+    {
+        
+    }
+
+    public void UpdateWorker(WorkerDataModel workerDataModel)
+    {
+       
+    }
+    public void DeleteWorker(string id)
+    {
+        
+    }
+}
diff --git a/PipingHot/PipingHotBusinessLogic/PipingHotBusinessLogic.csproj b/PipingHot/PipingHotBusinessLogic/PipingHotBusinessLogic.csproj
new file mode 100644
index 0000000..ac07c5b
--- /dev/null
+++ b/PipingHot/PipingHotBusinessLogic/PipingHotBusinessLogic.csproj
@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0-windows</TargetFramework>
+    <Nullable>enable</Nullable>
+    <UseWPF>true</UseWPF>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+</Project>