diff --git a/PuferFishContracts/PuferFishBusinessLogic/Implementations/BuyerBusinessLogicContract.cs b/PuferFishContracts/PuferFishBusinessLogic/Implementations/BuyerBusinessLogicContract.cs
new file mode 100644
index 0000000..aa3766e
--- /dev/null
+++ b/PuferFishContracts/PuferFishBusinessLogic/Implementations/BuyerBusinessLogicContract.cs
@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using PuferFishContracts.BusinessLogicsContracts;
+using PuferFishContracts.DataModels;
+using PuferFishContracts.StoragesContracts;
+
+namespace PuferFishBusinessLogic.Implementationsж
+{
+    internal class BuyerBusinessLogicContract(IBuyerStorageContract buyerStorageContract, ILogger logger) : IBuyerBusinessLogicContract
+    {
+        private readonly ILogger _logger = logger;
+        private readonly IBuyerStorageContract _buyerStorageContract =
+        buyerStorageContract;
+        public List<BuyerDataModel> GetAllBuyers()
+        {
+            return [];
+        }
+        public BuyerDataModel GetBuyerByData(string data)
+        {
+            return new("", "", "", 0);
+        }
+        public void InsertBuyer(BuyerDataModel buyerDataModel)
+        {
+        }
+        public void UpdateBuyer(BuyerDataModel buyerDataModel)
+        {
+        }
+        public void DeleteBuyer(string id)
+        {
+        }
+    }
+}
diff --git a/PuferFishContracts/PuferFishBusinessLogic/Implementations/PointsBusinessLogicContract.cs b/PuferFishContracts/PuferFishBusinessLogic/Implementations/PointsBusinessLogicContract.cs
new file mode 100644
index 0000000..0035c19
--- /dev/null
+++ b/PuferFishContracts/PuferFishBusinessLogic/Implementations/PointsBusinessLogicContract.cs
@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using PuferFishContracts.BusinessLogicsContracts;
+using PuferFishContracts.DataModels;
+using PuferFishContracts.StoragesContracts;
+
+namespace PuferFishBusinessLogic.Implementations;
+
+internal class PointsBusinessLogicContract(IPointsStorageContract pointsStorageContract, ISaleStorageContract saleStorageContract, IPostStorageContract
+postStorageContract, IBuyerStorageContract buyerStorageContract, ILogger logger) : IPointsBusinessLogicContract
+{
+    private readonly ILogger _logger = logger;
+    private readonly IPointsStorageContract _pointsStorageContract = pointsStorageContract;
+    private readonly ISaleStorageContract _saleStorageContract = saleStorageContract;
+    private readonly IPostStorageContract _postStorageContract = postStorageContract;
+    private readonly IBuyerStorageContract _buyerStorageContract = buyerStorageContract;
+    public List<PointsDataModel> GetAllPointsByPeriod(DateTime fromDate,
+    DateTime toDate)
+    {
+        return [];
+    }
+    public List<PointsDataModel> GetAllPointsByPeriodByBuyer(DateTime fromDate, DateTime toDate, string buyerId)
+    {
+        return [];
+    }
+    public void CalculatePointsByMounth(DateTime date)
+    {
+    }
+}
diff --git a/PuferFishContracts/PuferFishBusinessLogic/Implementations/PostBusinessLogicContract.cs b/PuferFishContracts/PuferFishBusinessLogic/Implementations/PostBusinessLogicContract.cs
new file mode 100644
index 0000000..32beec4
--- /dev/null
+++ b/PuferFishContracts/PuferFishBusinessLogic/Implementations/PostBusinessLogicContract.cs
@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using PuferFishContracts.BusinessLogicsContracts;
+using PuferFishContracts.DataModels;
+using PuferFishContracts.Enums;
+using PuferFishContracts.StoragesContracts;
+
+namespace PuferFishBusinessLogic.Implementations;
+
+internal class PostBusinessLogicContract(IPostStorageContract postStorageContract, ILogger logger) : IPostBusinessLogicContract
+{
+    private readonly ILogger _logger = logger;
+    private readonly IPostStorageContract _postStorageContract =
+    postStorageContract;
+    public List<PostDataModel> GetAllPosts(bool onlyActive = true)
+    {
+        return [];
+    }
+    public List<PostDataModel> GetAllDataOfPost(string postId)
+    {
+        return [];
+    }
+    public PostDataModel GetPostByData(string data)
+    {
+        return new("", "", PostType.None, 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/PuferFishContracts/PuferFishBusinessLogic/Implementations/ProductBusinessLogicContract.cs b/PuferFishContracts/PuferFishBusinessLogic/Implementations/ProductBusinessLogicContract.cs
new file mode 100644
index 0000000..1c12f6a
--- /dev/null
+++ b/PuferFishContracts/PuferFishBusinessLogic/Implementations/ProductBusinessLogicContract.cs
@@ -0,0 +1,45 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using PuferFishContracts.BusinessLogicsContracts;
+using PuferFishContracts.DataModels;
+using PuferFishContracts.Enums;
+using PuferFishContracts.StoragesContracts;
+
+namespace PuferFishBusinessLogic.Implementations;
+
+internal class ProductBusinessLogicContract(IProductStorageContract productStorageContract, ILogger logger) : IProductBusinessLogicContract
+{
+    private readonly ILogger _logger = logger;
+    private readonly IProductStorageContract _productStorageContract =
+productStorageContract;
+    public List<ProductDataModel> GetAllProducts(bool onlyActive)
+    {
+        return [];
+    }
+    public List<ProductDataModel> GetAllProductsByManufacturer(string
+    manufacturerId, 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/PuferFishContracts/PuferFishBusinessLogic/Implementations/SaleBusinessLogicContract.cs b/PuferFishContracts/PuferFishBusinessLogic/Implementations/SaleBusinessLogicContract.cs
new file mode 100644
index 0000000..96508f6
--- /dev/null
+++ b/PuferFishContracts/PuferFishBusinessLogic/Implementations/SaleBusinessLogicContract.cs
@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using PuferFishContracts.BusinessLogicsContracts;
+using PuferFishContracts.DataModels;
+using PuferFishContracts.StoragesContracts;
+
+namespace PuferFishBusinessLogic.Implementations;
+
+internal class SaleBusinessLogicContract(ISaleStorageContract saleStorageContract, ILogger logger) : ISaleBusinessLogicContract
+{
+    private readonly ILogger _logger = logger;
+    private readonly ISaleStorageContract _saleStorageContract =
+    saleStorageContract;
+    public List<SaleDataModel> GetAllSalesByPeriod(DateTime fromDate, DateTime
+    toDate)
+    {
+        return [];
+    }
+    public List<SaleDataModel> GetAllSalesByWorkerByPeriod(string workerId,
+    DateTime fromDate, DateTime toDate)
+    {
+        return [];
+    }
+    public List<SaleDataModel> GetAllSalesByBuyerByPeriod(string? buyerId,
+    DateTime fromDate, DateTime toDate)
+    {
+        return [];
+    }
+    public List<SaleDataModel> GetAllSalesByProductByPeriod(string productId,
+    DateTime fromDate, DateTime toDate)
+    {
+        return [];
+    }
+    public SaleDataModel GetSaleByData(string data)
+    {
+        return new("", "", "", 0, 0, false, []);
+    }
+    public void InsertSale(SaleDataModel saleDataModel)
+    {
+    }
+    public void CancelSale(string id)
+    {
+    }
+}
diff --git a/PuferFishContracts/PuferFishBusinessLogic/Implementations/WorkerBusinessLogicContract.cs b/PuferFishContracts/PuferFishBusinessLogic/Implementations/WorkerBusinessLogicContract.cs
new file mode 100644
index 0000000..27617da
--- /dev/null
+++ b/PuferFishContracts/PuferFishBusinessLogic/Implementations/WorkerBusinessLogicContract.cs
@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using PuferFishContracts.BusinessLogicsContracts;
+using PuferFishContracts.DataModels;
+using PuferFishContracts.StoragesContracts;
+
+namespace PuferFishBusinessLogic.Implementations;
+
+internal class WorkerBusinessLogicContract(IWorkerStorageContract workerStorageContract, ILogger logger) : IWorkerBusinessLogicContract
+{
+    private readonly ILogger _logger = logger;
+    private readonly IWorkerStorageContract _workerStorageContract =
+    workerStorageContract;
+    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/PuferFishContracts/PuferFishBusinessLogic/PuferFishBusinessLogic.csproj b/PuferFishContracts/PuferFishBusinessLogic/PuferFishBusinessLogic.csproj
new file mode 100644
index 0000000..0adc9e6
--- /dev/null
+++ b/PuferFishContracts/PuferFishBusinessLogic/PuferFishBusinessLogic.csproj
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\PuferFishContracts\PuferFishContracts.csproj" />
+  </ItemGroup>
+
+</Project>
diff --git a/PuferFishContracts/PuferFishContracts.sln b/PuferFishContracts/PuferFishContracts.sln
index 7378568..367e681 100644
--- a/PuferFishContracts/PuferFishContracts.sln
+++ b/PuferFishContracts/PuferFishContracts.sln
@@ -7,6 +7,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PuferFishContracts", "Pufer
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PuferFishTests", "PuferFishTests\PuferFishTests.csproj", "{6A249C1E-4321-4506-841B-2BCE80F550A5}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PuferFishBusinessLogic", "PuferFishBusinessLogic\PuferFishBusinessLogic.csproj", "{6997CEC9-5AB7-40C0-9873-E51D2674187B}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -21,6 +23,10 @@ Global
 		{6A249C1E-4321-4506-841B-2BCE80F550A5}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{6A249C1E-4321-4506-841B-2BCE80F550A5}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{6A249C1E-4321-4506-841B-2BCE80F550A5}.Release|Any CPU.Build.0 = Release|Any CPU
+		{6997CEC9-5AB7-40C0-9873-E51D2674187B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6997CEC9-5AB7-40C0-9873-E51D2674187B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6997CEC9-5AB7-40C0-9873-E51D2674187B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6997CEC9-5AB7-40C0-9873-E51D2674187B}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE