diff --git a/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/ICollectBusinessLogicContract.cs b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/ICollectBusinessLogicContract.cs
new file mode 100644
index 0000000..07b1969
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/ICollectBusinessLogicContract.cs
@@ -0,0 +1,16 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.BusinessLogicsContracts;
+
+public interface ICollectBusinessLogicContract
+{
+    List<CollectDataModel> GetAllCollectByPeriod(DateTime fromDate, DateTime toDate);
+
+    List<CollectDataModel> GetAllCollectByWorkerByPeriod(string workerId, DateTime fromDate, DateTime toDate);
+
+    List<CollectDataModel> GetAllCollectsByFurnitureByPeriod(string furnitureId, DateTime fromDate, DateTime toDate);
+
+    CollectDataModel GetCollectByData(string data);
+
+    void InsertCollect(CollectDataModel collectDataModel);
+}
diff --git a/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IFurnitureBusinessLogicContract.cs b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IFurnitureBusinessLogicContract.cs
new file mode 100644
index 0000000..0fabfc3
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IFurnitureBusinessLogicContract.cs
@@ -0,0 +1,18 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.BusinessLogicsContracts;
+
+public interface IFurnitureBusinessLogicContract
+{
+    List<FurnitureDataModel> GetAllFurniture(bool onlyActive = true);
+
+    List<FurnitureHistoryDataModel> GetFurnitureHistoryByFurniture(string furnitureId);
+
+    FurnitureDataModel GetFurnitureByData(string data);
+
+    void InsertFurniture(FurnitureDataModel furnitureDataModel);
+
+    void UpdateFurniture(FurnitureDataModel furnitureDataModel);
+
+    void DeleteFurniture(string id);
+}
\ No newline at end of file
diff --git a/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IPostBusinessLogicContract.cs b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IPostBusinessLogicContract.cs
new file mode 100644
index 0000000..9d9d0cb
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IPostBusinessLogicContract.cs
@@ -0,0 +1,20 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.BusinessLogicsContracts;
+
+public interface IPostBusinessLogicContract
+{
+    List<PostDataModel> GetAllPosts(bool onlyActive);
+
+    List<PostDataModel> GetAllDataOfPost(string postId);
+
+    PostDataModel GetPostByData(string data);
+
+    void InsertPost(PostDataModel postDataModel);
+
+    void UpdatePost(PostDataModel postDataModel);
+
+    void DeletePost(string id);
+
+    void RestorePost(string id);
+}
diff --git a/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/ISalaryBusinessLogicContract.cs b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/ISalaryBusinessLogicContract.cs
new file mode 100644
index 0000000..6160ad5
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/ISalaryBusinessLogicContract.cs
@@ -0,0 +1,12 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.BusinessLogicsContracts;
+
+public interface ISalaryBusinessLogicContract
+{
+    List<SalaryDataModel> GetAllSalariesByPeriod(DateTime fromDate, DateTime toDate);
+
+    List<SalaryDataModel> GetAllSalariesByPeriodByWorker(DateTime fromDate, DateTime toDate, string workerId);
+
+    void CalculateSalaryByMonth(DateTime date);
+}
diff --git a/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IWorkPieceBusinessLogicContract.cs b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IWorkPieceBusinessLogicContract.cs
new file mode 100644
index 0000000..4e754e7
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IWorkPieceBusinessLogicContract.cs
@@ -0,0 +1,16 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.BusinessLogicsContracts;
+
+public interface IWorkPieceBusinessLogicContract
+{
+    List<WorkPieceDataModel> GetAllWorkPieces();
+
+    List<WorkPieceDataModel> GetWorkPiecesByData(string data);
+
+    void InsertPost(WorkPieceDataModel workPieceDataModel);
+
+    void UpdatePost(WorkPieceDataModel workPieceDataModel);
+
+    void DeletePost(string id);
+}
diff --git a/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IWorkerBusinessLogicContract.cs b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IWorkerBusinessLogicContract.cs
new file mode 100644
index 0000000..c59ad46
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/BusinessLogicsContracts/IWorkerBusinessLogicContract.cs
@@ -0,0 +1,22 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.BusinessLogicsContracts;
+
+public interface IWorkerBusinessLogicContract
+{
+    List<WorkerDataModel> GetAllWorkers();
+
+    List<WorkerDataModel> GetAllWorkersByPost(string postId);
+
+    List<WorkerDataModel> GetAllWorkersByBirthDate(DateTime fromDate, DateTime toDate);
+
+    List<WorkerDataModel> GetAllWorkersByEmploymentDate(DateTime fromDate, DateTime toDate);
+
+    WorkerDataModel GetWorkerByData(string data);
+
+    void InsertWorker(WorkerDataModel workerDataModel);
+
+    void UpdateWorker(WorkerDataModel workerDataModel);
+
+    void DeleteWorker(string id);
+}
diff --git a/TheSoftBedProject/SoftBedContracts/StoragesContracts/ICollectStorageContract.cs b/TheSoftBedProject/SoftBedContracts/StoragesContracts/ICollectStorageContract.cs
new file mode 100644
index 0000000..ea8512f
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/StoragesContracts/ICollectStorageContract.cs
@@ -0,0 +1,14 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.StoragesContracts;
+
+public interface ICollectStorageContract
+{
+    List<CollectDataModel> GetList(DateTime? startDate = null, DateTime? endDate = null, string? workerId = null, string? furnitureId = null);
+
+    CollectDataModel? GetElementById(string id);
+
+    void AddElement(CollectDataModel collectDataModel);
+
+    void DelElement(string id);
+}
diff --git a/TheSoftBedProject/SoftBedContracts/StoragesContracts/IFurnitureStorageContract.cs b/TheSoftBedProject/SoftBedContracts/StoragesContracts/IFurnitureStorageContract.cs
new file mode 100644
index 0000000..1fb5c44
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/StoragesContracts/IFurnitureStorageContract.cs
@@ -0,0 +1,20 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.StoragesContracts;
+
+public interface IFurnitureStorageContract
+{
+    List<FurnitureDataModel> GetList(bool onlyActive = true);
+
+    List<FurnitureDataModel> GetHistoryByFurnitureId(string furnitureId);
+
+    FurnitureDataModel? GetElementById(string id);
+
+    FurnitureDataModel? GetElementByName(string name);
+
+    void AddElement(FurnitureDataModel furnitureDataModel);
+
+    void UpdElement(FurnitureDataModel furnitureDataModel);
+
+    void DelElement(string id);
+}
diff --git a/TheSoftBedProject/SoftBedContracts/StoragesContracts/IPostStorageContarct.cs b/TheSoftBedProject/SoftBedContracts/StoragesContracts/IPostStorageContarct.cs
new file mode 100644
index 0000000..ee4c3b7
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/StoragesContracts/IPostStorageContarct.cs
@@ -0,0 +1,22 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.StoragesContracts;
+
+public interface IPostStorageContract
+{
+    List<PostDataModel> GetList(bool onlyActual = true);
+
+    List<PostDataModel> GetPostWithHistory(string postId);
+
+    PostDataModel? GetElementById(string id);
+
+    PostDataModel? GetElementByName(string name);
+
+    void AddElement(PostDataModel postDataModel);
+
+    void UpdElement(PostDataModel postDataModel);
+
+    void DelElement(string id);
+
+    void ResElement(string id);
+}
diff --git a/TheSoftBedProject/SoftBedContracts/StoragesContracts/ISalaryStorageContract.cs b/TheSoftBedProject/SoftBedContracts/StoragesContracts/ISalaryStorageContract.cs
new file mode 100644
index 0000000..6e3c4ae
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/StoragesContracts/ISalaryStorageContract.cs
@@ -0,0 +1,10 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.StoragesContracts;
+
+public interface ISalaryStorageContract
+{
+    List<SalaryDataModel> GetList(DateTime startDate, DateTime endDate, string? workerId = null);
+
+    void AddElement(SalaryDataModel salaryDataModel);
+}
diff --git a/TheSoftBedProject/SoftBedContracts/StoragesContracts/IWorkPieceStorageContract.cs b/TheSoftBedProject/SoftBedContracts/StoragesContracts/IWorkPieceStorageContract.cs
new file mode 100644
index 0000000..59df345
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/StoragesContracts/IWorkPieceStorageContract.cs
@@ -0,0 +1,18 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.StoragesContracts;
+
+public interface IWorkPieceStorageContract
+{
+    List<WorkPieceDataModel> GetList();
+
+    WorkPieceDataModel? GetElementById(string id);
+
+    WorkPieceDataModel? GetElementBySize(string size);
+
+    void AddElement(WorkPieceDataModel workPieceDataModel);
+
+    void UpdElement(WorkPieceDataModel workPieceDataModel);
+
+    void DelElement(string id);
+}
diff --git a/TheSoftBedProject/SoftBedContracts/StoragesContracts/IWorkerStorageContract.cs b/TheSoftBedProject/SoftBedContracts/StoragesContracts/IWorkerStorageContract.cs
new file mode 100644
index 0000000..0e9a46f
--- /dev/null
+++ b/TheSoftBedProject/SoftBedContracts/StoragesContracts/IWorkerStorageContract.cs
@@ -0,0 +1,18 @@
+using SoftBedContracts.DataModels;
+
+namespace SoftBedContracts.StoragesContracts;
+
+public interface IWorkerStorageContract
+{
+    List<WorkerDataModel> GetList(string? postId = null, DateTime? fromBirthDate = null, DateTime? toBirthDate = null, DateTime? fromEmploymentDate = null, DateTime? toEmploymentDate = null);
+
+    WorkerDataModel? GetElementById(string id);
+
+    WorkerDataModel? GetElementByFIO(string fio);
+
+    void AddElement(WorkerDataModel workerDataModel);
+
+    void UpdElement(WorkerDataModel workerDataModel);
+
+    void DelElement(string id);
+}