diff --git a/Inflow.Domain/Intefaces/Services/ICategoryService.cs b/Inflow.Domain/Intefaces/Services/ICategoryService.cs
new file mode 100644
index 0000000..a9b8170
--- /dev/null
+++ b/Inflow.Domain/Intefaces/Services/ICategoryService.cs
@@ -0,0 +1,16 @@
+using Inflow.Domain.DTOs.Category;
+using Inflow.Domain.ResourceParameters;
+using Inflow.Domain.Responses;
+
+namespace Inflow.Domain.Interfaces.Services
+{
+    public interface ICategoryService
+    {
+        IEnumerable<CategoryDto> GetAllCategories();
+        GetBaseResponse<CategoryDto> GetCategories(CategoryResourceParameters categoryResourceParameters);
+        CategoryDto? GetCategoryById(int id);
+        CategoryDto CreateCategory(CategoryForCreateDto categoryToCreate);
+        CategoryDto UpdateCategory(CategoryForUpdateDto categoryToUpdate);
+        void DeleteCategory(int id);
+    }
+}
diff --git a/Inflow.Domain/Intefaces/Services/ICustomerService.cs b/Inflow.Domain/Intefaces/Services/ICustomerService.cs
new file mode 100644
index 0000000..91402aa
--- /dev/null
+++ b/Inflow.Domain/Intefaces/Services/ICustomerService.cs
@@ -0,0 +1,17 @@
+using Inflow.Domain.DTOs.Customer;
+using Inflow.Domain.Pagniation;
+using Inflow.Domain.ResourceParameters;
+using Inflow.Domain.Responses;
+
+namespace Inflow.Domain.Interfaces.Services
+{
+    public interface ICustomerService
+    {
+        IEnumerable<CustomerDto> GetCustomers();
+        GetBaseResponse<CustomerDto> GetCustomers(CustomerResourceParameters customerResourceParameters);
+        CustomerDto? GetCustomerById(int id);
+        CustomerDto CreateCustomer(CustomerForCreateDto customerToCreate);
+        CustomerDto UpdateCustomer(CustomerForUpdateDto customerToUpdate);
+        void DeleteCustomer(int id);
+    }
+}
diff --git a/Inflow.Domain/Intefaces/Services/IDashboardService.cs b/Inflow.Domain/Intefaces/Services/IDashboardService.cs
new file mode 100644
index 0000000..200e2e3
--- /dev/null
+++ b/Inflow.Domain/Intefaces/Services/IDashboardService.cs
@@ -0,0 +1,9 @@
+using Inflow.Domain.DTOs.Dashboard;
+
+namespace Inflow.Domain.Interfaces.Services
+{
+    public interface IDashboardService
+    {
+        DashboardDto GetDashboard();
+    }
+}
diff --git a/Inflow.Domain/Intefaces/Services/IProductService.cs b/Inflow.Domain/Intefaces/Services/IProductService.cs
new file mode 100644
index 0000000..2ca066f
--- /dev/null
+++ b/Inflow.Domain/Intefaces/Services/IProductService.cs
@@ -0,0 +1,17 @@
+using Inflow.Domain.DTOs.Product;
+using Inflow.Domain.Pagniation;
+using Inflow.Domain.Responses;
+using Inflow.ResourceParameters;
+
+namespace Inflow.Domain.Interfaces.Services
+{
+    public interface IProductService
+    {
+        IEnumerable<ProductDto> GetAllProducts();
+        GetBaseResponse<ProductDto> GetProducts(ProductResourceParameters productResourceParameters);
+        ProductDto? GetProductById(int id);
+        ProductDto CreateProduct(ProductForCreateDto productToCreate);
+        void UpdateProduct(ProductForUpdateDto productToUpdate);
+        void DeleteProduct(int id);
+    }
+}
diff --git a/Inflow.Domain/Intefaces/Services/ISaleItemService.cs b/Inflow.Domain/Intefaces/Services/ISaleItemService.cs
new file mode 100644
index 0000000..d558bf1
--- /dev/null
+++ b/Inflow.Domain/Intefaces/Services/ISaleItemService.cs
@@ -0,0 +1,24 @@
+using Inflow.Domain.DTOs.Category;
+using Inflow.Domain.DTOs.SaleItem;
+using Inflow.Domain.Pagniation;
+using Inflow.Domain.ResourceParameters;
+using Inflow.Domain.Responses;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Inflow.Domain.Interfaces.Services
+{
+    public interface ISaleItemService
+    {
+        IEnumerable<SaleItemDto> GetAllSaleItems();
+        IEnumerable<SaleItemDto> GetSalesSaleItems(int salesId);
+        GetBaseResponse<SaleItemDto> GetSaleItems(SaleItemResourceParameters saleItemResourceParameters);
+        SaleItemDto? GetSaleItemById(int id);
+        SaleItemDto CreateSaleItem(SaleItemForCreateDto saleItemToCreate);
+        void UpdateSaleItem(SaleItemForUpdateDto saleItemToUpdate);
+        void DeleteSaleItem(int id);
+    }
+}
diff --git a/Inflow.Domain/Intefaces/Services/ISaleService.cs b/Inflow.Domain/Intefaces/Services/ISaleService.cs
new file mode 100644
index 0000000..8e35697
--- /dev/null
+++ b/Inflow.Domain/Intefaces/Services/ISaleService.cs
@@ -0,0 +1,18 @@
+using Inflow.Domain.DTOs.Sale;
+using Inflow.Domain.Pagniation;
+using Inflow.Domain.ResourceParameters;
+using Inflow.Domain.Responses;
+
+namespace Inflow.Domain.Interfaces.Services
+{
+    public interface ISaleService
+    {
+        IEnumerable<SaleDto> GetAllSales();
+        IEnumerable<SaleDto> GetCustomersSale(int customersId);
+        GetBaseResponse<SaleDto> GetSales(SaleResourceParameters saleResourceParameters);
+        SaleDto? GetSaleById(int id);
+        SaleDto CreateSale(SaleForCreateDto saleToCreate);
+        void UpdateSale(SaleForUpdateDto saleToUpdate);
+        void DeleteSale(int id);
+    }
+}
diff --git a/Inflow.Domain/Intefaces/Services/ISupplierService.cs b/Inflow.Domain/Intefaces/Services/ISupplierService.cs
new file mode 100644
index 0000000..e5ba4a0
--- /dev/null
+++ b/Inflow.Domain/Intefaces/Services/ISupplierService.cs
@@ -0,0 +1,17 @@
+using Inflow.Domain.DTOs.Supplier;
+using Inflow.Domain.Pagniation;
+using Inflow.Domain.ResourceParameters;
+using Inflow.Domain.Responses;
+
+namespace Inflow.Domain.Interfaces.Services
+{
+    public interface ISupplierService
+    {
+        IEnumerable<SupplierDto> GetAllSuppliers();
+        GetBaseResponse<SupplierDto> GetSuppliers(SupplierResourceParameters supplierResourceParameters);
+        SupplierDto? GetSupplierById(int id);
+        SupplierDto CreateSupplier(SupplierForCreateDto supplierToCreate);
+        SupplierDto UpdateSupplier(SupplierForUpdateDto supplierToUpdate);
+        void DeleteSupplier(int id);
+    }
+}
diff --git a/Inflow.Domain/Intefaces/Services/ISupplyItemService.cs b/Inflow.Domain/Intefaces/Services/ISupplyItemService.cs
new file mode 100644
index 0000000..4cd5603
--- /dev/null
+++ b/Inflow.Domain/Intefaces/Services/ISupplyItemService.cs
@@ -0,0 +1,17 @@
+using Inflow.Domain.DTOs.SupplyItem;
+using Inflow.Domain.Pagniation;
+using Inflow.Domain.ResourceParameters;
+using Inflow.Domain.Responses;
+
+namespace Inflow.Domain.Interfaces.Services
+{
+    public interface ISupplyItemService
+    {
+        IEnumerable<SupplyItemDto> GetAllSupplyItems();
+        GetBaseResponse<SupplyItemDto> GetSupplyItems(SupplyItemResourceParameters supplyItemResourceParameters);
+        SupplyItemDto? GetSupplyItemById(int id);
+        SupplyItemDto CreateSupplyItem(SupplyItemForCreateDto supplyItemToCreate);
+        void UpdateSupplyItem(SupplyItemForUpdateDto supplyItemToUpdate);
+        void DeleteSupplyItem(int id);
+    }
+}
diff --git a/Inflow.Domain/Intefaces/Services/ISupplyService.cs b/Inflow.Domain/Intefaces/Services/ISupplyService.cs
new file mode 100644
index 0000000..6a2ebd2
--- /dev/null
+++ b/Inflow.Domain/Intefaces/Services/ISupplyService.cs
@@ -0,0 +1,18 @@
+using Inflow.Domain.DTOs.Category;
+using Inflow.Domain.DTOs.Supply;
+using Inflow.Domain.Pagniation;
+using Inflow.Domain.ResourceParameters;
+using Inflow.Domain.Responses;
+
+namespace Inflow.Domain.Interfaces.Services
+{
+    public interface ISupplyService
+    {
+        IEnumerable<SupplyDto> GetAllSupplies();
+        GetBaseResponse<SupplyDto> GetSupplies(SupplyResourceParameters supplyResourceParameters);
+        SupplyDto? GetSupplyById(int id);
+        SupplyDto CreateSupply(SupplyForCreateDto supplyToCreate);
+        void UpdateSupply(SupplyForUpdateDto supplyToUpdate);
+        void DeleteSupply(int id);
+    }
+}