Добавил контроллеры

Payments/Payment.WebApi/Controllers/SupplierController.cs

+using Microsoft.AspNetCore.Mvc;
+using Payment.WebApi.Models.DbModels;
+using Payment.WebApi.Repositories.Interfaces;
+
+namespace Payment.WebApi.Controllers;
+
+[ApiController]
+public class SupplierController : Controller
+{
+    private readonly ISupplierRepository _supplierRepository;
+
+    public SupplierController(ISupplierRepository supplierRepository)
+    {
+        _supplierRepository = supplierRepository;
+    }
+
+    public ActionResult<List<Supplier>> GetAll()
+    {
+        try
+        {
+            return Ok(_supplierRepository.GetAll());
+        }
+        catch (Exception e)
+        {
+            return StatusCode(500, new { errorMessage = e.Message });
+        }
+    }
+}
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Payments/Payment.WebApi/Controllers/UserController.cs

+using Microsoft.AspNetCore.Mvc;
+using Payment.WebApi.Models.DbModels;
+using Payment.WebApi.Repositories.Interfaces;
+
+namespace Payment.WebApi.Controllers;
+
+[ApiController]
+public class UserController : Controller
+{
+    private readonly IUserRepository _userRepository;
+
+    public UserController(IUserRepository userRepository)
+    {
+        _userRepository = userRepository;
+    }
+
+    public ActionResult<User> GetUser(int id)
+    {
+        try
+        {
+            var user = _userRepository.GetFirstOrDefaultById(id);
+            if (user is null)
+                return NotFound();
+
+            return Ok(user);
+        }
+        catch (Exception e)
+        {
+            return StatusCode(500, new { errorMessage = e.Message });
+        }
+    }
+}
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