diff --git a/Webshop.Api/Controllers/Public/CategorieController.cs b/Webshop.Api/Controllers/Public/CategorieController.cs
index 07fb737..a44ca88 100644
--- a/Webshop.Api/Controllers/Public/CategorieController.cs
+++ b/Webshop.Api/Controllers/Public/CategorieController.cs
@@ -1,8 +1,10 @@
 // src/Webshop.Api/Controllers/Public/categoriesController.cs
 using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using Webshop.Application;
 using Webshop.Application.DTOs.Categorie;
 using Webshop.Application.Services.Public;
 
@@ -21,18 +23,26 @@ namespace Webshop.Api.Controllers.Public
         }
 
         [HttpGet]
-        public async Task<ActionResult<IEnumerable<CategorieDto>>> GetActivecategories()
+        [ProducesResponseType(typeof(IEnumerable<CategorieDto>), StatusCodes.Status200OK)]
+        public async Task<IActionResult> GetActivecategories()
         {
-            var categories = await _categorieservice.GetAllActiveAsync();
-            return Ok(categories);
+            var result = await _categorieservice.GetAllActiveAsync();
+            return Ok(result.Value);
         }
 
         [HttpGet("{slug}")]
-        public async Task<ActionResult<CategorieDto>> GetcategorieBySlug(string slug)
+        [ProducesResponseType(typeof(CategorieDto), StatusCodes.Status200OK)]
+        [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
+        public async Task<IActionResult> GetcategorieBySlug(string slug)
         {
-            var categorie = await _categorieservice.GetBySlugAsync(slug);
-            if (categorie == null) return NotFound();
-            return Ok(categorie);
+            var result = await _categorieservice.GetBySlugAsync(slug);
+
+            return result.Type switch
+            {
+                ServiceResultType.Success => Ok(result.Value),
+                ServiceResultType.NotFound => NotFound(new { Message = result.ErrorMessage }),
+                _ => StatusCode(StatusCodes.Status500InternalServerError, "Ein unerwarteter Fehler ist aufgetreten.")
+            };
         }
     }
 }
\ No newline at end of file
diff --git a/Webshop.Application/Services/Public/CategorieService.cs b/Webshop.Application/Services/Public/CategorieService.cs
index fc35959..f32a3c6 100644
--- a/Webshop.Application/Services/Public/CategorieService.cs
+++ b/Webshop.Application/Services/Public/CategorieService.cs
@@ -2,7 +2,9 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using Webshop.Application;
 using Webshop.Application.DTOs.Categorie;
+using Webshop.Domain.Entities;
 using Webshop.Domain.Interfaces;
 
 namespace Webshop.Application.Services.Public
@@ -16,41 +18,41 @@ namespace Webshop.Application.Services.Public
             _categorieRepository = categorieRepository;
         }
 
-        public async Task<IEnumerable<CategorieDto>> GetAllActiveAsync()
+        public async Task<ServiceResult<IEnumerable<CategorieDto>>> GetAllActiveAsync()
         {
             var categories = await _categorieRepository.GetAllAsync();
 
-            // Hier könnte man eine Baumstruktur aufbauen, für den Anfang eine flache Liste
-            return categories
+            var activeCategories = categories
                 .Where(c => c.IsActive)
-                .Select(c => new CategorieDto
-                {
-                    Id = c.Id,
-                    Name = c.Name,
-                    Slug = c.Slug,
-                    Description = c.Description,
-                    ParentcategorieId = c.ParentcategorieId,
-                    ImageUrl = c.ImageUrl,
-                    IsActive = c.IsActive,
-                    DisplayOrder = c.DisplayOrder
-                }).ToList();
+                .Select(MapToDto)
+                .ToList();
+
+            return ServiceResult.Ok<IEnumerable<CategorieDto>>(activeCategories);
         }
 
-        public async Task<CategorieDto?> GetBySlugAsync(string slug)
+        public async Task<ServiceResult<CategorieDto>> GetBySlugAsync(string slug)
         {
             var categorie = await _categorieRepository.GetBySlugAsync(slug);
-            if (categorie == null || !categorie.IsActive) return null;
+            if (categorie == null || !categorie.IsActive)
+            {
+                return ServiceResult.Fail<CategorieDto>(ServiceResultType.NotFound, $"Kategorie mit dem Slug '{slug}' wurde nicht gefunden oder ist nicht aktiv.");
+            }
 
+            return ServiceResult.Ok(MapToDto(categorie));
+        }
+
+        private CategorieDto MapToDto(Categorie c)
+        {
             return new CategorieDto
             {
-                Id = categorie.Id,
-                Name = categorie.Name,
-                Slug = categorie.Slug,
-                Description = categorie.Description,
-                ParentcategorieId = categorie.ParentcategorieId,
-                ImageUrl = categorie.ImageUrl,
-                IsActive = categorie.IsActive,
-                DisplayOrder = categorie.DisplayOrder
+                Id = c.Id,
+                Name = c.Name,
+                Slug = c.Slug,
+                Description = c.Description,
+                ParentcategorieId = c.ParentcategorieId,
+                ImageUrl = c.ImageUrl,
+                IsActive = c.IsActive,
+                DisplayOrder = c.DisplayOrder
             };
         }
     }
diff --git a/Webshop.Application/Services/Public/Interfaces/ICategorieService.cs b/Webshop.Application/Services/Public/Interfaces/ICategorieService.cs
index b554fe4..448846b 100644
--- a/Webshop.Application/Services/Public/Interfaces/ICategorieService.cs
+++ b/Webshop.Application/Services/Public/Interfaces/ICategorieService.cs
@@ -1,13 +1,14 @@
 // src/Webshop.Application/Services/Public/Icategorieservice.cs
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using Webshop.Application;
 using Webshop.Application.DTOs.Categorie;
 
 namespace Webshop.Application.Services.Public
 {
     public interface ICategorieService
     {
-        Task<IEnumerable<CategorieDto>> GetAllActiveAsync();
-        Task<CategorieDto?> GetBySlugAsync(string slug);
+        Task<ServiceResult<IEnumerable<CategorieDto>>> GetAllActiveAsync();
+        Task<ServiceResult<CategorieDto>> GetBySlugAsync(string slug);
     }
 }
\ No newline at end of file