diff --git a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/models/user-management.api.models.ts b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/models/user-management.api.models.ts
index f056886..de94dc2 100644
--- a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/models/user-management.api.models.ts
+++ b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/models/user-management.api.models.ts
@@ -60,15 +60,15 @@ export interface GroupOfUser {
 
 export interface UserRep {
     id?: number,
+    repUserId?: number,
     userId: number,
     repGroupId?: number,
     groupId?: number,
     addedWho: string,
-    repUserId?: number,
+    repUser?: User
     user?: User,
     repGroup?: Group,
-    group?: Group,
-    repUser?: User
+    group?: Group,    
 }
 
 export interface DirGroup {
diff --git a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/environments/environment.prod.ts b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/environments/environment.prod.ts
index 68c3399..0f8d432 100644
--- a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/environments/environment.prod.ts
+++ b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/environments/environment.prod.ts
@@ -214,6 +214,10 @@ export const env = {
                 value: "yyyy-MM-dd",
                 name: "yyyy-MM-dd",
             }
+        ],
+        languages: [
+            { value: "de-DE", name: "de-DE" },
+            { value: "en-US", name: "en-US" }
         ]
     }
 };
diff --git a/DigitalData.UserManager.API/Controllers/AuthController.cs b/DigitalData.UserManager.API/Controllers/AuthController.cs
index 617b681..cfd43e6 100644
--- a/DigitalData.UserManager.API/Controllers/AuthController.cs
+++ b/DigitalData.UserManager.API/Controllers/AuthController.cs
@@ -21,15 +21,16 @@ namespace DigitalData.UserManager.API.Controllers
         private readonly IDirectorySearchService _dirSearchService;
         private readonly IStringLocalizer<Resource> _localizer;
         private readonly ILogger<AuthController> _logger;
-
-        public AuthController(IUserService userService, IGroupOfUserService gouService, IDirectorySearchService directorySearchService, IStringLocalizer<Resource> localizer, ILogger<AuthController> logger)
+        private readonly IConfiguration _config;
+        public AuthController(IUserService userService, IGroupOfUserService gouService, IDirectorySearchService directorySearchService, IStringLocalizer<Resource> localizer, ILogger<AuthController> logger, IConfiguration configuration)
         {
             _userService = userService;
             _gouService = gouService;
             _dirSearchService = directorySearchService;
             _localizer = localizer;
             _logger = logger;
-        }
+            _config = configuration;
+        }    
 
         [AllowAnonymous]
         [HttpGet("check")]
@@ -57,10 +58,13 @@ namespace DigitalData.UserManager.API.Controllers
                 if (!isValid)
                     return Unauthorized(Result.Fail().Message(_localizer[Key.UserNotFound]));
 
-                var gouMsg = await _gouService.HasGroup(login.Username, "PM_USER", caseSensitive: false);
+                var allowedGroupName = _config.GetSection("AllowedGroupName").Get<string>()
+                    ?? throw new InvalidOperationException("Allowed group names configuration is missing.");
+
+                var gouMsg = await _gouService.HasGroup(login.Username, allowedGroupName, caseSensitive: false);
                 if (!gouMsg.IsSuccess)
                     return Unauthorized(Result.Fail().Message(_localizer[Key.UnauthorizedUser]));
-
+                
                 //find the user
                 var uRes = await _userService.ReadByUsernameAsync(login.Username);
                 if (!uRes.IsSuccess || uRes.Data is null)
diff --git a/DigitalData.UserManager.API/Controllers/ConstantsController.cs b/DigitalData.UserManager.API/Controllers/ConstantsController.cs
deleted file mode 100644
index 645a595..0000000
--- a/DigitalData.UserManager.API/Controllers/ConstantsController.cs
+++ /dev/null
@@ -1,27 +0,0 @@
-using DigitalData.UserManager.API.Models;
-using Microsoft.AspNetCore.Mvc;
-using Microsoft.Extensions.Options;
-
-namespace DigitalData.UserManager.API.Controllers
-{
-    [Route("api/[controller]")]
-    [ApiController]
-    public class ConstantsController : ControllerBase
-    {
-        private readonly Constants _constants;
-        public ConstantsController(IOptions<Constants> constantsOptions)
-        {
-            _constants = constantsOptions.Value;
-        }
-
-        [HttpGet]
-        public IActionResult GetConstant(string? name = null)
-        {
-            if(name is null)
-                return Ok(_constants);
-
-
-            return Ok(_constants[name]);
-        }
-    }
-}
\ No newline at end of file
diff --git a/DigitalData.UserManager.API/DigitalData.UserManager.API.csproj b/DigitalData.UserManager.API/DigitalData.UserManager.API.csproj
index 79a0e4c..4920854 100644
--- a/DigitalData.UserManager.API/DigitalData.UserManager.API.csproj
+++ b/DigitalData.UserManager.API/DigitalData.UserManager.API.csproj
@@ -61,6 +61,7 @@
 
   <ItemGroup>
     <Folder Include="ClientApp\" />
+    <Folder Include="Models\" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/DigitalData.UserManager.API/Models/Constants.cs b/DigitalData.UserManager.API/Models/Constants.cs
deleted file mode 100644
index 66656db..0000000
--- a/DigitalData.UserManager.API/Models/Constants.cs
+++ /dev/null
@@ -1,13 +0,0 @@
-using System.Reflection;
-
-namespace DigitalData.UserManager.API.Models
-{
-    public class Constants
-    {
-        public IEnumerable<string> UserLanguages { get; init; } = Array.Empty<string>();
-
-        public object? this[string propertyName] => GetType()
-            .GetProperty(propertyName, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance)?
-            .GetValue(this, null);
-    }
-}
\ No newline at end of file
diff --git a/DigitalData.UserManager.API/Program.cs b/DigitalData.UserManager.API/Program.cs
index 8b6a88e..61ead86 100644
--- a/DigitalData.UserManager.API/Program.cs
+++ b/DigitalData.UserManager.API/Program.cs
@@ -9,8 +9,6 @@ using DigitalData.Core.API;
 using DigitalData.UserManager.API.Controllers;
 using DigitalData.UserManager.Application.Services;
 using Microsoft.Data.SqlClient;
-using System.Reflection.Metadata;
-using DigitalData.UserManager.API.Models;
 
 var logger = LogManager.Setup().LoadConfigurationFromAppSettings().GetCurrentClassLogger();
 logger.Debug("init main");
@@ -80,8 +78,6 @@ try {
 
     builder.Services.AddCookieBasedLocalizer();
 
-    builder.ConfigureBySection<Constants>();
-
     var app = builder.Build();
 
     cnn_str = new(() =>
diff --git a/DigitalData.UserManager.API/appsettings.json b/DigitalData.UserManager.API/appsettings.json
index 4c1f4c9..8820afc 100644
--- a/DigitalData.UserManager.API/appsettings.json
+++ b/DigitalData.UserManager.API/appsettings.json
@@ -71,13 +71,8 @@
     "Key": "JGPwHVD0BQmC7upi5OV11PzzIk47ugTJoqBV/et5w40=",
     "IV": "gMuetIjlPvJnSzu+i7I3xg=="
   },
+  "AllowedGroupName": "UM_ADMINS",
   // Delete below in production
   "UseEncryptor": true,
-  "UseSwagger": true,
-  "Constants": {
-    "UserLanguages": [
-      "de-DE",
-      "en-US"
-    ]
-  }
+  "UseSwagger": true
 }
\ No newline at end of file
diff --git a/DigitalData.UserManager.Application/DTOs/Base/BaseReadDto.cs b/DigitalData.UserManager.Application/DTOs/Base/BaseReadDto.cs
index 1a37358..3265439 100644
--- a/DigitalData.UserManager.Application/DTOs/Base/BaseReadDto.cs
+++ b/DigitalData.UserManager.Application/DTOs/Base/BaseReadDto.cs
@@ -2,5 +2,6 @@
 
 namespace DigitalData.UserManager.Application.DTOs.Base
 {
+    // TODO: use getter - setter methods for a simple inheritance.
     public record BaseReadDto(int Id, string? AddedWho, DateTime? AddedWhen, string? ChangedWho, DateTime? ChangedWhen) : BaseDTO<int>(Id);
 }
\ No newline at end of file
diff --git a/DigitalData.UserManager.Application/DTOs/User/UserReadDto.cs b/DigitalData.UserManager.Application/DTOs/User/UserReadDto.cs
index fbfef1b..eac5982 100644
--- a/DigitalData.UserManager.Application/DTOs/User/UserReadDto.cs
+++ b/DigitalData.UserManager.Application/DTOs/User/UserReadDto.cs
@@ -4,6 +4,7 @@ using DigitalData.EmailProfilerDispatcher.Abstraction.Attributes;
 
 namespace DigitalData.UserManager.Application.DTOs.User
 {
+    //TODO: inherit from base read dto
     public record UserReadDto()
     {
 		public int Id { get; set; }