2 files changed, 31 insertions, 0 deletions
diff --git a/BackEnd/Timeline/Models/Http/ErrorResponse.cs b/BackEnd/Timeline/Models/Http/ErrorResponse.cs
new file mode 100644
index 00000000..119e3977
--- /dev/null
+++ b/BackEnd/Timeline/Models/Http/ErrorResponse.cs
@@ -0,0 +1,19 @@
+namespace Timeline.Models.Http
+{
+    public class ErrorResponse
+    {
+        public const string InvalidRequest = "INVALID_REQUEST";
+        public const string EntityExist = "ENTITY_EXIST";
+        public const string InvalidOperation = "INVALID_OPERATION";
+
+        public ErrorResponse(string error, string message)
+        {
+            Error = error;
+            Message = message;
+        }
+
+        public string Error { get; set; }
+
+        public string Message { get; set; }
+    }
+}
diff --git a/BackEnd/Timeline/Models/Validation/PositiveIntegerAttribute.cs b/BackEnd/Timeline/Models/Validation/PositiveIntegerAttribute.cs
new file mode 100644
index 00000000..78e2f0b4
--- /dev/null
+++ b/BackEnd/Timeline/Models/Validation/PositiveIntegerAttribute.cs
@@ -0,0 +1,12 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Timeline.Models.Validation
+{
+    public class PositiveIntegerAttribute : RangeAttribute
+    {
+        public PositiveIntegerAttribute() : base(1, int.MaxValue)
+        {
+        }
+    }
+}
+