diff --git a/Yavsc/Models/Workflow/Activity.cs b/Yavsc/Models/Workflow/Activity.cs
index 8105002f..537b8dc2 100644
--- a/Yavsc/Models/Workflow/Activity.cs
+++ b/Yavsc/Models/Workflow/Activity.cs
@@ -4,48 +4,50 @@ using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 using Newtonsoft.Json;
-using Yavsc.Models.Market;
 
 namespace Yavsc.Models.Workflow
 {
-    public class Activity : IBaseTrackedEntity
+    using Market;
+    using YavscLib;
+
+    public class Activity : IBaseTrackedEntity, IActivity
     {
 
-        [StringLength(512),Required,Key]
-        public string Code {get; set;}
+        [StringLength(512), Required, Key]
+        public string Code { get; set; }
         /// <summary>
         ///
         /// </summary>
         /// <returns></returns>
-        [StringLength(512),Required()]
-        public string Name {get; set;}
+        [StringLength(512), Required()]
+        public string Name { get; set; }
 
         [StringLength(512)]
         public string ParentCode { get; set; }
 
-        [ForeignKey("ParentCode"),JsonIgnore]
+        [ForeignKey("ParentCode"), JsonIgnore]
         public virtual Activity Parent { get; set; }
 
-        [InverseProperty("Parent"),JsonIgnore]
+        [InverseProperty("Parent"), JsonIgnore]
         public virtual List<Activity> Children { get; set; }
 
-        public string Description {get; set;}
+        public string Description { get; set; }
         /// <summary>
         /// Name to associate to a performer in this activity domain
         /// </summary>
-        /// <returns></returns>
-        public string ActorDenomination {get; set;}
+        [Obsolete]
+        public string ActorDenomination { get; set; }
 
-        public string Photo {get; set;}
+        public string Photo { get; set; }
 
-       [InverseProperty("Context")]
+        [InverseProperty("Context")]
         public List<Service> Services { get; set; }
-        
+
         /// <summary>
         /// Moderation settings
         /// </summary>
         /// <returns></returns>
-        string ModeratorGroupName { get; set; }
+        public string ModeratorGroupName { get; set; }
 
         /// <summary>
         /// indice de recherche de cette activité
@@ -53,32 +55,32 @@ namespace Yavsc.Models.Workflow
         /// Valide entre 0 et 100,
         /// Il démarre à 0.
         /// </summary>
-        [Range(0,100)]
-        public int Rate { get; set; }
-        [DisplayAttribute(Name="SettingsClass")]
-        public string SettingsClassName { get; set; }
+        [Range(0, 100)]
+        public int Rate { get; set; }
+        [DisplayAttribute(Name = "SettingsClass")]
+        public string SettingsClassName { get; set; }
 
         [InverseProperty("Context")]
         public virtual List<CommandForm> Forms { get; set; }
 
         public DateTime DateCreated
         {
-            get; set; 
+            get; set;
         }
 
         public string UserCreated
         {
-            get; set; 
+            get; set;
         }
 
         public DateTime DateModified
         {
-            get; set; 
+            get; set;
         }
 
         public string UserModified
         {
-            get; set; 
+            get; set;
         }
     }
 }
diff --git a/Yavsc/Models/Workflow/CoWorking.cs b/Yavsc/Models/Workflow/CoWorking.cs
index 880b465a..f07954a4 100644
--- a/Yavsc/Models/Workflow/CoWorking.cs
+++ b/Yavsc/Models/Workflow/CoWorking.cs
@@ -3,7 +3,9 @@ using System.ComponentModel.DataAnnotations.Schema;
 
 namespace Yavsc.Models.Workflow
 {
-    public class CoWorking
+    using YavscLib;
+
+    public class CoWorking: ICoWorking
     {
         [Key(), DatabaseGenerated(DatabaseGeneratedOption.Identity)]
         public long Id {get; set; }
diff --git a/Yavsc/Models/Workflow/CommandForm.cs b/Yavsc/Models/Workflow/CommandForm.cs
index b8695da4..de9687d2 100644
--- a/Yavsc/Models/Workflow/CommandForm.cs
+++ b/Yavsc/Models/Workflow/CommandForm.cs
@@ -4,7 +4,8 @@ using Newtonsoft.Json;
 
 namespace Yavsc.Models.Workflow
 {
-    public class CommandForm 
+        using YavscLib;
+    public class CommandForm : ICommandForm
     {
         [Key,DatabaseGenerated(DatabaseGeneratedOption.Identity)]
         public long Id { get; set; }
diff --git a/YavscLib/IActivity.cs b/YavscLib/IActivity.cs
new file mode 100644
index 00000000..e9a9da8d
--- /dev/null
+++ b/YavscLib/IActivity.cs
@@ -0,0 +1,35 @@
+using System;
+
+namespace YavscLib
+{
+    public interface IActivity
+    {
+        string Code { get; set; }
+        string Name { get; set; }
+        string ParentCode { get; set; }
+        string Photo { get; set; }
+
+        string ModeratorGroupName { get; set; }
+        int Rate { get; set; }
+        string SettingsClassName { get; set; }
+        DateTime DateCreated
+        {
+            get; set;
+        }
+
+        string UserCreated
+        {
+            get; set;
+        }
+
+        DateTime DateModified
+        {
+            get; set;
+        }
+
+        string UserModified
+        {
+            get; set;
+        }
+    }
+}
\ No newline at end of file
diff --git a/YavscLib/ICoWorking.cs b/YavscLib/ICoWorking.cs
new file mode 100644
index 00000000..f9412664
--- /dev/null
+++ b/YavscLib/ICoWorking.cs
@@ -0,0 +1,10 @@
+namespace YavscLib
+{
+    public interface ICoWorking
+    {
+         long Id {get; set; }
+         string PerformerId { get; set; }
+         string WorkingForId { get; set; }
+         
+    }
+}
\ No newline at end of file
diff --git a/YavscLib/ICommandForm.cs b/YavscLib/ICommandForm.cs
new file mode 100644
index 00000000..3727edf2
--- /dev/null
+++ b/YavscLib/ICommandForm.cs
@@ -0,0 +1,11 @@
+namespace YavscLib
+{
+    public interface ICommandForm
+    {
+         long Id { get; set; }
+         string Action { get; set; }
+         string Title { get; set; } 
+         string ActivityCode { get; set; }
+         
+    }
+}
\ No newline at end of file