diff --git a/BlueWest.Api/Context/CompanyDbContext.cs b/BlueWest.Api/Context/CompanyDbContext.cs
index d608411..d001a5c 100644
--- a/BlueWest.Api/Context/CompanyDbContext.cs
+++ b/BlueWest.Api/Context/CompanyDbContext.cs
@@ -18,8 +18,7 @@ namespace BlueWest.WebApi.EF
         [EfUpdateMethods(
             updateType: typeof(CompanyUpdate), 
             returnType: typeof(CompanyUnique),
-            keyPropertyMemberName: nameof(Company.Id), 
-            keyPropertyMemberType: typeof(int))
+            keyPropertyMemberName: nameof(Company.Id))
         ]
 
         /*[EFUpdateMethods(typeof(int), 
@@ -36,8 +35,8 @@ namespace BlueWest.WebApi.EF
         [EfUpdateMethods(
             updateType: typeof(IndustryUpdate), 
             returnType: typeof(IndustryUnique),
-            keyPropertyMemberName: nameof(Industry.Id), 
-            keyPropertyMemberType: typeof(int))
+            keyPropertyMemberName: nameof(Industry.Id)
+            )
         ]
         
         public DbSet<Industry> Industries { get; set; }
diff --git a/BlueWest.Api/Context/CountryDbContext.cs b/BlueWest.Api/Context/CountryDbContext.cs
index cff8a29..f652ef7 100644
--- a/BlueWest.Api/Context/CountryDbContext.cs
+++ b/BlueWest.Api/Context/CountryDbContext.cs
@@ -16,6 +16,19 @@ namespace BlueWest.WebApi.EF
         /// <summary>
         /// Countries Database Table
         /// </summary>
+        
+        [EfGetOne(
+            returnType: typeof(CountryUnique), 
+            keyMembernameof: nameof(Country.Id))
+        ]
+        
+        [EfAddEntityToList(
+            listEntityType: typeof(Currency),  
+            listEntityCreateType: typeof(CurrencyCreate),
+            listEntityReturnType: typeof(CurrencyUnique), 
+            keyMembernameof: nameof(Country.Id))
+        ]
+        
         [EfAddMethods(
             createType: typeof(CountryCreate),
             returnType: typeof(CountryUnique))
@@ -24,9 +37,9 @@ namespace BlueWest.WebApi.EF
         [EfUpdateMethods(
             updateType: typeof(CountryUpdate), 
             returnType: typeof(CountryUnique),
-            keyPropertyMemberName: nameof(Country.Id), 
-            keyPropertyMemberType: typeof(int))
+            keyPropertyMemberName: nameof(Country.Id))
         ]
+        
         public DbSet<Country> Countries { get; set; }
     
         /// <summary>
@@ -38,8 +51,7 @@ namespace BlueWest.WebApi.EF
         [EfUpdateMethods(
             updateType: typeof(CurrencyUpdate), 
             returnType: typeof(CurrencyUnique),
-            keyPropertyMemberName: nameof(Currency.Id), 
-            keyPropertyMemberType: typeof(int))
+            keyPropertyMemberName: nameof(Currency.Id))
         ]
         public DbSet<Currency> Currencies { get; set; }
         
diff --git a/BlueWest.Api/Context/Extensions/EfAddEntityToListAttribute.cs b/BlueWest.Api/Context/Extensions/EfAddEntityToListAttribute.cs
new file mode 100644
index 0000000..bbded21
--- /dev/null
+++ b/BlueWest.Api/Context/Extensions/EfAddEntityToListAttribute.cs
@@ -0,0 +1,9 @@
+using System;
+
+namespace BlueWest.WebApi.EF;
+
+[AttributeUsage(AttributeTargets.Property)]
+public class EfAddEntityToListAttribute : Attribute
+{
+    public EfAddEntityToListAttribute(Type listEntityType,  Type listEntityCreateType, Type listEntityReturnType, string keyMembernameof) { }
+}
\ No newline at end of file
diff --git a/BlueWest.Api/Context/Extensions/EfGetManyAttribute.cs b/BlueWest.Api/Context/Extensions/EfGetManyAttribute.cs
index f3d878f..711fa26 100644
--- a/BlueWest.Api/Context/Extensions/EfGetManyAttribute.cs
+++ b/BlueWest.Api/Context/Extensions/EfGetManyAttribute.cs
@@ -1,6 +1,12 @@
+using System;
+
 namespace BlueWest.WebApi.EF;
 
-public class EfGetManyAttribute
+[AttributeUsage(AttributeTargets.Property)]
+public class EfGetManyAttribute : Attribute
 {
-    
+    public EfGetManyAttribute(Type returnType, string keyMemberName)
+    {
+        
+    }
 }
\ No newline at end of file
diff --git a/BlueWest.Api/Context/Extensions/EfGetOneAttribute.cs b/BlueWest.Api/Context/Extensions/EfGetOneAttribute.cs
index 6873f90..86a81cf 100644
--- a/BlueWest.Api/Context/Extensions/EfGetOneAttribute.cs
+++ b/BlueWest.Api/Context/Extensions/EfGetOneAttribute.cs
@@ -1,6 +1,12 @@
+using System;
+
 namespace BlueWest.WebApi.EF;
 
-public class EfGetOneAttribute
+[AttributeUsage(AttributeTargets.Property)]
+public sealed class EfGetOneAttribute : Attribute
 {
-    
+    public EfGetOneAttribute(Type returnType, string keyMembernameof)
+    {
+        
+    }
 }
\ No newline at end of file
diff --git a/BlueWest.Api/Context/Templates/AddToEntityTemplate.csx b/BlueWest.Api/Context/Templates/AddToEntityTemplate.csx
index 493a3fb..b3f3d82 100644
--- a/BlueWest.Api/Context/Templates/AddToEntityTemplate.csx
+++ b/BlueWest.Api/Context/Templates/AddToEntityTemplate.csx
@@ -1,8 +1,14 @@
+/// <summary>
+/// Adds a new {entityTypeName} to <see cref="{contextFullName}"></see> DbSet.
+/// </summary>
+/// <param name="dbContext">The database context.</param>
+/// <param name="{toCreateVarName}">The data type with the add data to create {entityTypeName}</param>
+/// <returns>The added data.</returns>
 
-public static (bool, {returnTypeFullName}) Add{entityTypeName}(
-this {contextFullName} dbContext, {createTypeFullName} {toCreateVarName}) {
-      var {newEntityVarName} = new {entityTypeFullName}({toCreateVarName});
-      dbContext.{propertyName}.Add({newEntityVarName});  
-      var success = dbContext.SaveChanges() >= 0;
-      return (success, new {returnTypeFullName}({newEntityVarName}));
+public static (bool, {returnTypeFullName}) Add{entityTypeName}(this {contextFullName} dbContext, {createTypeFullName} {toCreateVarName}) 
+{
+    var {newEntityVarName} = new {entityTypeFullName}({toCreateVarName});
+    dbContext.{propertyName}.Add({newEntityVarName});  
+    var success = dbContext.SaveChanges() >= 0;
+    return (success, new {returnTypeFullName}({newEntityVarName}));
 } 
diff --git a/BlueWest.Api/Context/Templates/AddToListInEntity.csx b/BlueWest.Api/Context/Templates/AddToListInEntity.csx
index e69de29..6d294f0 100644
--- a/BlueWest.Api/Context/Templates/AddToListInEntity.csx
+++ b/BlueWest.Api/Context/Templates/AddToListInEntity.csx
@@ -0,0 +1,26 @@
+public static (bool, string, {returnTypeFullName}) Add{listEntityTypeName}To{entityTypeName}(  this {contextFullName} dbContext, 
+            {keyTypeFullName} {keyVarName}, {listEntityCreateFullName} {listItemCreateVarName},   Expression<Func<{entityTypeFullName},bool>>[] duplicationValidations)
+{
+    var entityQuery = from aEntity in dbContext.{propertyName}
+        where aEntity.{keyVarName} == {keyVarName}
+        let itemsInList = aEntity.{entityListMemberName}
+        select aEntity;
+    
+    var entity = entityQuery.FirstOrDefault();
+    
+    if (entity == null) return (false, $"{nameof(country)} Not found.", null);
+    
+    foreach (var duplicationValidation in duplicationValidations)
+    {
+        var entityToGet = dbContext.{entityListMemberName}.FirstOrDefault(duplicationValidation);
+        if (entityToGet != null)
+        {
+            return (false, $"Duplication Validation failed: {nameof(duplicationValidation.Body.ToString)}", null);
+        }
+    }
+
+    var newListItem = new {listEntityFullName}({listItemCreateVarName});
+    entity.{entityListMemberName}.Add({listItemCreateVarName});
+    var success = dbContext.SaveChanges() >= 0;
+    return !success ? (false, "Error saving changes.", null) : (true, string.Empty, new {returnTypeFullName}(newListItem));
+}
\ No newline at end of file
diff --git a/BlueWest.Api/Context/Templates/UpdateEntityTemplate.csx b/BlueWest.Api/Context/Templates/UpdateEntityTemplate.csx
index 33147a4..9433679 100644
--- a/BlueWest.Api/Context/Templates/UpdateEntityTemplate.csx
+++ b/BlueWest.Api/Context/Templates/UpdateEntityTemplate.csx
@@ -1,13 +1,15 @@
-public static (bool, {returnTypeFullName}) Update{entityTypeName}(
-            this {contextFullName} dbContext, 
-            {updateTypeFullName} {updateVarName},
-            {keyTypeFullName} {keyVarName})
-        {
-            var {existingEntityVarName} = dbContext.{propertyName}.FirstOrDefault(x => x.{keyPropertyName} == {keyVarName});
-            if ({existingEntityVarName} == null) return (false, null);
-            {existingEntityVarName}.Update({updateVarName});
-            dbContext.{propertyName}.Update({existingEntityVarName});
-            var result = dbContext.SaveChanges() >= 0;
-            return (result, new {returnTypeFullName}({existingEntityVarName}));
-
-        }
\ No newline at end of file
+/// <summary>
+/// Updates {entityTypeName} in the DbSet of <see cref="{contextFullName}"></see>.
+/// </summary>
+/// <param name="dbContext">Database context</param>
+/// <param name="{updateVarName}">The data type with the add data to update {entityTypeName}</param>
+/// <returns>Returns the current data.</returns>
+public static (bool, {returnTypeFullName}) Update{entityTypeName}( this {contextFullName} dbContext, {updateTypeFullName} {updateVarName}, {keyTypeFullName} {keyVarName})
+{
+    var {existingEntityVarName} = dbContext.{propertyName}.FirstOrDefault(x => x.{keyPropertyName} == {keyVarName});
+    if ({existingEntityVarName} == null) return (false, null);
+    {existingEntityVarName}.Update({updateVarName});
+    dbContext.{propertyName}.Update({existingEntityVarName});
+    var result = dbContext.SaveChanges() >= 0;
+    return (result, new {returnTypeFullName}({existingEntityVarName}));
+}
\ No newline at end of file
diff --git a/BlueWest.Api/Controllers/CurrencyController.cs b/BlueWest.Api/Controllers/CurrencyController.cs
index 41b8b6d..a7a5530 100644
--- a/BlueWest.Api/Controllers/CurrencyController.cs
+++ b/BlueWest.Api/Controllers/CurrencyController.cs
@@ -77,17 +77,15 @@ namespace BlueWest.WebApi.Controllers
         [HttpPost]
         public ActionResult AddCurrency(CurrencyCreate currencyToCreate)
         {
-            /*var (success, newCurrency) = _dbContext.AddCurrency(currencyToCreate);
+            var (success, newCurrency) = _dbContext.AddCurrency(currencyToCreate);
 
             if (!success)
             {
                 return new NotFoundResult();
             }
 
-            return CreatedAtRoute(nameof(GetCurrencyById), new {CurrencyId = newCurrency.Code},
-                new CurrencyUnique(newCurrency));*/
+            return CreatedAtRoute(nameof(GetCurrencyById), new {CurrencyId = newCurrency.Code}, newCurrency);
 
-            return null;
         }
 
         /// <summary>