diff --git a/src/yard/api.py b/src/yard/api.py
index 241207f..b66cd6c 100644
--- a/src/yard/api.py
+++ b/src/yard/api.py
@@ -48,13 +48,10 @@ def build_collection_pattern():
             path = r'%s%s/?$' %(self.__path, resource_path)
             return build_pattern(path, self.__collection_routes, name)
 
-        self.__urlpatterns.append( single_pattern() )
-        self.__urlpatterns.append( collection_pattern() )
-            
-        #if has_any( resource_class, self.__single_routes ):
-        #    self.__urlpatterns.append( build_single_pattern() )
-        #if has_any( resource_class, self.__collection_routes ):
-        #    self.__urlpatterns.append( build_collection_pattern() )
+        if has_any( resource_class, self.__single_routes ):
+            self.__urlpatterns.append( build_single_pattern() )
+        if has_any( resource_class, self.__collection_routes ):
+            self.__urlpatterns.append( build_collection_pattern() )
         if hasattr(resource_class, 'model'):
             self.__mapping[ resource_class.model ] = resource_class
 
diff --git a/src/yard/resources/__init__.py b/src/yard/resources/__init__.py
index 3480f97..d7d9017 100644
--- a/src/yard/resources/__init__.py
+++ b/src/yard/resources/__init__.py
@@ -24,7 +24,7 @@ class Meta(object):
     class Pagination(object):
         pass
     
-    def __init__(self, api, routes):
+    def __init__(self, api, routes):        
         self._api         = api
         self.__routes     = routes # maps http methods with respective views
         self.__meta       = ResourceMeta( self.Meta )
@@ -33,15 +33,23 @@ def __init__(self, api, routes):
         self.fields       = self.__get_fields()
         self.index_fields = getattr(self, "index_fields", self.fields)
         self.show_fields  = getattr(self, "show_fields", self.fields)
-        self.description = getattr(self, "description", "not provided")
+        self.description  = getattr(self, "description", "not provided")
+        self.__allowed_methods = [k for k,v in self.__routes.items() if hasattr(self, v)]
+        self.__builders = self.__create_json_builders()
         self.__meta.page_class = self.__pagination #TEMPORARY
-
+    
     def __get_fields(self):
         if hasattr(self, "fields"):
             return self.fields
         elif not hasattr(self, "model"):
             return {}
         return model_to_fields(self.model)
+        
+    def __create_json_builders(self):
+        return {
+            id(i): JSONbuilder(self._api, i) 
+            for i in [self.index_fields, self.show_fields, self.fields] if not callable(i)
+        }
     
     def __call__(self, request, **parameters):
         '''
@@ -77,12 +85,12 @@ def __resource_parameters(self, request, parameters):
             for i in self.__parameters.get( request ):
                 resource_params.update( i )
         return resource_params
-
+    
     def __get_builder(self, fields, parameters):
         if callable(fields):
             current_fields = fields(parameters)
             return JSONbuilder( self._api, current_fields ), current_fields
-        return JSONbuilder( self._api, fields ), fields
+        return self.__builders[ id(fields) ], fields
 
     def __handle_response(self, request, response, current_fields, resource_parameters, builder):
         '''
@@ -146,7 +154,7 @@ def __serialize_all(self, resources, builder):
         return [builder.to_json(i) for i in resources]
 
     def serialize_all(self, resources, fields):
-        builder = JSONbuilder( self._api, fields )
+        builder = self.__builders.get( id(fields) ) or JSONbuilder(self._api, fields)
         return self.__serialize_all( resources, builder )
 
     def __serialize(self, resource, builder):
@@ -156,7 +164,7 @@ def __serialize(self, resource, builder):
         return builder.to_json(resource)
 
     def serialize(self, resource, fields):
-        builder = JSONbuilder( self._api, fields )
+        builder = self.__builders.get( id(fields) ) or JSONbuilder(self._api, fields)
         return self.__serialize( resource, builder )
          
     #
@@ -199,8 +207,8 @@ def handle_options(self, request, parameters):
         response = self.options(request, **parameters)
         builder, fields = self.__get_builder(self.fields, parameters)
         response = self.__handle_response(request, response, fields, parameters, builder)
-        response['Allow'] = ','.join([k for k,v in self.__routes.items() if hasattr(self, v)])
+        response['Allow'] = self.__allowed_methods
         return response
-        
+    
     def options(self, request, **parameters):
-        return 200
+        return 404 if len(self.__allowed_methods) <= 1 else 200