diff --git a/juju/delta.py b/juju/delta.py
new file mode 100644
index 0000000..b1eba23
--- /dev/null
+++ b/juju/delta.py
@@ -0,0 +1,79 @@
+from .client import client
+
+
+def get_entity_delta(d):
+    return _delta_types[d.entity](d.deltas)
+
+
+def get_entity_class(entity_type):
+    return _delta_types[entity_type].get_entity_class()
+
+
+class EntityDelta(client.Delta):
+    def get_id(self):
+        return self.data['id']
+
+    @classmethod
+    def get_entity_class(self):
+        return None
+
+
+class ActionDelta(EntityDelta):
+    @classmethod
+    def get_entity_class(self):
+        from .action import Action
+        return Action
+
+
+class ApplicationDelta(EntityDelta):
+    def get_id(self):
+        return self.data['name']
+
+    @classmethod
+    def get_entity_class(self):
+        from .application import Application
+        return Application
+
+
+class AnnotationDelta(EntityDelta):
+    def get_id(self):
+        return self.data['tag']
+
+    @classmethod
+    def get_entity_class(self):
+        from .annotation import Annotation
+        return Annotation
+
+
+class MachineDelta(EntityDelta):
+    @classmethod
+    def get_entity_class(self):
+        from .machine import Machine
+        return Machine
+
+
+class UnitDelta(EntityDelta):
+    def get_id(self):
+        return self.data['name']
+
+    @classmethod
+    def get_entity_class(self):
+        from .unit import Unit
+        return Unit
+
+
+class RelationDelta(EntityDelta):
+    @classmethod
+    def get_entity_class(self):
+        from .relation import Relation
+        return Relation
+
+
+_delta_types = {
+    'action': ActionDelta,
+    'application': ApplicationDelta,
+    'annotation': AnnotationDelta,
+    'machine': MachineDelta,
+    'unit': UnitDelta,
+    'relation': RelationDelta,
+}