diff --git a/haystack/database/base.py b/haystack/database/base.py
new file mode 100644
index 000000000..5a5ada63c
--- /dev/null
+++ b/haystack/database/base.py
@@ -0,0 +1,21 @@
+from abc import abstractmethod
+
+
+class BaseDocumentStore:
+    """
+    Base class for implementing DataStores.
+    """
+
+    @abstractmethod
+    def write_documents(self, documents):
+        pass
+
+    @abstractmethod
+    def get_document_by_id(self, id):
+        pass
+
+    @abstractmethod
+    def get_document_ids_by_tag(self, tag):
+        pass
+
+