Update README.md

README.md

@@ -55,13 +55,19 @@ Please answer the following query:
 {{ query }}
 """.lstrip())
 
-def prepare_messages(query: str, tools: Optional[dict[str, any]] = None) -> list[dict[str, str]]:
+def prepare_messages(
+    query: str,
+    tools: Optional[dict[str, any]] = None,
+    conversation_history: Optional[list[dict[str, str]]] = None
+) -> list[dict[str, str]]:
     """Prepare the system and user messages for the given query and tools.
     
     Args:
         query: The query to be answered.
         tools: The tools available to the user. Defaults to None, in which case if a
             list without content will be passed to the model.
+        conversation_history: Exchange of messages, including the system_prompt from
+            the first query. Defaults to None, the first message in a conversation.
     """
     if tools is None:
         tools = []