enh: __messages__ support for tools

backend/utils/misc.py

@@ -3,7 +3,7 @@ import hashlib
 import json
 import re
 from datetime import timedelta
-from typing import Optional, List
+from typing import Optional, List, Tuple
 
 
 def get_last_user_message(messages: List[dict]) -> str:
@@ -28,6 +28,21 @@ def get_last_assistant_message(messages: List[dict]) -> str:
     return None
 
 
+def get_system_message(messages: List[dict]) -> dict:
+    for message in messages:
+        if message["role"] == "system":
+            return message
+    return None
+
+
+def remove_system_message(messages: List[dict]) -> List[dict]:
+    return [message for message in messages if message["role"] != "system"]
+
+
+def pop_system_message(messages: List[dict]) -> Tuple[dict, List[dict]]:
+    return get_system_message(messages), remove_system_message(messages)
+
+
 def add_or_update_system_message(content: str, messages: List[dict]):
     """
     Adds a new system message at the beginning of the messages list