fix: Remove created_at field from messages

agents-api/agents_api/routers/sessions/chat.py

@@ -1,3 +1,4 @@
+from contextlib import suppress
 from typing import Annotated
 from uuid import UUID, uuid4
 
@@ -51,7 +52,7 @@ async def chat(
     settings: dict = chat_context.settings.model_dump()
     env: dict = chat_context.get_chat_environment()
     settings["model"] = f"openai/{settings['model']}"  # litellm proxy idiosyncracy
-    
+
     # Render the messages
     new_raw_messages = [msg.model_dump() for msg in chat_input.messages]
 
@@ -64,6 +65,11 @@ async def chat(
 
     env["docs"] = doc_references
     new_messages = await render_template(new_raw_messages, variables=env)
+
+    for m in past_messages:
+        with suppress(KeyError):
+            del m["created_at"]
+
     messages = past_messages + new_messages
 
     # Get the tools