fix: openai illegal char in name check (#1971)

letta/schemas/message.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import copy
 import json
+import re
 import uuid
 import warnings
 from collections import OrderedDict
@@ -700,9 +701,12 @@ class Message(BaseMessage):
         else:
             raise ValueError(self.role)
 
-        # Optional field, do not include if null
+        # Optional field, do not include if null or invalid
         if self.name is not None:
-            openai_message["name"] = self.name
+            if bool(re.match(r"^[^\s<|\\/>]+$", self.name)):
+                warnings.warn(f"Using OpenAI with invalid 'name' field (name={self.name} role={self.role}).")
+            else:
+                openai_message["name"] = self.name
 
         if parse_content_parts:
             for content in self.content: