diff --git a/letta/groups/helpers.py b/letta/groups/helpers.py
index 3b7f70d0..ea1503d7 100644
--- a/letta/groups/helpers.py
+++ b/letta/groups/helpers.py
@@ -87,6 +87,7 @@ def load_multi_agent(
 
 def stringify_message(message: Message, use_assistant_name: bool = False) -> str | None:
     assistant_name = message.name or "assistant" if use_assistant_name else "assistant"
+
     if message.role == "user":
         try:
             messages = []
@@ -97,7 +98,9 @@ def stringify_message(message: Message, use_assistant_name: bool = False) -> str
                     messages.append(f"{message.name or 'user'}: [Image Here]")
             return "\n".join(messages)
         except:
-            return f"{message.name or 'user'}: {message.content[0].text}"
+            if message.content and len(message.content) > 0:
+                return f"{message.name or 'user'}: {message.content[0].text}"
+            return None
     elif message.role == "assistant":
         messages = []
         if message.content:
@@ -105,13 +108,42 @@ def stringify_message(message: Message, use_assistant_name: bool = False) -> str
                 if isinstance(content, TextContent):
                     messages.append(f"{assistant_name}: {content.text}")
                 elif isinstance(content, ReasoningContent):
-                    messages.append(f"{assistant_name}: *thinking* {content.reasoning}")
+                    messages.append(f"{assistant_name}: <thinking>{content.reasoning}</thinking>")
         if message.tool_calls:
-            if message.tool_calls[0].function.name == "send_message":
-                messages.append(f"{assistant_name}: {json.loads(message.tool_calls[0].function.arguments)['message']}")
-            else:
-                messages.append(f"{assistant_name}: Calling tool {message.tool_calls[0].function.name}")
-        return "\n".join(messages)
+            for tool_call in message.tool_calls:
+                if tool_call.function.name == "send_message":
+                    messages.append(f"{assistant_name}: {json.loads(tool_call.function.arguments)['message']}")
+                else:
+                    messages.append(f"{assistant_name}: Calling tool {tool_call.function.name}")
+        return "\n".join(messages) if messages else None
+    elif message.role == "approval":
+        # role == "approval" has two cases:
+        # 1. Approval REQUEST: has tool_calls (assistant calling tool that needs HITL)
+        # 2. Approval RESPONSE: no tool_calls, has approve field (user's decision)
+
+        # Check if this is an approval request (has tool_calls)
+        if hasattr(message, "tool_calls") and message.tool_calls:
+            # Treat like assistant message calling a tool
+            messages = []
+            if message.content:
+                for content in message.content:
+                    if isinstance(content, TextContent):
+                        messages.append(f"{assistant_name}: {content.text}")
+                    elif isinstance(content, ReasoningContent):
+                        messages.append(f"{assistant_name}: <thinking>{content.reasoning}</thinking>")
+            for tool_call in message.tool_calls:
+                if tool_call.function.name == "send_message":
+                    messages.append(f"{assistant_name}: {json.loads(tool_call.function.arguments)['message']}")
+                else:
+                    messages.append(f"{assistant_name}: Calling tool {tool_call.function.name}")
+            return "\n".join(messages) if messages else None
+        else:
+            # Approval response - user approved/rejected
+            if hasattr(message, "approve") and message.approve is not None:
+                status = "approved" if message.approve else "rejected"
+                reason = f": {message.denial_reason}" if hasattr(message, "denial_reason") and message.denial_reason else ""
+                return f"[User {status}{reason}]"
+            return None
     elif message.role == "tool":
         if message.content:
             content = json.loads(message.content[0].text)
@@ -121,4 +153,13 @@ def stringify_message(message: Message, use_assistant_name: bool = False) -> str
     elif message.role == "system":
         return None
     else:
-        return f"{message.name or 'user'}: {message.content[0].text}"
+        if message.content and len(message.content) > 0:
+            # Handle different content types
+            content_item = message.content[0]
+            if isinstance(content_item, TextContent):
+                return f"{message.name or 'user'}: {content_item.text}"
+            elif isinstance(content_item, ReasoningContent):
+                return f"{message.name or 'user'}: <thinking>{content_item.reasoning}</thinking>"
+            elif isinstance(content_item, ImageContent):
+                return f"{message.name or 'user'}: [Image Here]"
+        return None