Update app.py

app.py

@@ -112,6 +112,10 @@ def remove_nested_think_tags_stack(text):
 
 def cleanMessages(messages: List[ChatMessage], removeThinkingContent: bool = False):
     promptStrList = []
+    # Safety check in case messages is None
+    if not messages:
+        return ""
+        
     for message in messages:
         content = message.content.strip()
         content = re.sub(r"\n+", "\n", content)
@@ -581,6 +585,14 @@ async def chat_completions(request: ChatCompletionRequest):
         if req_data.get(k) is None: req_data[k] = v
     realRequest = ChatCompletionRequest(**req_data)
 
+    # FIX: Handle missing messages (legacy completion API support)
+    if realRequest.messages is None:
+        if realRequest.prompt:
+            realRequest.messages = [ChatMessage(role="user", content=realRequest.prompt)]
+        else:
+            # Fallback to empty list to prevent crashes in prune_context/cleanMessages
+            realRequest.messages = []
+
     enable_tools = ":online" in raw_model or realRequest.tools is not None
     
     if enable_tools:
@@ -590,6 +602,8 @@ async def chat_completions(request: ChatCompletionRequest):
                  realRequest.messages[0].content += f"\n\n{ToolEngine.TOOL_SYSTEM_PROMPT}"
             else:
                 realRequest.messages.insert(0, sys_msg)
+        else:
+            realRequest.messages.append(sys_msg)
 
     realRequest.messages = prune_context(realRequest.messages, target_model, realRequest.max_tokens or 1024)