Update app.py

app.py

@@ -178,11 +178,26 @@ def build_answer(query: str) -> str:
     return intro + "\n".join(bullets) + guidance
 
 
-def chat_respond(message: str, history: List[Tuple[str, str]]):
-    """Gradio ChatInterface-compatible respond function."""
+def chat_respond(message: str, history):
     answer = build_answer(message)
-    history = history + [(message, answer)]
-    return answer, history
+
+    # Convert Gradio history (list of dicts) OR tuples into safe message list
+    cleaned_history = []
+
+    if isinstance(history, list):
+        for m in history:
+            if isinstance(m, dict):  # already the new format
+                cleaned_history.append(m)
+            elif isinstance(m, tuple) and len(m) == 2:
+                cleaned_history.append({"role": "user", "content": m[0]})
+                cleaned_history.append({"role": "assistant", "content": m[1]})
+
+    # Append new messages
+    cleaned_history.append({"role": "user", "content": message})
+    cleaned_history.append({"role": "assistant", "content": answer})
+
+    # ChatInterface expects just the answer, NOT a tuple for the reply
+    return answer, cleaned_history
 
 
 # -----------------------------
@@ -201,7 +216,7 @@ chat = gr.ChatInterface(
     fn=chat_respond,
     title="Self-Service KB Assistant",
     description=description,
-    chatbot=gr.Chatbot(height=420, show_copy_button=True),
+    chatbot=gr.Chatbot(height=420, show_copy_button=True, type="messages"),
     examples=[
         "What makes a good knowledge base article?",
         "How could a KB assistant help agents?",