Update app.py

app.py

@@ -76,10 +76,22 @@ def is_identity_query(message, history):
             return True
     return False
 
+def _iter_user_assistant(history):
+    """
+    Yield (user, assistant) pairs from a Gradio history list.
+    Safely handles items that are lists/tuples with >2 elements.
+    """
+    for item in (history or []):
+        if isinstance(item, (list, tuple)):
+            u = item[0] if len(item) > 0 else ""
+            a = item[1] if len(item) > 1 else ""
+            yield u, a
+        # If dicts ever appear, extend handling here.
+
 def _history_to_prompt(message, history):
     """Build a simple text prompt for the stable cohere.chat API."""
     parts = []
-    for u, a in (history or []):
+    for u, a in _iter_user_assistant(history):
         if u:
             parts.append(f"User: {u}")
         if a:
@@ -145,9 +157,11 @@ def load_local_model():
 
 def build_inputs(tokenizer, message, history):
     msgs = []
-    for u, a in (history or []):
-        msgs.append({"role": "user", "content": u})
-        msgs.append({"role": "assistant", "content": a})
+    for u, a in _iter_user_assistant(history):
+        if u:
+            msgs.append({"role": "user", "content": u})
+        if a:
+            msgs.append({"role": "assistant", "content": a})
     msgs.append({"role": "user", "content": message})
     return tokenizer.apply_chat_template(
         msgs, tokenize=True, add_generation_prompt=True, return_tensors="pt"