Update app.py

app.py

@@ -65,6 +65,39 @@ def _system_prompt_for(name: str) -> str:
     )
 
 
+def normalize_history(history):
+    """
+    Gradio may send messages where `content` is a list of rich parts:
+      {"role": "assistant",
+       "content": [{"type": "text", "text": "hello"}]}
+
+    We convert everything into:
+      {"role": ..., "content": "plain string"}
+    """
+    if history is None:
+        return []
+
+    norm = []
+    for msg in history:
+        role = msg.get("role", "user")
+        content = msg.get("content", "")
+
+        if isinstance(content, list):
+            # e.g. [{"type":"text","text":"..."}, ...]
+            parts = []
+            for part in content:
+                if isinstance(part, dict) and part.get("type") == "text":
+                    parts.append(part.get("text", ""))
+                else:
+                    parts.append(str(part))
+            content = "\n".join(parts)
+        else:
+            content = str(content)
+
+        norm.append({"role": role, "content": content})
+    return norm
+
+
 @spaces.GPU()
 def get_response(conversation):
     """
@@ -112,7 +145,7 @@ def get_response(conversation):
 def stream_chat(history, character_a, character_b):
     """
     history: list of messages (messages format):
-      [{"role": "user" | "assistant", "content": "..."}, ...]
+      [{"role": "user" | "assistant", "content": ...}, ...]
 
     In the UI:
       - user messages = Character B
@@ -122,8 +155,8 @@ def stream_chat(history, character_a, character_b):
       1. B says something new (as 'user')
       2. A replies (as 'assistant')
     """
-    if history is None:
-        history = []
+    # 🔑 Normalize history coming from Gradio into plain strings
+    history = normalize_history(history)
 
     # ---------- B speaks (user side) ----------
     if len(history) == 0:
@@ -133,7 +166,7 @@ def stream_chat(history, character_a, character_b):
             "Introduce yourself and start the conversation."
         )
     else:
-        # Find last assistant message (A) to respond to
+        # Last assistant message (A) to respond to
         last_msg = history[-1]
         last_text = last_msg["content"]
         b_user_prompt = (
@@ -233,7 +266,7 @@ with gr.Blocks() as demo:
         gr.Markdown(" ")
         image_b = gr.Image(show_label=False, interactive=False)
 
-    # IMPORTANT: no 'type=' argument here; your Gradio build doesn't support it
+    # No 'type' kwarg – your Gradio build doesn't support it, but it *does* use messages format
     chat = gr.Chatbot(show_label=False)
     submit_button = gr.Button("Start Conversation")