Fix: handle streaming response format correctly

app.py

@@ -6,24 +6,9 @@ import gradio as gr
 from huggingface_hub import InferenceClient
 
 HF_TOKEN = os.environ.get("HF_TOKEN")
+client = InferenceClient(token=HF_TOKEN)
 
-# Try multiple providers in order of preference
-def get_client():
-    models = [
-        "Qwen/Qwen2.5-72B-Instruct",
-        "Qwen/Qwen2.5-7B-Instruct",
-        "meta-llama/Llama-3.1-8B-Instruct",
-    ]
-    for model in models:
-        try:
-            c = InferenceClient(model, token=HF_TOKEN)
-            # Quick test
-            return c, model
-        except Exception:
-            continue
-    return InferenceClient(models[0], token=HF_TOKEN), models[0]
-
-client, MODEL_USED = get_client()
+MODEL = "Qwen/Qwen2.5-72B-Instruct"
 
 SYSTEM_PROMPT = """You are DeepMed-R1, a medical reasoning AI trained with GRPO and multi-objective clinical rewards on AMD MI300X.
 
@@ -57,24 +42,30 @@ def respond(message, history):
 
     response = ""
     try:
-        for token in client.chat_completion(messages=messages, max_tokens=3000, temperature=0.3, top_p=0.95, stream=True):
-            delta = token.choices[0].delta.content or ""
-            response += delta
-            yield response
+        stream = client.chat_completion(
+            model=MODEL,
+            messages=messages,
+            max_tokens=3000,
+            temperature=0.3,
+            top_p=0.95,
+            stream=True,
+        )
+        for chunk in stream:
+            if chunk.choices and len(chunk.choices) > 0:
+                delta = chunk.choices[0].delta
+                if hasattr(delta, "content") and delta.content:
+                    response += delta.content
+                    yield response
     except Exception as e:
         error_msg = str(e)
-        if "api_key" in error_msg.lower() or "token" in error_msg.lower() or "401" in error_msg:
-            yield ("⚠️ **Authentication Required**\n\n"
-                   "Please add your HF_TOKEN as a Space secret:\n"
-                   "1. Go to Space Settings → Repository secrets\n"
-                   "2. Add secret: Name=`HF_TOKEN`, Value=your token\n\n"
-                   f"Error: {error_msg}")
+        if not response:
+            yield f"⚠️ Error: {error_msg}\n\nPlease ensure HF_TOKEN is set in Space secrets."
         else:
-            yield f"Error: {error_msg}\n\nPlease try again."
+            yield response
 
 
 with gr.Blocks(title="DeepMed-R1", theme=gr.themes.Soft(primary_hue="blue")) as demo:
-    gr.Markdown(f"""
+    gr.Markdown("""
 # 🏥 DeepMed-R1: Medical Reasoning AI
 
 **Systematic clinical reasoning powered by GRPO + Multi-Objective Clinical Rewards**