Update app.py

app.py

@@ -717,7 +717,7 @@ Provide a helpful, intelligent response using the real challenge data context.""
                             "Authorization": f"Bearer {self.openai_api_key}"  # FIXED: Proper auth header
                         },
                         json={
-                            "model": "o4-mini",  # Fast and cost-effective
+                            "model": "gpt-4o-mini",  # Fast and cost-effective
                             "messages": [
                                 {"role": "system", "content": "You are an expert Topcoder Challenge Intelligence Assistant with real MCP data access."},
                                 {"role": "user", "content": system_prompt}
@@ -1514,7 +1514,7 @@ def create_ultimate_interface():
                 # SECURE API INTEGRATION:
                 openai_api_key = os.getenv("OPENAI_API_KEY", "")
                 endpoint = "https://api.openai.com/v1/chat/completions"
-                model = "o4-mini"  # Fast and cost-effective
+                model = "gpt-4o-mini"  # Fast and cost-effective
                 context = "Real MCP challenge data + conversation history"
                 ```