Update app.py

app.py

@@ -51,7 +51,7 @@ class BasicAgent:
             print("=== Sending prompt ===")
             print(prompt[:500])
             response = self.llm.chat.completions.create(
-                model="gpt-3.5-turbo",
+                model="GPT-4.1 nano",
                 messages=[
                     {"role": "system", "content": "You are a helpful AI assistant that provides clear and concise answers."},
                     {"role": "user", "content": prompt}