Update app.py

app.py

@@ -47,8 +47,22 @@ try:
 except Exception as e:
     print(f"!!! ERROR LOADING prompts.yaml: {e} !!!")
 
-if isinstance(prompt_templates, dict) and 'final_answer' not in prompt_templates:
-    prompt_templates['final_answer'] = "{{final_answer}}"
+# ---> MODIFIED FIX <---
+# Ensure 'final_answer' key exists and is a dictionary containing 'pre_messages'
+if not isinstance(prompt_templates, dict):
+     prompt_templates = {} # Ensure it's a dict if loading failed
+
+if 'final_answer' not in prompt_templates:
+    print("!!! Adding missing 'final_answer' dictionary structure !!!")
+    prompt_templates['final_answer'] = {'pre_messages': "{{final_answer}}"} # Assign a dict with the required subkey
+elif not isinstance(prompt_templates['final_answer'], dict):
+    print("!!! 'final_answer' key exists but is not a dictionary. Overwriting. !!!")
+    prompt_templates['final_answer'] = {'pre_messages': "{{final_answer}}"}
+elif 'pre_messages' not in prompt_templates['final_answer']:
+    print("!!! Adding missing 'pre_messages' subkey to 'final_answer' !!!")
+    prompt_templates['final_answer']['pre_messages'] = "{{final_answer}}"
+# ---> END MODIFIED FIX <---
+
 
 agent = CodeAgent(
     model=model,