Add final_answer key to prompt_templates for handling agent failures

app.py

@@ -60,7 +60,14 @@ image_generation_tool = load_tool("agents-course/text-to-image", trust_remote_co
 
 with open("prompts.yaml", 'r') as stream:
     prompt_templates = yaml.safe_load(stream)
-    
+
+# smolagents==1.13.0 requires this key when max_steps is reached without a final_answer call,
+# but the course template's prompts.yaml doesn't define it.
+prompt_templates.setdefault("final_answer", {
+    "pre_messages": "An agent tried to answer a user query but it got stuck and failed to do so. You are tasked with providing an answer instead. Here is the agent's memory:",
+    "post_messages": "Based on the above, please provide an answer to the following user task:\n{{task}}",
+})
+
 agent = CodeAgent(
     model=model,
     tools=[final_answer, get_current_time_in_timezone, web_search_tool, image_generation_tool], ## add your tools here (don't remove final answer)