Introdduce a default callback mechanism

app.py

@@ -57,6 +57,7 @@ from pydantic import BaseModel
 from strands import Agent
 from strands.agent.conversation_manager import SlidingWindowConversationManager
 from strands.models.openai import OpenAIModel
+from strands.handlers.callback_handler import PrintingCallbackHandler
 
 # Import confluence-ingestor
 from confluence_ingestor import ConfluenceRAG
@@ -397,7 +398,14 @@ def create_enhanced_agent():
             should_truncate_results=True, # Enable truncating the tool result when a message is too large for the model's context window
         )
 
-        _cached_agent = Agent(model=model, system_prompt=system_prompt, tools=tools, conversation_manager=conversation_manager)
+        # The default callback handler prints text and shows tool usage
+        _cached_agent = Agent(
+            model=model,
+            system_prompt=system_prompt,
+            tools=tools,
+            conversation_manager=conversation_manager,
+            callback_handler=PrintingCallbackHandler()
+        )
     else:
         # Create a conversation manager with custom window size
         conversation_manager = SlidingWindowConversationManager(
@@ -405,7 +413,13 @@ def create_enhanced_agent():
             should_truncate_results=True, # Enable truncating the tool result when a message is too large for the model's context window
         )
 
-        _cached_agent = Agent(system_prompt=system_prompt, tools=tools, conversation_manager=conversation_manager)
+        # The default callback handler prints text and shows tool usage
+        _cached_agent = Agent(
+            system_prompt=system_prompt,
+            tools=tools,
+            conversation_manager=conversation_manager,
+            callback_handler=PrintingCallbackHandler()
+        )
 
     return _cached_agent