So , I am have been working with fabric Agents added via the Agents tab.
Things that I have tried out
1. Fabric Agents cannot be called from within the topics.
2 .'Create Generative Answer' cannot be used to generate answers from connected agent.
3. Fabric agent is automatically invoked at the end of a session, even when I use 'send a message' node
How to use CA to control user's query before fabric agent is invoked ?