How a model or custom runnable output is passes as bot_message to the rails' prompt?

[abhijeetsourav]

The config folder for guardrails contains prompts for the model to check for various input and output rails, the prompts can contain user_input and/or bot_message.
I wanna know how both are passed when guardrails is wrapped with a langchain chain ( prompt | custom_runnable( ) ), what's the format for both, so that i can customize the output of my custom_runnable( ) for guardrails output rails checking.

Thanks in advance