NO_RESPONSE_NEEDED. Whenever this sequence is met, the response generation stops.
You can then prompt the LLM to output nothing by writing something like:
Customize the synthesized speech
Make agent hold and respond nothing
Make a Retell agent stay silent on demand using the NO_RESPONSE_NEEDED stop sequence so it can hold for the caller without speaking or interrupting.
Sometimes you might want the agent to hold and not respond to the user, like when user says “hold on” or “give me a minute”.
We hard-coded a stop sequence in the LLM: