Hello @everyone, I am going a bit insane. I need to make this voice agent that will participate in a roundtable, so it has to mostly shut up and just speak when spoken to. No matter how much I emphasize it in the instructions, it will just talk unprompted, does anyone have any idea how I can solve this?

Set explicit instructions in the prompt, adjust waitSeconds for delay before speaking, enable Smart Endpointing to detect pauses, and configure it to stop speaking when interrupted by others.

If you mean trigger phrase like, "Hey Siri" I don't believe its possible on VAPI. VAPI has strict BOT > USER > BOT... turn taking. Prompt only affects LLM behavior, and LLMs don't really respond with empty strings. LLM does not decide if turn taking takes place or not. You can't prompt this. As Kings said, try the start/stop speaking plans with different timing, make interruption 0.1s, but it will still talk if call is active and there's pause greater than your settings.

Start / stop speaking plans aren’t what you’re looking for it’ll just add more delay but you’ll have the same problem