Persona & prompt
The Persona tab has two fields that decide how your Vio agent sounds: the opening greeting it speaks the moment the call connects, and the system prompt that is its brain. Vio’s AI generator can write both for you, and you can personalise each with the caller’s name and any campaign data. The agent always greets first — the caller never has to speak before it does.
The two fields
- Opening greeting — the exact line the agent speaks the instant the call connects. Keep it short and natural, e.g. a warm hello plus an offer to help.
- System prompt — the agent’s brain. Write it in Markdown with an Edit / Preview toggle, and use the Expand-to-fullscreen editor for longer prompts. This is where you set the agent’s role, tone, rules, what to ask, and when to stop.
If you leave the system prompt blank, Vio falls back to a built-in Indian-language default persona that mirrors the caller’s language — so the agent will always speak, even before you write anything.
Let the AI write it for you
You don’t have to write a voice prompt from scratch. The Persona tab has an AI prompt generator:
- Generate prompt — describe the agent’s job in a short chat and Vio writes a voice-ready system prompt and a matching greeting for you.
- Improve prompt — refines your existing prompt in place, tightening it for spoken conversation without you starting over.
Voice prompts differ from chat prompts — sentences are shorter, there’s no formatting to read aloud, and the agent has to handle interruptions. The generator writes with that in mind.
Personalise with variables
Both the greeting and the system prompt support {{...}} placeholders. These pull in the caller’s name and any column from the CSV you upload for an Outbound campaign — so each call can be addressed personally.
- Use a placeholder like
{{name}}for a value. - Add a fallback with a pipe, e.g.
{{name|there}}, so there’s always something sensible to say.
A concrete greeting:
Hi {{name|there}}, thanks for calling — how can I help?If the CSV has a name, the caller hears “Hi Priya, thanks for calling”; if it doesn’t, they hear “Hi there, thanks for calling”.
A stray or unknown placeholder is never spoken literally. Vio resolves it to its fallback, and if there is no fallback it drops the placeholder quietly. Your caller will never hear “Hi curly-brace name curly-brace”.
Two directions of variables — don’t confuse them
- Personalisation variables (this page) flow into the call —
{{name}}and CSV columns fill the greeting and prompt. - Collected variables flow out of the call — fields the agent gathers from the caller and Vio extracts afterwards.
They are separate. See Variables for the data you collect from callers.
Frequently asked
Q. Does the Vio agent speak first, or wait for the caller? The agent speaks first. Your opening greeting plays the moment the call connects, so the caller is greeted immediately.
Q. What happens if I leave the system prompt empty? Vio uses a built-in Indian-language default persona that mirrors the caller’s language. The agent will still work — but a written prompt gives you control over its role, tone, and what it asks.
Q. Will the caller ever hear a broken {{placeholder}} out loud?
No. Every placeholder resolves to a value, to its fallback (e.g. {{name|there}}), or is dropped. A literal placeholder is never spoken.
Q. Do I have to write the prompt myself? No. Use Generate prompt to have Vio draft a voice-ready prompt and greeting from a short description, or Improve prompt to refine what you already have.
Next
Decide what the agent should ask for and record in Variables, or give it actions to take mid-call in Tools.