AI Agents: answering calls without a person

Build an assistant that answers a number, follows your instructions, draws on knowledge you give it, and hands off to a human when it should. Templates to start from, and what each tab in the editor changes.

An AI agent answers a phone number and holds a conversation. You give it a personality, a set of instructions, optionally some documents to draw on, and a rule for when to fetch a human. This article walks the editor tab by tab.

AI agents are a Telnyx feature. VICIfast gives you a place to build and manage them and puts the results next to the rest of your dialer, but the conversation itself runs on Telnyx and is billed by Telnyx.

Start from a template

Click New agent and pick a template rather than a blank one unless you have a clear reason. Each ships with instructions written for the job:

Front desk — answers, identifies why the person is calling, routes them.
Lead qualification — asks the questions that decide whether a lead is worth an agent’s time.
Support triage — sorts an existing customer’s problem before it reaches a person.
After hours — covers the times nobody is on the floor.

Blank agent is there for when none of those is close enough to edit.

Identity

The agent’s name, its voice, and the model behind it. Name and voice are what a caller experiences; the model is a cost and quality decision you can revisit once you have real calls to compare in Call Analytics.

Greeting

The first thing the caller hears. Worth more attention than its length suggests: it sets whether the person stays on the line, and it is the one line you can change without touching the instructions.

Instructions

The prompt. What the agent is for, what it must ask, what it must never say, and how to behave when it does not know something. Write it as you would brief a new hire on their first morning: specific, in order, with the edge cases named.

Capabilities

What the agent is allowed to do beyond talking — the actions available to it during a call. Turn on only what the job needs; every capability is another thing that can happen on a live call.

Knowledge

Documents the agent can draw on to answer questions it was not explicitly scripted for — a price list, a policy, an FAQ. Knowledge bases are shared between agents rather than owned by one, which is why they get their own tab on the agents list rather than living inside a single agent’s editor. A bucket only means anything through an agent, but burying it inside one agent would make "which agents use this?" unanswerable.

Handoff

Where the call goes when the agent should stop handling it. Point it at an in-group on your dialer and the caller is transferred to your floor with the context the agent gathered.

This is the setting most worth getting right. An agent with no handoff is an agent that can only ever end calls, which is fine for an after-hours message and wrong for everything else.

Versions

Every save is a version, and you can go back. Editing a live assistant is safe to offer because of this: if a prompt change makes calls worse, restore the previous version rather than trying to remember what you changed.

Give it a number

An agent does nothing until a number reaches it. Go to Phone Numbers, find the number, and attach it to the agent. The Answers with column will then name the agent, which is how you confirm it took.