# AI voice agents


# AI voice agents

An **agent** is a single AI voice persona that places and answers phone calls for your organization. It has its own language model, voice, greeting, behavior and tools — everything that decides how a call sounds and what the agent can do. You build and tune agents in the agent builder at **/agent/setup**, then test and publish them. This page explains the agent concept and maps every builder tab to its documentation.

## What an agent is

Each agent bundles together:

- a **voice pipeline and language model** that drive the conversation;
- a **voice** that speaks and a transcriber that listens;
- a **system prompt, greeting and key messages** that shape its personality and how it opens and closes a call;
- **engine behavior** that controls pacing — interruptions, silence and turn-taking;
- **calling settings** for inbound and outbound use;
- optional **knowledge** and **tools** so it can answer from your documents and take real actions; and
- **guardrails and channels** for compliance and for reaching people on messaging apps.

Agents live inside projects, following the **Organization → Projects → Agents** structure from the [overview](../introduction#the-three-tier-model). Once an agent is published you can point campaigns and inbound numbers at it.

## The builder tab model

![The agent builder and its tabs](/img/screenshots/portal/agent-tab.png)
*The agent builder. Tabs across the top (Agent, Model, Voice, Behavior, Calling, Tools, Calendar, Workflow, Function Logs, Guardrails, Channels) each configure one part of the agent.*

The builder at **/agent/setup** organizes configuration into eleven tabs. You move through them left to right, saving as you go. The core tabs each have their own documentation page:

- **Agent** — name, description, use case and starting template, plus the **system prompt**, the **greeting** and the **end / fallback / busy / voicemail** messages, and the **Published** and **Active** toggles. This is where every new agent begins; see [Create your first agent](./create-agent).
- **[LLM](./llm)** — the voice pipeline mode, LLM provider and model, temperature, token limits, advanced parameters, a fallback model, and the **RAG / knowledge-base** linkage (see [Knowledge & RAG](./knowledge-rag)).
- **[Audio (Voice & audio)](./voice-audio)** — multi-provider speech-to-text and text-to-speech (provider, model, voice, and provider-specific tuning).
- **[Engine (Conversation behavior)](./engine-behavior)** — barge-in and interrupt handling, voice-activity-detection padding, response delay, silence handling and filler words.
- **[Calling](./calling-telephony)** — inbound/outbound, maximum duration, auto-hangup, assigned numbers and webhooks.
- **[Tools](./tools-mcp)** — bind the agent's functions, connect MCP servers, and open the **Workflow Builder**.
- **Calendar** — connect Google or Outlook via OAuth so the agent can work with availability.
- **[Workflow](./workflow-builder)** — a visual call-flow builder, launched from the Tools tab.
- **Function Logs** — per-function metrics: call counts, latency and errors for the functions this agent uses.
- **[Guardrails](./guardrails)** — compliance and data-collection controls (covered below).
- **[Channels](../channels)** — reach people on messaging apps: WhatsApp, Telegram, Facebook Messenger and an embeddable web widget.

### Workflow Builder

The **Workflow** tab opens a visual call-flow builder (launched with the **Open Workflow Builder** button on the Tools tab). It lets you design deterministic, node-based call flows — questions, conditions, tool calls, webhooks and transfers — for agents that need a scripted path rather than open-ended conversation.

### Function Logs

The **Function Logs** tab shows how the agent's bound functions are performing during real calls: how often each function is called, its latency, and any errors. Use it to spot a slow or failing tool before it hurts call quality.

### Guardrails

The **Guardrails** tab keeps the agent safe and compliant. It controls:

- **Content guardrails** — a list of **prohibited topics** the agent avoids and redirects away from.
- **PII handling** — how personally identifiable information is treated in transcripts (**mask**, **redact** or **allow**), plus a per-type **transcript PII redaction** picker (SSN, credit card, email, phone, address, date of birth, bank account).
- **Compliance mode** — **Standard**, **Strict**, **HIPAA** or **PCI-DSS**; the stricter modes enable additional security measures and logging.
- **Data collection** — the **collected fields** the agent tries to capture and the **required fields** it must obtain (prompting the caller if they're missing).
- **Post-call analysis** — opt-in **auto-summarize**, **sentiment analysis** and **intent detection**.

:::note[Channels are messaging apps, not email]

The **Channels** tab is for messaging apps — WhatsApp, Telegram, Facebook Messenger and a web widget. Email follow-up is not a channel: it's the **send_email** function on the [Tools](./tools-mcp) tab.

:::

:::tip[Start small]

You don't have to fill in every tab to get going. A name, a model, a voice and a greeting are enough for a first test. Add knowledge and tools once the basics sound right.

:::

## Test before you publish

The builder pairs with two test surfaces so you can try an agent before it touches real calls:

- **Voice test** at **/agent/interface** — talk to the agent and hear it respond.
- **Chat test** at **/agent/chat** — exchange text turns to check logic and prompts quickly.

The full path from a blank agent to a published one is in [Create your first agent](./create-agent).

## Next steps

- [Create your first agent](./create-agent)
- [Configure the language model](./llm)
- [Set up voice and audio](./voice-audio)
- [Shape conversation behavior](./engine-behavior)