# Introduction

Build AI voice agents for SIP-based inbound call handling.

Leilani answers calls, talks with callers in real time, searches configured knowledge, runs external tools, routes people through your directory, and gives operators a console for live supervision.

## What is Leilani?

Leilani is an AI voice orchestration layer for organizations that want inbound calls to be more capable than a static phone tree.

It sits between callers and your SIP environment so an agent can:

- answer inbound calls automatically
- speak with callers in natural conversation
- collect structured details
- search your [Knowledge Base](knowledge-base.md)
- use allowlisted [Web Search](web-search.md)
- run [Functions](functions.md) and remote [MCP Servers](mcp-servers.md)
- route callers through your [Directory](directory.md)
- perform cold or warm transfers
- support operators from the [Dashboard](dashboard.md) and [Inbox](inbox.md)

Leilani augments your existing telephony stack. It does not require replacing your PBX, queues, extensions, or operational systems.

## How Leilani works

Every agent combines five layers.

**SIP connection**

Registers to your SIP environment so Leilani can receive inbound calls and send transfer actions to destinations your PBX understands.

**Live voice handling**

Handles speech recognition, model reasoning, spoken responses, turn-taking, DTMF input, and call control during the active call.

**Agent configuration**

Controls the agent's connection details, voice, greeting, language hint, max call duration, transcript recipient, owner, users, web search allowlist, and operating instructions.

**Knowledge and tools**

Gives the agent structured ways to retrieve information and take action through uploaded documents, crawled pages, Functions, caches, JSON Web Tokens, MCP tools, and approved web search domains.

**Operator console**

Shows registration state, live calls, transcripts, manual transfer controls, hangup controls, recent usage, and available funds.

## Core building blocks

[Quickstart](quickstart.md)

Create an agent, configure SIP, add first-call behavior, route a test call, and monitor it live.

[Agents](agents.md)

Understand the main configuration and resource boundary in Leilani.

[Calls](calls.md)

Understand the live call lifecycle, built-in call tools, Dashboard, Inbox, Directory, and transfer behavior.

[Knowledge](knowledge.md)

Add source material through documents, website crawl jobs, and optional web search.

[Tools](tools.md)

Connect HTTP webhooks, email, SMS, TEL transfers, MCP servers, caches, and JWT credentials.

[Operations](operations.md)

Monitor registration, balance, live calls, usage, and production readiness.

## Key capabilities

- **Inbound call automation:** answer SIP calls and run conversational callflows without rebuilding your whole phone system
- **Natural intake:** collect names, contact details, intent, urgency, identifiers, and workflow-specific fields
- **Directory routing:** search caller-facing names and transfer to extensions, queues, IVRs, or outside numbers
- **Warm handoffs:** screen transfer targets, brief recipients, and fall back to message capture when configured
- **Knowledge retrieval:** answer factual questions from uploaded documents and web-crawled reference material
- **External actions:** call HTTP APIs, send email, send SMS, transfer calls, and use MCP tools
- **Credential support:** generate JWTs, store values in caches, and substitute cached values into Function calls
- **Operator supervision:** monitor live transcripts, transfer manually, hang up, and track registration
- **Usage funding:** add and monitor agent funds through [Billing & Usage](billing-and-usage.md)

## Choose your path

[Set up an agent](configuration.md)

Configure SIP, voice, greeting, language, users, transcript email, web search allowlist, and max duration.

[Write production instructions](instructions.md)

Shape the agent's role, tone, callflow, tool usage, safety, and escalation behavior.

[Add routing](directory.md)

Create a directory manually, upload a CSV, or sync from an external URL so callers can ask for people, departments, queues, and roles by name.

[Give the agent knowledge](knowledge-base.md)

Upload internal reference text or crawl website content for frequently updated public material.

[Connect tools](functions.md)

Build Functions for webhooks, email, SMS, transfers, cached lookups, JWT-backed credentials, and MCP-hosted workflows.

[Operate live calls](inbox.md)

Use the Inbox during launches, supervised workflows, and live-call troubleshooting.

## Common use cases

**Front desk and reception**

Answer common questions, collect caller intent, route to staff or departments, and capture messages when a warm transfer does not complete.

**Support intake**

Identify the issue, gather required details, search support material, create tickets or follow-up tasks, and route urgent callers.

**Appointment and callback workflows**

Collect scheduling details, send confirmations, create callback requests, or transfer callers to the right queue.

**After-hours coverage**

Handle routine calls when staff are unavailable, capture structured messages, send summaries, and escalate only when rules require it.

**Sales and qualification**

Qualify inbound leads, gather contact and need details, notify the right team, or route high-value calls immediately.

**Operational routing**

Use synced directories, queues, IVRs, on-call roles, and warm handoffs to keep routing logic modular and caller-friendly.