> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getbutter.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Welcome to Butter AI - Enterprise-Grade Voice Agents

<Info>
  **Butter AI is currently in Beta**. We are working closely with our early users to refine the platform and build the future of voice AI.
</Info>

Butter AI is a developer-first platform for building, deploying, and managing human-like Voice AI agents. We built Butter because we were frustrated with existing platforms that lock you into one provider and charge absurd markups.

Butter is different: **true multi-provider flexibility**, **transparent pass-through pricing**, and powerful enterprise features like **vector-based knowledge bases** and **custom API tools**.

## Why Butter AI?

Building voice agents from scratch is hard. You have to manage:

* **Latency**: Shaving off milliseconds to prevent awkward pauses.
* **Interruptions**: Handling when a user speaks over the bot.
* **Telephony**: SIP trunks, WebRTC, and phone number provisioning.
* **Tool Calling**: Connecting the AI to your backend systems.

Butter AI handles all of this infrastructure so you can focus on the conversation design and business logic.

## Key Features

<CardGroup cols={2}>
  <Card title="Sculpt Your Perfect Agent" icon="sliders">
    Mix and match LLMs (GPT-4, Claude, Gemini), voices (ElevenLabs, OpenAI, Deepgram), and providers. True flexibility, not vendor lock-in.
  </Card>

  <Card title="Feed It Intelligence" icon="book" href="/concepts/knowledge-base">
    Upload PDFs, docs, or plain text. Vector search powered by Pinecone makes your agent an expert on your business.
  </Card>

  <Card title="Extend Powers" icon="wrench" href="/concepts/tools">
    Custom API tools. Let your agent check inventory, book appointments, or update CRMs via webhook.
  </Card>

  <Card title="Deploy Anywhere" icon="phone" href="/concepts/phone-numbers">
    Bring your Twilio numbers or use LiveKit SIP. Inbound, outbound, transfer—it all works.
  </Card>
</CardGroup>

## Architecture

At a high level, Butter AI sits between the telephone network and your AI logic.

1. **Call Ingress**: We receive calls via Twilio or SIP.
2. **Transcribing**: Audio is streamed in real-time to an STT provider (e.g., Deepgram Nova-2).
3. **Reasoning**: The transcript is sent to an LLM (with your system prompt + RAG context).
4. **Speaking**: The LLM response is converted to audio via TTS and streamed back to the caller.

All of this happens in sub-second timeframes to ensure a natural conversation flow.