---
title: "Welcome"
description: "Give your AI agent a phone number. Patter handles telephony, speech-to-text, and text-to-speech so you can focus on your agent."
icon: "house"
---

# Patter

Connect any AI agent to phone calls with 4 lines of code. Patter handles telephony, speech-to-text, and text-to-speech so you can focus on your agent.

Patter is the open-source SDK that gives your AI agent a phone number. Point it at any function that returns a string and Patter handles the rest — telephony, speech-to-text, text-to-speech, and real-time audio streaming. You build the agent, we connect it to the phone. Works with Python and TypeScript, supports Twilio and Telnyx, and runs locally on your own infrastructure.

<Note>A hosted Patter Cloud option will return in a future release. For now the SDK runs entirely in your process — bring your own carrier and AI provider credentials.</Note>

<CardGroup cols={2}>
  <Card title="Quick Start" icon="rocket" href="/python-sdk/quickstart">
    Connect your first AI agent to a phone call in under 5 minutes.
  </Card>
  <Card title="Core Concepts" icon="lightbulb" href="/concepts">
    Understand agents, voice modes, and the audio pipeline.
  </Card>
  <Card title="Python SDK" icon="python" href="/python-sdk/overview">
    Full documentation for the Python SDK.
  </Card>
  <Card title="TypeScript SDK" icon="js" href="/typescript-sdk/overview">
    Full documentation for the TypeScript SDK.
  </Card>
</CardGroup>

## How it works

```
Phone Call → Telephony (Twilio/Telnyx) → WebSocket → Patter → STT → Your Agent → TTS → Caller
```

Your agent receives transcribed speech as text and returns a text response. Patter handles everything else — audio streaming, transcoding, provider APIs, and real-time voice synthesis.

## Key Features

- **4 lines of code** — Write an async handler. Patter does the rest.
- **Python & TypeScript** — Same API surface in both languages. Pick your stack.
- **Multiple voice modes** — OpenAI Realtime, ElevenLabs ConvAI, or custom Pipeline (STT + TTS).
- **Twilio & Telnyx** — Both telephony providers are fully supported with equal feature parity: DTMF, transfer, and cost tracking. Recording is Twilio-only.
- **Call transfer & recording** — Built-in system tools for transferring calls and enabling recording.
- **Guardrails** — Block terms, run custom checks, or replace responses before they reach the caller.
- **Built-in tunnel** — Cloudflare tunnel support, no ngrok required.
- **Real-time dashboard** — Live metrics, latency tracking, and cost monitoring.
