TypeScript Quickstart

Patter connects an AI agent to a real phone number in four lines of TypeScript. This page walks you end-to-end: install, credentials, the four lines, and your first call.

Prerequisites

Node.js 18+
A Twilio or Telnyx account with a phone number you own
An AI provider key — OpenAI for the default Realtime engine, or any supported STT/TTS pair for pipeline mode

Step 1 — Install

npm install getpatter

Step 2 — Set environment variables

Each carrier and engine reads its credentials from the environment by default. The four-line quickstart below works as-is once these are set.

# Telephony — pick one carrier
TWILIO_ACCOUNT_SID=ACxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
TWILIO_AUTH_TOKEN=your_auth_token

# Realtime engine (default)
OPENAI_API_KEY=sk-xxxxxxxxxxxxxxxxxxxxxxxx

export TWILIO_ACCOUNT_SID=ACxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
export TWILIO_AUTH_TOKEN=your_auth_token
export OPENAI_API_KEY=sk-xxxxxxxxxxxxxxxxxxxxxxxx

$env:TWILIO_ACCOUNT_SID = "ACxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
$env:TWILIO_AUTH_TOKEN = "your_auth_token"
$env:OPENAI_API_KEY = "sk-xxxxxxxxxxxxxxxxxxxxxxxx"

Variable	Purpose
`TWILIO_ACCOUNT_SID`	Account SID from the Twilio console. Starts with `AC`.
`TWILIO_AUTH_TOKEN`	Auth token paired with the SID. Keep it secret.
`OPENAI_API_KEY`	Used by `OpenAIRealtime`, `WhisperSTT`, and `OpenAITTS`.

Using Telnyx instead? Swap the Twilio vars for TELNYX_API_KEY and TELNYX_CONNECTION_ID (plus optional TELNYX_PUBLIC_KEY for webhook signature verification) and use new Telnyx() in place of new Twilio(). See the Carrier page for all supported env vars.

Step 3 — The four-line quickstart

Create main.ts:

main.ts

import { Patter, Twilio, OpenAIRealtime } from "getpatter";

const phone = new Patter({ carrier: new Twilio(), phoneNumber: "+15550001234" });
const agent = phone.agent({ engine: new OpenAIRealtime(), systemPrompt: "You are a receptionist." });
await phone.serve({ agent, tunnel: true });

Want a custom greeting? Add firstMessage:

const agent = phone.agent({
  engine: new OpenAIRealtime(),
  systemPrompt: "You are a friendly receptionist for Acme Corp.",
  firstMessage: "Hello! How can I help?",
});

What each line does:

Import — the three primitives you need: the client, a carrier, and an engine. All three read credentials from environment variables by default, so no keys appear in source.
new Patter({...}) — build the client and bind it to your phone number. new Twilio() (or new Telnyx()) carries the carrier credentials; swap it to change providers.
phone.agent({...}) — describe the agent: the engine (OpenAI Realtime by default), the system prompt, and the first message it speaks on answer.
await phone.serve({ agent, tunnel: true }) — start the embedded server. tunnel: true spawns a Cloudflare tunnel and points your Twilio number at it automatically, so the agent is reachable from the PSTN without any additional DNS or firewall work.

tunnel: true is the dev shorthand. In production replace it with a stable webhook URL via the constructor:

const phone = new Patter({ carrier: new Twilio(), phoneNumber: "+15550001234", webhookUrl: "api.prod.example.com" });
...
await phone.serve({ agent });

Or use a pre-provisioned tunnel object: new Patter({ ..., tunnel: new StaticTunnel({ hostname: "agent.example.com" }) }). See Tunneling.

Step 4 — Run it

npx tsx main.ts

You’ll see the Patter banner, a Cloudflare tunnel URL, and a log line confirming the Twilio voice webhook was set to that URL.

Step 5 — Call the number

Pick up your phone, dial your Twilio number, and the agent will answer with "Hello! How can I help?". Start talking.

Using a different engine

OpenAI Realtime is the default. To switch engines, pass a different instance:

import { Patter, Twilio, ElevenLabsConvAI } from "getpatter";

const phone = new Patter({ carrier: new Twilio(), phoneNumber: "+15550001234" });
const agent = phone.agent({ engine: new ElevenLabsConvAI(), systemPrompt: "You are a helpful assistant." });
await phone.serve({ agent, tunnel: true });

new ElevenLabsConvAI() reads ELEVENLABS_API_KEY and ELEVENLABS_AGENT_ID from the environment. For the STT + LLM + TTS pipeline mode, pick each stage independently:

import { Patter, Twilio, DeepgramSTT, AnthropicLLM, ElevenLabsTTS } from "getpatter";

const phone = new Patter({ carrier: new Twilio(), phoneNumber: "+15550001234" });
const agent = phone.agent({
  stt: new DeepgramSTT(),                         // reads DEEPGRAM_API_KEY
  llm: new AnthropicLLM(),                        // reads ANTHROPIC_API_KEY
  tts: new ElevenLabsTTS({ voiceId: "rachel" }),  // reads ELEVENLABS_API_KEY
  systemPrompt: "You are a helpful assistant.",
  firstMessage: "Hello!",
});
await phone.serve({ agent, tunnel: true });

Swap new AnthropicLLM() for new OpenAILLM(), new GroqLLM(), new CerebrasLLM(), or new GoogleLLM() — tool calling works across all five. Need fully custom LLM logic? Drop llm and pass onMessage to serve() instead.

What’s next

Configuration

Every constructor option in one place.

Agents

Customize voice, model, tools, and guardrails.

STT providers

Deepgram, Whisper, Cartesia, Soniox, AssemblyAI.

TTS providers

ElevenLabs, OpenAI, Cartesia, Rime, LMNT.

Tools

Give your agent function-calling superpowers.

​TypeScript Quickstart

​Prerequisites

​Step 1 — Install

​Step 2 — Set environment variables

​Step 3 — The four-line quickstart

​Step 4 — Run it

​Step 5 — Call the number

​Using a different engine

​What’s next