Patter: Outbound Calls

Place outbound calls with answering machine detection (AMD) and voicemail drop.

Part of the Patter Voice AI SDK.

Prerequisites

• Twilio account with a phone number
• OpenAI API key with Realtime access

Quick Start

Python

cd python
cp ../.env.example .env   # fill in your keys
pip install -r requirements.txt
python main.py

TypeScript

cd typescript
cp ../.env.example .env   # fill in your keys
npm install
npx tsx main.ts

Environment Variables

Variable	Required	Description
OPENAI_API_KEY	Yes	OpenAI API key with Realtime access
TWILIO_ACCOUNT_SID	Yes	Twilio account SID
TWILIO_AUTH_TOKEN	Yes	Twilio auth token
TWILIO_PHONE_NUMBER	Yes	Your Twilio phone number (E.164)
WEBHOOK_URL	No	Public URL for webhooks (auto-tunneled if omitted)

What This Demonstrates

• phone.call() for placing outbound calls
• machineDetection to detect answering machines via AMD
• voicemailMessage to leave a pre-recorded message on voicemail
• Lifecycle callbacks for call events

Next Steps

• Inbound Agent — answer calls with AI
• Tool Calling — add webhook-backed tools
• Custom Voice — pipeline mode with Deepgram + ElevenLabs
• Full documentation
• All templates

License

MIT