Patter: Inbound Agent

Minimal inbound voice agent — answer phone calls with AI in 4 lines of code.

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

• Creating a Patter client with Twilio + OpenAI credentials
• Defining a voice agent with a system prompt, voice, and first message
• Starting the embedded server to accept incoming calls
• OpenAI Realtime mode (all-in-one STT + LLM + TTS)

Next Steps

• Outbound Calls — place calls with AMD
• Tool Calling — add webhook-backed tools
• Custom Voice — pipeline mode with Deepgram + ElevenLabs
• Full documentation
• All templates

License

MIT