Build an AI Voice Agent 2026
Stack - STT: Whisper or Deepgram - LLM: Claude or GPT - TTS: ElevenLabs or Cartesia - Telephony: Twilio - Or: Vapi managed Workflow 1. Caller dials 2. Twilio answers 3. Whisper transcribes 4. LLM generates reply 5. TTS speaks 6. Loop Latency - Target: <800ms total - Streaming throughout - Parallel where possible Cost - $0.05-0.20 per minute - Vapi: easier, costs more - Custom: cheaper at scale Us…