Writing/Series
Offhook
Building an open-source, self-hostable API for AI phone calls: STT, an LLM and TTS over a real phone line.
All parts
3 posts- Intro Building an open-source API for AI phone calls Why we built Offhook, what makes an AI phone call hard, and what this series will cover.
- Part 1 Latency is the product Where the time goes in one spoken turn, why the model's first token decides how a call feels, and the fixed cost we hadn't counted.
- Part 2 The phone part is the hard part What actually happens when an API places a phone call, and five ways two carriers doing the same job still managed to surprise us.