Retell AI

Retell AI is a platform for building AI voice agents that can handle phone calls on their own. It's made by the company of the same name and targets mainly developers, startups, and businesses that want to automate inbound and outbound calling without building an entire voice stack from scratch.

It works like this: you set up a call script for the agent, connect a knowledge base, and link it to a phone line. The agent then listens to the caller in real time, replies in a natural voice with very low latency, and after the call delivers a transcript, analysis, and quality evaluation.