Vapi

Vapi gives developers the building blocks for voice agents. It handles the hard parts of a phone conversation, such as listening, interruptions, turn taking and speaking back, so you can focus on what the agent should do. You can choose your own speech recognition, language model and voice providers, connect tools for booking or looking things up, and test agents before sending them live. Phone numbers and call routing are included. Vapi has pay as you go pricing with a starter credit. Teams use it to build receptionists, support lines and outbound calling.