Rasa
Rasa provides a framework to manage dialogue and conversational agents. Get started with a tutorial on building a voice agent with Rasa and Cartesia, from start to finish:
Tutorial: Build a Voice Agent with Rasa and Cartesia
Full tutorial for building a voice agent with Rasa and Cartesia.
For implementation details, see their documentation:
Rasa > Docs > Cartesia
Rasa documentation for using Cartesia TTS.