Zeus by ThunderPhone

Zeus is a fully agentic harness for voice AI: an AI agent that builds, tests and tunes your voice agents for you. Zeus configures agents on the ThunderPhone voice AI stack, which combines multiple models at once to achieve higher accuracy (99.4% on Big Bench Audio) and lower price (from 2¢/min) than competitors based on 3-step STT-LLM-TTS pipelines or single speech-to-speech models. Create an agent by talking to Zeus, or import one from Vapi, Retell, Bland or ElevenLabs.