Speech-native voice AI infrastructure and APIs for developers building low-latency, natural-sounding conversational voice agents.
What it does
Ultravox is a research and product company that built a speech-native AI model and inference stack for real-time voice agents, avoiding the speech-to-text-to-speech pipeline that adds latency and loses tone/cadence cues. It offers developer APIs, SDKs, and telephony integrations to build conversational voice AI.
Core features
Speech-native model that processes audio directly without transcription bottleneck
Neural voice activity detection for natural turn-taking
REST APIs and SDKs for web and mobile integration
Built-in telephony provider integrations
Self-managed inference stack for low latency at scale
Open-weight core models available on Hugging Face
Best for
→Building real-time conversational voice agents for customer support
→Adding voice interfaces to existing applications
→Powering telephony-based AI voice assistants
→Research and experimentation with speech-native AI models
Pricing
Pay Go
$0/month
Pro
$100/month