Vapi wires STT + LLM + TTS into sub-second voice agents that answer phones, book appointments and run voice UIs — the plumbing for "AI receptionist" products.
Capabilities
Capabilities
- Realtime voice agent orchestration, phone numbers, tool calls mid-conversation
- ~$0.05/min + model costs; free dev tier
Best for
- Cloning AI phone agents, voice assistants, call-screening products
Not for
- Non-realtime audio (batch TTS/STT directly is cheaper)