Vapi

API

API for voice AI agents that answer and place phone and web calls

Price: Free credits, then paid
Access: Private API key

About

Vapi is a hosted platform for voice agents: you pick the speech-to-text, LLM and voice providers, and Vapi runs the call over the phone or the web. Billing is per minute, a $0.05/min hosting fee plus provider costs. An EU region is available.

What you can do with it

Build an inbound phone agent that answers customer support calls
Place outbound calls with an assistant for reminders or lead qualification
Add a voice assistant to a web or mobile app with the client SDKs

Get started

Sign up and copy your private API key from the dashboard ($5 free credit)
Create an assistant, then buy or import a phone number

Example

curl -X POST "https://api.vapi.ai/assistant" \
  -H "Authorization: Bearer $VAPI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Support Assistant",
    "model": {"provider": "openai", "model": "gpt-4o",
      "messages": [{"role": "system", "content": "You are a friendly phone support agent."}]},
    "voice": {"provider": "11labs", "voiceId": "cgSgspJ2msm6clMCkdW9"},
    "firstMessage": "Hi there, how can I help you today?"
  }'

Details

Hosting: Hosted service
Available in: Worldwide
Official SDKs: JavaScript/TypeScript, Python, Java, Ruby, C#, Go, Dart, Swift
MCP server: Remote