Retell AI

API

Platform to build, test and deploy AI phone agents

Price: Free credits, then paid
Access: API key

About

Retell AI is a hosted platform for voice and chat agents with telephony, prompts, tools and call analytics built in. Voice agents cost $0.07 to $0.31 per minute, depending on the LLM and voice. Retell does not run services in the EU.

What you can do with it

Build a phone agent that answers inbound calls with your prompt and tools
Place outbound AI calls to customers from your own phone numbers
Test an agent in the browser with web calls before going live

Get started

Sign up and build an agent in the dashboard ($10 free credit)
Buy a phone number and assign the agent to it
Create an API key

Example

curl -X POST "https://api.retellai.com/v2/create-phone-call" \
  -H "Authorization: Bearer $RETELL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"from_number": "+14157774444", "to_number": "+12137774445"}'

Details

Hosting: Hosted service
Available in: Worldwide
Official SDKs: JavaScript/TypeScript, Python
MCP server: Remote