Developer / platform voice AI (not turnkey SMB-only)
Retell AI
https://www.retellai.com/ · HTTP check: 200
Warm transfer
yes
Transfers supported; AI fee stops after transfer per FAQ.
Booking
yes
Templates/platform support booking workflows; confirm per agent build.
Partner / affiliate
Pricing as published
Pay-as-you-go; listed all-in about $0.07–$0.31/minute depending on voice/LLM/telephony. Example calculator showed ~$0.11/min. No platform subscription required for starter. Enterprise custom.
Source: https://www.retellai.com/pricing
Best-fit verticals
builders / agencies, custom voice agents, businesses with developer resources
Key integrations
HubSpot, Zoho CRM, Pipedrive, Twilio, RingCentral, Stripe, Shopify, custom APIs, webhooks
Notes
Included because many SMBs encounter it via agencies; not a one-click receptionist.