Retell AI

Retell AI is a developer-focused voice AI platform that enables companies to build and deploy AI phone agents at scale for both inbound and outbound call automation. Founded in 2023 and backed by Y Combinator and Alt Capital with $5.1 million raised across two rounds, Retell AI achieved approximately $50 million in annualized recurring revenue by early 2026, with 300-plus percent quarter-over-quarter user growth and over 50 million real-time AI phone calls processed every month.

The platform was named to the Wing VC Enterprise Tech 30 for 2026, recognizing it as one of the most important enterprise technology companies emerging in voice AI. Retell AI is built for engineering teams that need production-ready voice infrastructure: it provides real-time knowledge base syncing, multilingual call support in over 30 languages, HIPAA-compliant deployments, interruption handling, native CRM integrations with Salesforce and HubSpot, and webhook-based post-call data pipelines.

Unlike no-code platforms, Retell exposes full API control so developers can define custom conversation logic, build multi-turn dialogue systems, and integrate voice agents directly into existing product infrastructure. Common deployments include AI receptionists for healthcare clinics, outbound appointment reminder systems, inbound lead qualification bots, and customer support deflection for software companies.

Pricing starts at $0.07 per minute for standard voice agents with enterprise contracts for high-volume deployments.