Retell provides the infrastructure for voice agents. A developer defines an agent’s prompt and tools, connects a phone number, and the platform handles speech recognition, the language model, speech synthesis, and call control with natural turn-taking and interruption handling.
Use cases include answering customer calls, scheduling appointments, qualifying leads, and following up with customers. Integrations with calendars and CRMs let agents take actions, and analytics show call outcomes. Handoff to humans is supported.
Retell is paid, billed by minutes of use. Voice calls are regulated, with rules on consent and disclosure that AI is speaking. Alternatives include Vapi, Bland AI, Synthflow, Twilio ConversationRelay, and PolyAI. Retell suits developers and businesses building voice agents.