Retell AI

About Retell AI

Retell AI is a developer-focused platform for building and deploying conversational voice agents across phone and web channels. It provides an SDK and API layer that handles the core infrastructure of voice interactions, including speech recognition, text-to-speech synthesis, and low-latency audio streaming, so developers can focus on defining agent logic and conversation flows rather than managing telephony or audio pipelines from scratch. The platform supports integration with large language models to power the conversational intelligence behind each agent. The primary use cases center on automating inbound and outbound phone calls at scale. Businesses use Retell AI to build agents that handle customer support inquiries, appointment scheduling, lead qualification, and after-hours call handling without requiring live human operators. The web channel support also allows voice agents to be embedded directly into websites or applications, extending the same automation to browser-based interactions. Retell provides tools for defining call flows, managing agent personas, and testing agent behavior before deployment, which reduces the iteration cycle during development. The platform is aimed squarely at developers and technical teams building voice automation into products or internal workflows, as well as agencies and SaaS companies that want to offer voice agent capabilities to their own customers. It is not a no-code tool in the traditional sense, though its abstractions lower the barrier compared to assembling a voice stack from individual components. Retell AI operates on a usage-based pricing model, charging based on call minutes consumed, which makes it accessible for early-stage projects while scaling with production workloads. The combination of a well-documented API, pre-built telephony integrations, and support for custom LLM backends positions Retell as a practical choice for teams that need reliable voice agent infrastructure without building the underlying layer themselves.

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