Introducing Retell LLM Beta

Dear Retell Community,

We've been closely listening to your feedback and identifying the most significant friction points in building powerful voice AI agents that interact and take actions like humans. As a result, we're thrilled to announce the beta launch of Retell LLM, a unique framework for LLM agents that's optimized for real-time voice conversations and action executions.

1️⃣ Retell LLM (Beta)

Low Latency, Conversational LLM with Reliable Function Calls

Experience lightning-fast voice AI with an average end-to-end latency of just 800ms with our LLM, mirroring the performance featured in the South Bay Dental Office demo on our website. Our LLM has been fine-tuned for conciseness and a conversational tone, making it perfect for voice-based interactions. It is also engineered to reliably initiate function calls.

Single-Prompt vs. Stateful Multi-Prompt Agents

We provide two options for creating an agent. The Single-Prompt Agent is ideal for straightforward tasks that require a brief input. For scenarios where the agent's prompt is lengthy and the tasks are too complex for a single input to be effective, the Stateful Multi-Prompt Agent is recommended. This approach divides the prompt into various states, each with its own prompt, linked by conditional edges.

User-Friendly UI for Agent Creation and API for Programmatic Agent Creation

Our dashboard allows you to quickly create an LLM agent using prompts and the drag-and-drop functionality for stateful multi-prompt agents. You can seamlessly build, test, and deploy agents into production using our dashboard or achieve the same programmatically via our API.

Pre-defined Tool Calling Abilities such as Call Transfer, Ending Calls, and Appointment Booking

Leverage our pre-defined tool calling capabilities, including ending calls, transferring calls, checking calendar availability (via, and booking appointments (via, to easily build real-world actions. We also offer support for custom tools for more tailored actions.

Maintaining Continuous Interaction During Actions That Take Longer

To address delays in actions that require more time to complete, you can activate this feature. It enables the agent to maintain a conversation with the user throughout the duration of the function call. This ensures the voice AI agent keeps the interaction smooth and avoids awkward silences, even when function calls take longer.

2️⃣ SDK Update v3.4.0 Announcement

Please note, the previous SDK version will be phased out in 60 days. We encourage you to transition to the latest SDK version.

3️⃣ Status Page

Stay informed with system status on our new status page.

Status Page

4️⃣ Public Log in get-call API

To streamline your troubleshooting process, we've introduced a public log within our get-call API. This new feature aids in quicker issue resolution and smoother integration, detailed further at the link below.

See doc

We are dedicated to providing you with the best possible service and experience.

We welcome your feedback and are here to support you in making the most out of these new features.

Best regards,

Retell AI team 💛