Detect voicemail and IVR with outbound phone agents

Answering Machine Detection (AMD) has been integrated into LiveKit Agents, enhancing their ability to identify whether an outbound call reaches a human, voicemail, IVR, or is unavailable, without requiring additional plugins. This technology allows agents to quickly determine the nature of the call within the first second, enabling appropriate responses such as leaving a message, navigating menus, or ending the call, which improves efficiency and reduces costs. AMD operates outside the agent's main loop, using a short-circuiting rule and LLM classification to ensure rapid and accurate detection, with a strong reliance on transcripts from the STT pipeline. The system is highly configurable, allowing for various levels of conservatism depending on the use case, and supports auto-IVR navigation and interruption protection to prevent unnecessary resource use. Benchmarked against diverse datasets, the best-performing model pairing achieves high accuracy and quick decision times, with options to swap models depending on user preference. AMD is now available for Python and Node.js, with extensive documentation for configuration and integration, aiming to streamline the workflow of outbound call agents.