Capstone 03 — Real-Time Voice Assistant (ASR to LLM to TTS)

A voice agent that feels right has end-to-end latency under 800ms, knows when you have stopped talking, handles barge-in, and can call a tool without stalling. Retell, Vapi, LiveKit Agents, and Pipecat all hit this bar in 2026. They do it with the same shape: a streaming ASR, a turn-detector, a streaming LLM, and a streaming TTS, all wired through WebRTC with aggressive latency budgets at every hop. Build one, measure WER and MOS and false-cutoff rate, and run it under packet loss.