Vibe coding a voice agent used to mean wrangling three separate APIs—one for speech-to-text, one for the LLM, one for text-to-speech—and hoping your AI coding assistant could hold the glue logic together across all three. That's changed.

AssemblyAI's Voice Agent API collapses the entire pipeline into a single WebSocket. You send mic audio in, you get spoken audio back. Speech recognition, LLM reasoning, text-to-speech, turn detection, and barge-in handling all happen server-side. The integration surface is small enough that Claude Code, ChatGPT, or Cursor can generate a working voice agent on the first prompt.

This post is a prompt guide. You'll get the exact prompts to build different types of voice agents, the setup that keeps your AI coding agent grounded in current docs, and the follow-up prompts that customize behavior without you touching the code directly.…