Prototyping Voice Agents with LiveKit in 2025

Our Prototype Development capability thrives on fast feedback. In 2025 the LiveKit ecosystem — Agents SDK, third-party voice partners, and tooling around OpenAI’s Realtime API — makes it possible to stand up expressive, low-latency voice experiences in days.

Architecture at a Glance

Caller ↔︎ LiveKit Room ↔︎ Agent Runtime ↔︎ LLM + Voice Services ↔︎ Internal APIs

• LiveKit Agents let Node.js or Python services join rooms as first-class participants, streaming audio, video, and metadata in real time. (Docs)
• Speechify partnership (May 2025) delivers >1,000 voices across 60 languages with pricing that scales ($10 per million characters ≈ 2,000 minutes). (Speechify)
• PlayAI + LiveKit (March 2025) brings ultra-emotive dialog models routed through LiveKit Agents, perfect for concierge-style prototypes. (Play.ht)
• OpenAI Realtime API provides multimodal grounding — the agent can “see” or “click” in addition to talking — while LiveKit handles session orchestration.

Prototype Roadmap

Day 0: Scope + Guardrails

• Define the outcome metric (conversion, CSAT, qualified lead rate).
• Validate data access: CRM notes, knowledge base, escalation workflows.
• Draft failure policies (human handoff triggers, redaction rules).

Day 1-2: Skeleton Build

1. Spin up a LiveKit project and configure the Agents runtime.
2. Scaffold an Interaction Orchestrator that:
   • Joins a room.
   • Performs speech-to-text (OpenAI Whisper, ElevenLabs, or Deepgram).
   • Publishes synthesized speech back through Speechify or PlayAI voices.
3. Implement tool stubs for CRM lookup, scheduling, and follow-up tasks.

Day 3-4: Intent + Memory

• Add vector + graph retrieval (CAPRAG-inspired) for contextual answers.
• Persist short-term memory per caller: intent, sentiment, key objections.
• Script “golden path” demos to validate latency, voice quality, and handoff.

Day 5-7: Pilot Hardening

• Instrument metrics: latency, interruption handling, first-contact resolution.
• Layer in consent prompts, profanity filters, and audit logging.
• Conduct operator ride-alongs; capture friction for fast iteration.

Starter Code Snippets

Agent bootstrap

import { Agent, RoomServiceClient } from "@livekit/agents-node";
import { createRealtimeClient } from "@openai/realtime-api";

export const startAgent = async () => {
  const roomClient = new RoomServiceClient({
    apiKey: process.env.LIVEKIT_API_KEY ?? "",
    apiSecret: process.env.LIVEKIT_API_SECRET ?? "",
    url: process.env.LIVEKIT_URL ?? "",
  });

  const agent = new Agent({ roomClient });

  agent.onParticipantConnected(async (participant) => {
    const realtimeClient = await createRealtimeClient({
      apiKey: process.env.OPENAI_API_KEY ?? "",
      baseUrl: "https://api.openai.com/v1/realtime",
    });

    // Wire transcription + synthesis
    agent.pipeAudio(participant, realtimeClient);
  });

  await agent.join({
    roomName: "prototype-support-line",
    identity: "voice-agent",
    metadata: { persona: "concierge" },
  });
};

Tool invocation pattern

type FollowUpTask = {
  contactId: string;
  summary: string;
  dueAt: Date;
};

export const scheduleFollowUp = async (task: FollowUpTask) => {
  // Call internal API with auditable payload
};

Demo Checklist

• Low latency: Target < 300 ms from user utterance to agent response.
• Emotionally aware voices: Select Speechify or PlayAI voices that match the brand tone.
• Turn detection: Ensure the agent waits for natural pauses before interrupting.
• Escalation ready: Human agent can join the LiveKit room instantly with full transcript context.

Proving Value in Week One

1. Run 20+ controlled calls and benchmark against human-handled metrics.
2. Capture qualitative feedback from operators and customers.
3. Present latency, containment, and satisfaction dashboards to stakeholders.
4. Secure the runway for “Production Alpha” by aligning on data, observability, and compliance gaps.

What Comes After the Prototype

• Transition the codebase into the engineering runway with automated testing, feature flags, and infrastructure-as-code.
• Expand language and channel coverage — LiveKit handles video, screen share, and data tracks out of the box.
• Start training playbooks for marketing, sales, and support teams so they can design new flows on top of the voice agent.