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Booking Oct / Nov · 2 app slots left

AI voice agents · new

Realtime AI voice agents, on your phone lines and in your app.

Custom voice agents that answer calls, book appointments, qualify leads, and talk to users inside your app — built on LiveKit and connected to your phone numbers over SIP. You own the code and the accounts, with no per-minute platform markup.

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Realtime voiceLiveKitSIPTwilio

Live demo

Call our AI receptionist.

Luna answers LunarBuild's line, answers questions about the studio, and books real calls on Neil's calendar. Built on LiveKit with the same stack we ship for clients.

Call +1 (415) 417-6123

Browser calls use your microphone. Calls are capped at 7 minutes and may be recorded.

Things to try

  • Ask what LunarBuild builds and what an app costs
  • Interrupt it mid-sentence — it stops and listens
  • Book a real 20-minute call with Neil for next week
  • Ask if it's a robot
What's included

Everything it takes to ship.

  • Conversation design

    Call flows, prompts, escalation rules, and what the agent should never say.

  • Realtime voice pipeline

    Speech-to-text, LLM, and text-to-speech tuned for low latency and natural turn-taking.

  • LiveKit agents

    Agents built on LiveKit — self-hosted or LiveKit Cloud.

  • SIP trunking & telephony

    Inbound and outbound calls via Twilio, Telnyx, or your existing SIP provider, with call transfer to humans.

  • Tools & integrations

    Calendars, CRMs, databases, and your own APIs — so the agent can actually do things.

  • In-app voice

    Voice assistants inside your iOS, Android, Flutter, or web app.

What we build

Types of ai voice agents we take on.

  • AI receptionists

    Answer every call, handle FAQs, and book appointments 24/7.

  • Outbound calls

    Reminders, confirmations, follow-ups, and lead qualification.

  • Support lines

    Resolve common requests and hand off to a human with context.

  • In-app voice assistants

    Hands-free help and coaching inside your mobile app.

How it works

From first call to launch.

  1. 01

    Scope

    A free call to map the calls you want handled and how success is measured.

  2. 02

    Prototype

    A working agent on a test number, so you can call it yourself.

  3. 03

    Integrate

    Phone numbers, call transfer, calendars, and CRM.

  4. 04

    Launch & tune

    Go live, review real calls, and improve accuracy and latency.

AI voice agents

Fixed quote

Test number before go-live

  • Fixed quote within 24 hours
  • Your phone numbers and accounts
  • Code in your GitHub
  • Per-minute cost estimate up front
FAQ

Questions we get on every call.

Can't find what you need? Email us or book a 20-min call.

Can I try one of your voice agents?
Yes — call our AI receptionist, Luna, on +1 (415) 417-6123. She answers questions about LunarBuild and books real calls on our calendar, built on the same LiveKit stack we use for clients. Voice agents are our newest service line, so Luna is our public demo rather than a client case study; for your project, you call a working prototype on a test number before anything goes live.
Why LiveKit instead of a hosted voice platform?
Hosted platforms are quick to start but charge per minute and limit what you can customise. LiveKit gives you an open-source realtime stack you can self-host or run on LiveKit Cloud, with full control over models, latency, and cost. If a hosted platform is the better fit for your volume, we'll say so.
Can the agent use our existing phone numbers?
Usually, yes. We connect over SIP to providers like Twilio or Telnyx, or to your existing SIP trunk, and can transfer calls to your team.
What does a voice agent cost to run?
Running cost is per minute: speech-to-text, the language model, text-to-speech, and telephony. We give you an estimate for your call volume before we build.
More services

Work with us on the whole product.

Ready when you are

Tell us about your project.

Pick a time below for a free 20-minute call. We'll talk through scope and timeline, tell you which stack we'd pick and why, and send a fixed quote within 24 hours. No slides, no pitch deck.

Free 20 minutes Fixed quote in 24h NDA on request