AI voice agent development services
Production voice agents built on Vapi, Retell, and LiveKit — deployed in 4 to 8 weeks, priced per call at $0.05 to $0.15, and integrated with your existing CRM from day one.
A real phone call. Not a web widget, not a chatbot with voice playback.
An AI voice agent is software that answers or makes phone calls for you. The caller dials a number. The agent picks up. It listens, reasons, and responds in real time with sub-second latency. It books appointments, qualifies leads, confirms orders, answers FAQs, and transfers to a human when the conversation goes off script.
Under the hood, a voice agent is a pipeline. The caller's audio streams to a speech-to-text model like Deepgram or Whisper. The transcript goes to a language model (GPT-4o, Claude) with your business context and a system prompt. The response runs through a text-to-speech model like ElevenLabs or Cartesia that speaks back in a natural voice. Orchestration sits on a platform — Vapi, Retell, or LiveKit.
The difference between a voice agent that sounds robotic and one that passes for human is not the LLM. It's the turn-taking model, the voice synthesis choice, and the latency budget. That's where most implementations fail.
We've built production voice agents since 2023, starting with internal deployments at a 10M+ player iGaming operator. We know where they break.
Six types of voice agent we build.
Picked based on your call volume, call pattern, and compliance profile. Not based on which is easiest for us.
Inbound support voice agents
24/7 phone coverage for FAQs, order status, appointment changes, and basic troubleshooting. Escalates to a human when the caller's intent falls outside the trained scope.
Typical deflection: 70–85% of inbound calls resolved without transferOutbound lead qualification agents
Calls inbound web leads within 60 seconds, qualifies them in under three minutes, and books a sales call on your calendar.
Typical lift: 3–5x contact rate vs. manual dialing, at a fraction of the cost per qualified leadAI receptionists for clinics & service businesses
Front-desk replacement for medical, dental, veterinary, and legal offices. Books appointments, collects insurance info, confirms cancellations, and routes emergencies. HIPAA-compliant on self-hosted or compliant cloud.
Reference deployment: 100% answer rate, +28% bookings in 90 daysReservation & booking agents
Restaurants, hotels, salons, fitness studios. The agent handles new bookings, modifications, waitlists, and no-show follow-up — 24 hours a day, in 10+ languages.
Milina deployment: 50+ calls/weekend night at $0.09/callReminder & renewal agents
Insurance renewals, payment reminders, subscription winback. Voice calls convert 3–4x higher than SMS in our production data, at comparable cost per contact.
Convert 3–4x higher than SMS at similar per-contact costVoice-enabled internal assistants
A voice agent your sales or ops team calls during the day: "Find me last month's pipeline by stage. Book a demo with the Miller account." Voice interface on top of HubSpot, Salesforce, or GoHighLevel.
Deployed on top of: HubSpot · Salesforce · GHL · ZohoWhich voice platform should you use?
Three platforms dominate production voice AI in 2026: Vapi, Retell, and LiveKit. They are not interchangeable.
Managed infrastructure, drag-and-drop flows, pre-integrated telephony. You can have a working prototype in a day. We recommend Vapi for simple single-intent agents (FAQ, basic booking) and for teams that need to ship in two weeks without touching infrastructure.
Proprietary turn-taking model delivers roughly 600ms response latency — the current production benchmark. SOC 2 Type II makes it a default choice for US healthcare and financial services clients who need attestations but can't self-host.
Open-source, self-hostable stack. Our Milina deployment runs at $0.09 per 3-minute call. The only real option for large-volume deployments where per-minute fees compound. Tradeoff: engineering lift — you pick and wire your own STT, LLM, and TTS providers.
We're platform-agnostic. In the discovery workshop we audit your use case, compliance profile, and call economics — and recommend the stack that fits, not the one with the best affiliate program.
What production actually looks like.
Three deployments. Real metrics. None of these exist on a demo slide.
Reservation and inquiry handling. $0.09 per call, 91% completion.
LiveKit + Deepgram STT + GPT-4o-mini + Cartesia TTS. Handles 50+ calls per weekend night. 91% completion rate — the caller's goal achieved without a human transfer. During shadow mode, callers routinely didn't realize they were talking to AI until we told them.
HIPAA AI receptionist. 100% answer rate, 28% booking lift.
HIPAA-compliant deployment on self-hosted LiveKit inside the client's VPC. 100% answer rate on inbound calls, up from 62%. The rest used to go to voicemail and were lost. 28% increase in booked appointments over the first 90 days.
QA assessment system. 66% → 91% accuracy, 2% → 25% coverage.
Not a voice agent, but worth mentioning because the methodology matters. We took a live QA audit system from 66% to 91% accuracy by switching from direct prompting to schema-guided reasoning. This is the level of rigor we apply to every voice deployment.
Voice AI projects come in three shapes.
No hourly billing on development. No surprise invoices. If we hit an unexpected technical blocker that requires more work, that's our risk — that's what the discovery workshop scopes out.
| Engagement | Scope | Price | Timeline |
|---|---|---|---|
| Discovery workshop | Use-case audit, architecture doc, fixed-scope proposal | $1,500–$3,000 | 1 week |
| Voice agent MVP | Single use case, one channel, core CRM integration | $6,000–$12,000 | 3–4 weeks |
| Production voice agent | Multilingual, multi-intent, full CRM + analytics | $15,000–$30,000 | 6–10 weeks |
| Monthly retainer | Ops, prompt tuning, new intents, observability | $2,000–$8,000/mo | Post-launch |
Per-call production costs land between $0.05 and $0.15 depending on call length, LLM tier, and voice platform. We model this for you in the discovery workshop so you know your unit economics before you commit to a build.
From discovery to production in 4–8 weeks.
No month-long "we're working on it" silences. Weekly demos on real data from week one.
Discovery workshop
A one-week paid audit. You get an architecture document, a stack recommendation, a unit-economics model, and a fixed-price proposal. If you don't move forward with us, you keep the document.
Build
Daily Slack access and weekly demos on real data from your systems. No month-long silences. Fixed scope, fixed price.
Shadow mode
The voice agent runs in parallel with your human team. We measure completion rate, transfer rate, caller sentiment, and per-call cost against the real baseline.
Production
Live traffic with full observability dashboards (LangSmith or Helicone) handed to your team. 30-day post-launch window for prompt and flow adjustments is included.
Optional retainer. About 70% of our voice clients continue on a monthly retainer for ops, new intents, and prompt tuning. Optional — if you have an internal team ready to take over, we hand it off clean.
Vertical expertise, not a template.
Every industry has its own call pattern, compliance profile, and failure modes. We tune to yours.
Voice agent questions we answer on every discovery call.
How long does it take to build a production AI voice agent?
What's the realistic per-call cost?
Can your voice agents pass for human?
Do you handle HIPAA, GDPR, and other compliance?
Can the voice agent integrate with our existing CRM?
What happens when the AI doesn't understand?
Do we own the code and infrastructure?
Can you work alongside our internal dev team?
Ready to ship a voice agent that actually works?
One 20-minute call. No slides. We'll tell you if your use case is realistic, which platform fits your economics, and a ballpark number. If we're not a fit, we'll refer you to someone who is.