AI Voice Agents
Custom AI voice agents that pick up inbound calls, run outbound campaigns, book appointments straight into your calendar, and hand the hot ones to a human. Built on VAPI and Twilio, deployed to your infrastructure, wired into your CRM. Australian phone numbers, Australian voice, on production infrastructure.
Four pieces running in real time over a phone line. Speech-to-text turns the caller's voice into tokens. A large language model reasons about what they want and picks a reply. Text-to-speech turns that reply back into natural voice. A telephony layer (Twilio, for Australian numbers) carries all of it over the phone network. The whole loop lands in under a second, which is what makes the conversation feel human instead of robotic.
We use VAPI as the orchestrator because it handles the hard parts that otherwise eat weeks of engineering: interruption handling, endpointing, turn-taking, barge-in, noise handling, latency tuning. We use Twilio for Australian phone numbers and SIP trunking. On top of that we build the prompt, the call flow, the tool calls, the CRM and calendar integrations, the escalation rules, and the audit trail. That is the work that makes an agent yours, not a generic receptionist.
Most Australian businesses hit the same pattern: the cost of a missed call is bigger than the cost of running an agent. A plumber missing five calls a week at A$800 average job value loses around A$200,000 a year. A clinic missing fifteen calls a week at A$180 per appointment loses around A$140,000 a year. A voice agent running 24/7 at a few hundred dollars a month pays itself back on the first recovered call.
Want the technical build walkthrough? Read AI Voice Agents with VAPI and Twilio: The Build Playbook on Insights.
Every business says it wants AI. The ones that get ROI fast pick a call type that happens constantly and is currently handled badly.
Answer every inbound call, business hours or 2am Sunday. Qualify, answer FAQs, book appointments, take messages. Zero missed calls.
Activates outside business hours. Captures intent, urgency, and contact details. High-value leads get escalated by SMS to the on-call person in seconds.
Checks real calendar availability, offers slots, confirms, writes the event, sends SMS and email confirmation. Cancellations and reschedules handled the same way.
Agent calls warm leads from your CRM, qualifies against your BANT or MEDDIC criteria, books qualified ones into the sales calendar. Unqualified ones are dispositioned cleanly.
24 hours before the booking the agent calls, confirms attendance, offers rescheduling if needed. Written back to the CRM. Cuts no-shows by the margin your industry normally sees from reminders.
For overdue invoices, the agent calls politely, confirms identity, offers payment options, books a callback or completes payment via secure link by SMS. Tracked and audited.
First-line support for repetitive questions. Complex issues are transferred to a human with a one-sentence handoff summary so the human picks up in context.
Dormant customers, expired quotes, abandoned bookings. The agent calls, opens the conversation, books a human follow-up for anyone who bites.
Post-service NPS or CSAT calls. Structured responses captured, freeform comments transcribed, summaries written back to your dashboard.
Start here
from A$5,000
2-week diagnostic. Shadow a day of live calls, map the call types that happen most and cost you most, choose one or two for v1, produce a VAPI + Twilio architecture brief with a realistic cost model per minute.
Most common
from A$15,000
3 to 4 weeks end-to-end. One production voice agent (inbound or outbound) with Australian phone number, CRM and calendar integration, human escalation, transcripts, cost reporting, and a 30-day hypercare window.
Ongoing
from A$2,000/mo
Ongoing operation. Call-quality review, prompt tuning, failure handling, monthly cost and conversion reporting, new intent additions. Twilio and VAPI minutes billed at cost, no markup.
Week 01
Shadow live calls. Pick the first agent. Write the prompt. Design the call flow, the tool calls, the escalation rules. Agree the voice, the brand tone, the Australian phone number.
Week 02
Wire VAPI and Twilio. Connect the CRM and calendar. Build the handoff to human. Instrument transcripts and cost tracking. First internal calls happen here.
Week 03
Run adversarial calls: angry callers, accents, noisy backgrounds, edge questions, off-topic attempts. Tune the prompt. Harden escalation. Pilot with a small share of real traffic.
Week 04
Route production traffic. Daily review in week one, weekly after. Handover the runbook and the dashboards. 30 days of hypercare included. After that, it is yours or ours to operate.
Software that answers or makes phone calls in natural speech. ASR turns voice into text, an LLM reasons and picks a reply, TTS turns the reply back into voice, all in real time over the phone network. Built well, callers often cannot tell they are not speaking to a human.
VAPI handles the real-time voice loop, turn-taking, interruption, latency tuning, with sub-second end-to-end. Twilio provides Australian numbers and SIP. Together they remove about 80% of the engineering a voice agent needs. The remaining 20% (prompt, tools, CRM, governance) is the actual build.
Yes. Calendly, Google Calendar, Outlook / Microsoft 365, and most booking systems. Real availability, offered slots, confirmation, SMS and email reminders. Multi-resource and buffer-time handling for clinics and trades.
Per-minute dominated. Twilio AU inbound around A$0.02-0.04/min, VAPI around US$0.05-0.10/min. A 3-minute call lands at A$0.20-0.40 all-in. Against the revenue of a single recovered missed booking, the math ends the conversation.
Both, eventually. Most engagements start with one direction (usually inbound) and add the other once the first is proven in production. Nothing in the stack limits either.
Warm transfer is table stakes. Escalation rules (frustrated caller, explicit request, out-of-scope, high-value lead) route the live call via Twilio to your on-duty staff with a one-sentence handoff summary.
3 to 4 weeks for a well-scoped inbound or outbound agent. Complex multi-intent or regulated industries (clinical, legal, financial) run 6 to 8 weeks.
Clinics (dental, physio, GP), trades (plumbing, electrical, HVAC), real estate, legal, e-commerce support, professional services. Common pattern: high missed-call cost and high repetition, exactly where voice agents pay back fastest.
Technical walkthroughs and architecture pieces from the voice-agent engagements we run.
How to build production AI voice agents for Australian businesses on VAPI and Twilio. Architecture, cost model, inbound and outbound patterns, governance, from an operator who ships them.
Read analysisHow we shipped 55+ autonomous agents at 300% ROI and 35% cost reduction. Phase-by-phase playbook from an operator, the unsexy moves the 5% that ship actually do.
Read analysis80% of AI projects fail to deliver value and 42% show zero ROI. Here are the honest unit economics behind the 300% ROI outcome, what actually pays back, and how to build a believable business case.
Read analysis30-minute call. Bring your call data if you have it, volumes per hour, missed-call rate, average job or booking value. We'll model the payback and sketch the shortest path to a shipped, Australian-number, CRM-integrated voice agent.