Retell AI Developer — AI Voice Agents for Inbound & Outbound Calls
AI voice agents that answer and make calls, 24/7 — in a natural human voice.
Phones still drive real-world business, but answering them doesn't scale and every missed call is lost revenue. I build production AI voice agents — on Retell AI (and Vapi, Bland or Synthflow where they fit) — that answer and make calls in a natural voice, understand the caller, and complete the task: booking an appointment, qualifying a lead, answering FAQs or following up.
The difference between a demo and a reliable agent is the engineering around it: a tight script for your exact use case, custom function (tool) calling for live calendar and CRM lookups mid-call, guardrails, and a clean handoff to a human. I wire the whole flow together with n8n or Make.com and the tools you already use, then tune it against real calls. When a build needs lower-level control, I work directly with the voice layer (ElevenLabs, Deepgram) and the telephony (Twilio numbers, SIP trunking, LiveKit) — not just the managed platform.
I've shipped this in production — including an after-hours AI receptionist for a dental clinic that triages emergencies and books appointments 24/7 in English and Spanish.
How I deliver ai voice agents
24/7 inbound answering
An AI receptionist that answers every call, handles FAQs and books appointments — no missed calls, no hold music.
Outbound at scale
Speed-to-lead follow-up, appointment setting and database reactivation with a natural AI voice.
Live CRM & calendar integration
Custom function calling so the agent checks availability and reads or updates records mid-call, via n8n or Make.com.
Guardrails & human handoff
Compliance-aware call flows with a clean escalation to a human whenever the call needs one.
AI Voice Agents — FAQ
What does a Retell AI developer do?
A Retell AI developer designs, builds and integrates AI voice agents — writing the call script and prompt, setting up custom functions so the agent can act (book, look up, update), wiring it to your calendar, CRM and automations, and tuning it on real calls so it sounds natural and performs reliably in production.
Can the voice agent book appointments and update my CRM?
Yes. Using custom function (tool) calling, the agent checks live calendar availability and reads or writes records — for example in Airtable or your CRM — during the call, wired through n8n or Make.com.
Inbound, outbound, or both?
Both. Inbound agents answer every call 24/7 (an AI receptionist); outbound agents run follow-up, appointment-setting and reactivation campaigns at scale. Many clients use both.
Which platform do you build on — Retell, Vapi, Bland or Synthflow?
I build primarily on Retell AI for natural, reliable production agents, and on Vapi, Bland or Synthflow when the use case fits better. I recommend the right one for your needs, not a fixed preference.
Can the agent handle more than one language?
Yes — a single agent can handle multiple languages (for example English and Spanish), as in the after-hours dental clinic receptionist I built.
Is outbound AI calling compliant?
It can be, done responsibly — honouring consent and do-not-call rules, being transparent that it's an AI assistant, and handing off to a human appropriately. I build outbound agents with those guardrails in place.
Do you handle the telephony and SIP setup?
Yes — I set up the full telephony layer, including Twilio numbers and SIP trunking where you need it, plus lower-level voice tooling (ElevenLabs, Deepgram, LiveKit), so your AI voice agent connects cleanly to your phone system and carriers.
Can you integrate the voice agent with GoHighLevel?
Yes — I connect AI voice agents to GoHighLevel for speed-to-lead calling, appointment booking and pipeline updates, so a call instantly creates or updates the contact and triggers the right workflow.
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Need a ai voice agents expert?
Tell me what you're building and I'll reply within 24 hours with a clear plan and quote. Prefer to chat? Message me on WhatsApp.