The phone line
underneath the agent.
A voice AI agent needs an actual phone number and call-routing infrastructure to be reachable by real customers. Twilio is the telephony layer we connect underneath voice orchestration platforms like Vapi — inbound numbers, outbound calling, call transfer to a human.
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Phone numbers,
real infrastructure.
Twilio provides the actual telephony — phone numbers, SIP trunking, call routing — that sits beneath the voice AI layer. A conversational agent still needs a real number customers can call or be called on, and real infrastructure for transferring a call to a human when the agent hands off.
We integrate it as the carrier layer under Vapi-orchestrated voice agents, handling the parts a customer actually dials.
Reliable calls,
clean handoffs.
The telephony layer has to be as reliable as the AI layer on top of it.
Inbound and outbound numbers configured for the specific workflow — support line, outbound campaign, or both.
Live transfer to a person when the agent's scope runs out, without the caller having to repeat themselves.
Call metadata and outcomes tracked, feeding the same observability as the rest of a voice AI deployment.
Where this fits
The telephony layer underneath our voice AI work.
Before you
book a call.
The questions we get asked most about Twilio and voice AI telephony — answered straight, no sales pitch.
Does a voice AI agent need Twilio specifically?
It needs some telephony provider to be reachable by real phone calls — Twilio is the one we default to for its reliability and the breadth of its routing and number options.
Can a call be transferred to a human mid-conversation?
Yes — that handoff is built in as a standard part of the deployment, with the human receiving call context rather than a cold transfer.
Does this work for both inbound and outbound calls?
Yes — Twilio handles both, and which direction (or both) a project needs depends on the use case.
Tell us what
you're trying to build.
Book a 30-minute call — or try our live voice demo to hear a real deployment first.