What’s under an AI voice agent? Twilio and programmable telephony
Many businesses believe that to have an AI agent on the phone they must change their number, their PBX, or their operator. The reality is simpler: programmable telephony allows your existing number to be answered by AI, and understanding that piece helps you make better purchasing decisions.
The short answer: yes, it’s possible. Twilio has a public API and an AI agent can connect to it today so your calls and WhatsApp conversations are handled and logged without manual work. At Veltim we design and implement this integration: the first call is free and the quote is fixed. The rest of the article explains how.
Twilio is the most widespread programmable communications platform: phone numbers, calls, SMS and WhatsApp managed programmatically. It is one of the usual building blocks on which AI voice agents are constructed.
What Twilio’s API enables
Its public API controls the entire call lifecycle: receiving it, answering with real-time audio, transferring it to a person, recording it with consent and hanging up while leaving a record. It also covers SMS and the WhatsApp API, with industry-standard documentation.
That the API is public and documented matters more than it seems: it means the integration does not depend on hacks or opaque connectors, but on an official contract that the platform itself maintains. The full reference is in the Twilio developer documentation.
How we solve it with Twilio
Veltim’s voice agent runs on this infrastructure: your number receives the call, the AI converses in real time, checks your calendar or your CRM during the conversation and, if necessary, transfers to your team with the context already collected. For the calling customer it is a normal call; the difference is that someone always answers.
The principle is always the same: the AI agent handles the conversation and Twilio just finds out. No scribbling on paper to pass information later, no leads lost between the phone and the CRM.
This integration performs best in any business that relies on the phone: clinics, restaurants, service providers and real estate agencies.
What you should know beforehand
Programmable telephony is billed by usage (numbers, minutes, messages): a high volume of calls has a variable cost that must be estimated in advance. In the quote we calculate it with your real volume so there are no surprises on the bill.
Let’s be clear: none of these points prevents the integration. They are design decisions we resolve before connecting anything, and that is why the quote we provide is fixed: the tool’s limits are already accounted for. The rule is design first and connect later: what records the agent creates, which ones it updates, and what always remains in the team’s hands.
Frequently asked questions
Can I keep my existing phone number?
Yes. The usual approach is to port or forward your current number so the agent can answer on it: your clients won’t notice any number change, only that someone always picks up.
Can AI calls be recorded?
Technically yes, and sometimes it is useful for quality and record-keeping, but in Spain it requires informing the caller. We configure it in compliance with the GDPR and advise you on the appropriate notice.
Do I have to change tools to work with Veltim?
No. The integration is built on what you already use: the advantage of tools with a public API like Twilio is precisely that they don’t force any migration.
Who implements this integration and how much does it cost?
It is designed and implemented by Veltim, an AI automation agency based in Madrid that works remotely across Spain. The price depends on your volume and what needs to be connected: in a free call we review your Twilio account and provide a fixed quote with specific timelines.
Twilio is a registered trademark of its owner. Veltim is not affiliated with or sponsored by the brand: this article describes a technical integration via its public API.
Do you use Twilio and want your calls and WhatsApp messages to be logged automatically? Tell us about your case and we’ll review it on your real account. You have the complete catalogue of tools we connect at integraciones, and you can also see how our voice agents and chatbots work or read client cases.
In short
Programmable telephony like Twilio lets an AI agent answer using your existing number, integrate in real time with calendars and CRMs, and keep full records without manual handoffs. The integration is built on documented APIs, billed by usage, and implemented by Veltim with a fixed quote after a free initial review.
Kevin Rojas — Fundador de Veltim. Programador e ingeniero de IA: agentes de voz, chatbots de WhatsApp e integraciones con CRM para negocios reales. LinkedIn · YouTube · Sobre Veltim
Contact: veltim.com · Phone: +34 623 05 08 56 · Madrid, Spain.