A Twilio AI voice agent you connect, not one you build

A Twilio AI voice agent starts with what Twilio provides: phone numbers, a web console, APIs and usage-based charges for call minutes. That is the telephone side of the job. The part that listens to a caller, understands the question and gives a correct answer is not in the box. You can build that part on top of Twilio, or you can connect an agent that already exists. This page is about the second route, written for someone who will open the Twilio Console in another tab while reading.

It helps to be clear about what a build involves. You write and host the service that the number's voice webhook points to. You connect speech recognition, a language model and speech synthesis, and you keep the delay between them short enough for a natural conversation. You add a way for the model to find answers in your own documents instead of guessing. You handle a caller who talks over the reply, you write the transfer logic, and you decide what happens when nobody picks up. Each of these parts is documented and a developer can build them. After launch, someone also has to run the service and keep it up to date.

Connecting Asyntai replaces all of that with a form. On the Phone Calls page you paste the Account SID and Auth Token from the home page of the Twilio Console and press Connect. Asyntai checks the values with Twilio and lists the voice-capable numbers on your account. Press Import next to a number, and Asyntai sets that number's voice webhook. The next call to it reaches the agent. There is no handler to write, no server to host and no number to edit by hand. If you rotate the Auth Token, you connect again with the new one.

On the call itself, the agent first says that it is an AI assistant, and then says the greeting you wrote on the Voice Agent page. After that, the caller simply talks. The reply comes within a second or two, and the caller can interrupt the agent whenever they like. The answers come from your Asyntai knowledge base: your website, read page by page, the PDF files and text you upload, and the AI Instructions you write in plain English. The agent does not invent prices or policies. When a question is not covered, it offers a callback request. If your own system has an API, Custom Tools let the agent fetch live data during the call, such as the state of an account, on the Standard plan and higher.

A Twilio AI receptionist also needs a clear way to reach a person. Every imported number has a field called Transfer to a person, which takes an office line or a mobile in international format. Transfers need Escalate to Human to be on, and they happen only during its business hours. When a caller asks for a person, the agent says it is putting them through, and Twilio places the transfer as a normal outgoing call on your account. The phone that rings shows the caller's own number. If nobody answers within 20 seconds, or the line is busy, the caller comes back to the agent, which apologizes and takes a callback request. Outside your hours, a callback request is the route: the agent asks for a name and a number, repeats the digits one by one, waits for the caller to confirm them, and sends the request to your escalation email. If you leave the transfer field empty, the agent always takes a callback request.

The requirements are short. You need an Asyntai plan at Standard or above, and an upgraded Twilio account with at least one voice-capable number, because a trial account cannot be used. Twilio may ask for business verification before you can buy a number, and that check runs on Twilio's timetable, so start it early. Twilio bills you for the numbers and the call minutes; its current rates are on the Twilio voice pricing page. Asyntai bills the plan. Standard costs $139 a month and includes 200 voice minutes and 5 calls at the same time. Pro costs $449 a month and includes 1,500 voice minutes and 10 calls at the same time. Each answer on a call also counts as one AI reply on the plan. When every line is in use, a new caller hears that the lines are busy. When the month's minutes are used up, calls are declined with a short message until the minutes reset. For more minutes than Pro includes, write to [email protected].

You stay in control of each number. Switch a number off and calls to it are declined with a short message, while the import stays in place for later. Remove it and Asyntai clears the voice webhook, so you can use the number for something else in Twilio. Disconnect the whole account and every imported number is released. If the number your customers know belongs to another provider, you can forward calls from it to the Twilio number, for example when nobody answers or after hours, with the call forwarding most phone providers offer. Or you can publish the Twilio number as the line.

Two more things come with the agent. Every call is stored as a conversation in your Asyntai dashboard, with the full transcript, and phone numbers or email addresses that callers give can be saved as leads when lead collection is on. The same agent can also add a voice button to the Asyntai chat widget on your website, so visitors can talk instead of type. It uses the same knowledge and the same minutes, and the transcript goes into the chat.

The best way to judge it is to hear it before you touch Twilio. Add your website, write a greeting, and make a free test call in the browser from the Voice Agent page. When the answers are right, connect the account and import one number. The Twilio voice setup guide shows each screen, including the transfer settings.