Voice agents

A voice agent is an app people talk to out loud: a receptionist on your site, a talking helper inside your app, or an assistant that answers a phone number. Ask for one in plain words and the Voice agent skill takes over. For an agent people type to, see Build an AI agent. To talk to Alpha itself instead of typing, use dictation. Alpha will:

1. Ask two or three questions in one card: the channel, the job, and the languages and voice.
2. Ask for the model provider’s key with a secret request card, and for Twilio with a Connect card if you want phone calls or texts.
3. Build a server that holds the key, a page with a start button and a live transcript, and the tools the agent calls mid-conversation.
4. Test every layer it can reach without a microphone, then tell you two or three things to say to it.

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Choose a channel

The channel decides what you need to have ready. The browser is the default, and it’s the one channel you can try in the session straight away. When phone calls are part of the job, the agent builds and tests the browser version while Twilio is still being connected.

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Answer the setup card

The agent asks only what your message left open, in one question card. Anything you skip gets a sensible default, which the agent names in its reply. Every conversation keeps a transcript whatever you answer: who spoke, what they said, when, and which tools ran. Recording audio is separate and happens only if you say yes.

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Add the key and connect Twilio

The provider’s key stays on your app’s server. The browser gets a token from it that expires within minutes, so the key never reaches a visitor’s device. The agent asks for what it needs with cards in the transcript, so you never paste a key into a message. The agent doesn’t wait for Twilio. It builds and tests the browser version, says what it asked for, and ends its turn. Click Tell the agent to continue once you’re connected, and it adds the phone side. Your app reaches Twilio through your connections, so it holds no Twilio credentials of its own.

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Try it yourself

The machine has no microphone, so you are the one who holds the first conversation. When the build is done, the agent tells you two or three things to say. A real phone number needs a published app. The Preview’s address works only while the session’s machine is awake, and a machine goes to sleep once no Alpha page of yours has been on screen for about 30 minutes. A call to a sleeping machine doesn’t wake it, so the Preview’s address is good only for a test call while you’re there. Publish first, then the agent points the number’s voice webhook at the published address through Twilio, or gives you the address to paste into the Twilio console. The webhook’s address includes a random secret, which is what keeps strangers off it, so don’t share it. With phone calls, the app also gets a calls page: each call’s number, time, duration and how it ended, its transcript, and its recording when recording is on. It shows people’s numbers and words, so it sits behind your app’s sign-in. Recordings and transcripts are kept for 30 days unless you tell the agent otherwise, and are deleted together.

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Pick a runtime

The agent builds on a speech-to-speech realtime model unless you ask otherwise. One model hears and speaks, so replies start within a few hundred milliseconds and callers can interrupt it. Name a provider in your message to choose one. Model names change several times a year. The agent checks the provider’s current list before it picks one and keeps the name in one setting, so changing it later is a one-line edit.

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What does it cost, and how does Alpha check it?

Voice is billed per minute of audio by the provider, on your key. Those charges go to your provider account and don’t appear on Alpha’s usage dashboard, which counts the agent’s own work. Twilio bills numbers, calls and texts to your Twilio account. Before it hands over, the agent tests every layer below the microphone and names any check it couldn’t run, with the reason. The hand-over names the provider and model and why it chose them, reminds you that audio is billed per minute on your key, and says what each secret and connection is for.

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Is this the same as dictation?

No. Dictation is the microphone in your composer: it turns up to 2 minutes of your speech into a message for Alpha’s agent. A voice agent is an app you build, which other people talk to.

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Next steps