Your first AI call

Before you begin

You need:

A Fonoster account. Sign up at app.fonoster.ai, or use the dashboard of your own Fonoster install.

A microphone and speakers (or a headset).

For the SDK or the CLI: Node.js 22 or later.

Calls from the browser need the dashboard on HTTPS or localhost. Fonoster Cloud is served over HTTPS. On your own install, open the dashboard at localhost on the machine that runs it.

Make the call

Create an Autopilot agent

An Autopilot agent is an AI that Fonoster runs for you. You give it a prompt, a voice and a language model. You don’t run a server.

Dashboard
SDK
CLI

Sign in to the dashboard and go to Autopilot.
Choose New agent.
Pick the Receptionist template.
Name it Front desk and keep the language English (US).
Choose Create agent.

The dashboard opens your new agent on the Configure tab. The template wrote the prompt and the greeting for you, and picked a matching voice and transcriber.

In the dashboard, go to API keys and create a key. Copy the key ID and the secret. You also need your workspace’s access key ID, which starts with WO.Install the SDK:

npm install @fonoster/sdk

Save this as create-agent.js. It signs in with your API key and creates an agent with a short receptionist prompt:

create-agent.js

const SDK = require("@fonoster/sdk");

async function main() {
  const client = new SDK.Client({
    accessKeyId: "WO7d2kq9x4m1c8b3n6p0r5t2v9y4z7a1e3"
  });
  await client.loginWithApiKey(
    process.env.FONOSTER_API_KEY,
    process.env.FONOSTER_API_SECRET
  );

  const apps = new SDK.Applications(client);
  const { ref } = await apps.createApplication({
    name: "Front desk",
    type: "AUTOPILOT",
    speech: {
      voice: "deepgram/aura-2-thalia-en",
      language: "en-US",
      sttModel: "deepgram/nova-3"
    },
    intelligence: {
      config: {
        conversationSettings: {
          firstMessage: "Hi, thanks for calling. How can I help you today?",
          systemPrompt:
            "You are the receptionist for our company. Answer in one or two short sentences. Ask one question at a time.",
          goodbyeMessage: "Thanks for calling. Have a great day!",
          systemErrorMessage:
            "Sorry, something went wrong on our side. Please call again in a few minutes."
        },
        languageModel: {
          model: "openai/gpt-4o-mini"
        }
      }
    }
  });

  console.log(`Agent created: ${ref}`);
}

main().catch(console.error);

Run it with your key:

FONOSTER_API_KEY=APk3n8q2w7e5r1t9y4u6i0o3p8a2s5d7f1 \
FONOSTER_API_SECRET=<your secret> \
node create-agent.js

It prints the agent’s ref:

Agent created: 6c1e2f4a-8b3d-4e7a-9f10-2d5c7b9e4a31

In the dashboard, go to API keys and create a key. Copy the key ID and the secret.Install the fonoster CLI and log in to your workspace. It asks for the endpoint (keep api.fonoster.ai for Fonoster Cloud), the key ID and the secret:

npm install -g @fonoster/ctl
fonoster workspaces:login

Save the agent as agent.yaml. It holds the agent’s messages and its language model:

agent.yaml

conversationSettings:
  firstMessage: "Hi, thanks for calling. How can I help you today?"
  systemPrompt: |
    You are the receptionist for our company.
    Answer in one or two short sentences. Ask one question at a time.
  goodbyeMessage: "Thanks for calling. Have a great day!"
  systemErrorMessage: "Sorry, something went wrong on our side. Please call again in a few minutes."
languageModel:
  model: openai/gpt-4o-mini

Create the agent with a voice, a language and a transcriber:

fonoster applications:create --name "Front desk" --agent agent.yaml \
  --voice deepgram/aura-2-thalia-en --language en-US --stt-model deepgram/nova-3

It prints the agent’s ref:

Application created: 6c1e2f4a-8b3d-4e7a-9f10-2d5c7b9e4a31

You have an agent named Front desk. It shows up under Autopilot in the dashboard.

Talk to it from your browser

In the dashboard, go to Autopilot and open Front desk. Choose Talk to agent, then Call. Allow the microphone when the browser asks.

The Talk to Front desk panel in the dashboard: Talk in the browser with a Call button, and Call this number saying no phone number is linked yet, with a Go to Numbers button.

The panel shows Connected and a call timer. The agent greets you: “Hi, thanks for calling. How can I help you today?” Ask it something, and it answers in a sentence or two.Choose Hang up when you’re done. Closing the panel also hangs up.

The call reaches the saved version of the agent. If you edit the agent, choose Save before you call again.

See the call

Go to Calls. Your browser call is at the top of the list. Open it to read the transcript.

You made your first AI call.

Give your agent a phone number

To let people call your agent from a phone, link a number to it. The fastest way is a Twilio number: Link a Twilio number walks you through it. You can also bring any carrier with a SIP trunk.

Once the number is in your workspace, go to Numbers and open it. Under When this number is called, send it to, choose Autopilot agent, then Front desk. The Talk to agent panel then lists the number under Call this number.

Next steps

Build an Autopilot agent

Write the prompt, pick the voice and model, and set how long calls last.

Give your agent tools

Let it hang up, transfer to a person, or call your API.

How Fonoster works

Learn how workspaces, numbers and applications fit together.

Build a stream

Run your own agent logic on your own server instead.

Get started

Autopilot

Streams

Telephony

Observe

Workspace

Reference

Self-hosting

Private regions

Hacking Fonoster

Your first AI call

Before you begin

Make the call

Give your agent a phone number

Next steps

Build an Autopilot agent

Give your agent tools

How Fonoster works

Build a stream

​Before you begin

​Make the call

​Give your agent a phone number

​Next steps

Build an Autopilot agent

Give your agent tools

How Fonoster works

Build a stream

Before you begin

Make the call

Give your agent a phone number

Next steps