Voice

Voice tools let agents make and manage phone calls through Twilio integration.

voice_call

Places an outbound voice call on behalf of the user.

voice_call(
  phone_number: "+15551234567",
  name: "Acme Support",
  objective: "Ask about the status of order #12345"
)

Parameters

Parameter	Type	Required	Description
`phone_number`	string	yes	Phone number in E.164 format (e.g., `+15551234567`)
`name`	string	yes	Name of the person or company being called
`objective`	string	yes	The specific goal of the call
`initial_greeting`	string	no	Message spoken by the agent when the call connects
`hints`	string	no	Comma-separated words or phrases to improve speech recognition

send_dtmf

Sends DTMF (touch-tone) signals during an active call. Useful for navigating automated phone menus or entering PINs.

send_dtmf(digits: "1")

Parameters

Parameter	Type	Required	Description
`digits`	string	yes	DTMF digits to send (`0-9`, `*`, `#`)

hangup_call

Ends the active voice call.

hangup_call()

No parameters.

Requirements

Voice features require:

A Twilio account with a phone number
The following environment variables configured:

Variable	Description
`FRONA_VOICE_TWILIO_ACCOUNT_SID`	Your Twilio account SID
`FRONA_VOICE_TWILIO_AUTH_TOKEN`	Your Twilio auth token
`FRONA_VOICE_TWILIO_PHONE_NUMBER`	Your Twilio phone number (E.164 format)
`FRONA_VOICE_CALLBACK_BASE_URL`	Public URL for Twilio callbacks

Callback URL

Twilio needs a publicly accessible URL to send call events to. Set FRONA_VOICE_CALLBACK_BASE_URL to your public URL. This overrides FRONA_SERVER_BASE_URL for voice callbacks.

During development, you can use ngrok (included in the Docker Compose setup) to expose your local instance.

The Receptionist agent

The built-in Receptionist agent is pre-configured for voice calls. It has the voice tools enabled and system prompts designed for phone interactions. It reads your memory before making calls to understand context.

See Agent Types for more on the Receptionist.

Integration guide

For a complete setup walkthrough, see the Twilio Voice Integration guide.