Reference

VoiceML nouns

Nouns are the elements nested inside a verb that name what it acts on — the number a <Dial> calls, the WebSocket a <Stream> forks to, the room a call joins.

Noun Used inside What it does Status
<Number> <Dial> Dial a phone number. Available
<Sip> <Dial>, <Refer> Dial a SIP URI directly, or name the transfer target of a <Refer>. Available
<Client> <Dial> Dial a registered SIP client by identity. Available
<Conference> <Dial> Join the call into a named conference room. Available
<Queue> <Dial> Bridge the caller (typically an agent) to the front-of-queue waiting caller. Available
<Application> <Dial> Hand the call leg to a saved Application's voice URL. Available
<Sim> <Dial> Mobile-SIM dialing. Not supported. No
<Stream> <Connect>, <Start>, <Stop> Fork the call audio to your WebSocket server. Available
<ConversationRelay> <Connect> Bridge the call to your AI voice agent over a JSON WebSocket — the platform runs speech recognition and synthesis in-line. Available
<Transcription> <Start>, <Stop> Live transcription of the call, delivered to your webhook while the document keeps executing. Available
<Siprec> <Start>, <Stop> Stream both legs of the call to your session-recording server over the SIPREC standard (RFC 7866). Available
<Parameter> <Siprec> A name/value pair passed through to the parent element's session. Available
<Identity> <Client> The client identity to dial, as a nested element. Available
<Prompt> <Pay> Customise a built-in <Pay> prompt for a specific capture step. Available