AsyncAPI channel · Twilio · Twilio Real-Time WebSocket APIs

`conversation-relay`

Single ConversationRelay WebSocket session. All frames are JSON-encoded text frames carrying a `type` discriminator. The session begins with a `setup` message and continues with `prompt`, `dtmf`, `interrupt`, and `error` frames from Twilio. The customer server streams back `text` tokens, `play` media, `sendDigits` DTMF, `language` switches, and an `end` directive to terminate the session.

Open source AsyncAPI → All Twilio channels Twilio provider profile

Provider: Twilio AsyncAPI: v2.6.0 Spec: Twilio Real-Time WebSocket APIs Operations: 2 Messages: 10

Channel address

conversation-relay

Operations

publish

relaySendToTwilio

Frames sent FROM the customer server TO Twilio.

relayReceiveFromTwilio

Frames sent FROM Twilio TO the customer server.

Messages

text

Streams an individual TTS text token (or final token) to Twilio.

Content-Type: application/json

play

Requests Twilio to play an external media file to the caller.

Content-Type: application/json

sendDigits

Sends DTMF digits down the call leg.

Content-Type: application/json

language

Switches the TTS and/or STT language mid-session.

Content-Type: application/json

end

Ends the ConversationRelay session and hands the call back to TwiML.

Content-Type: application/json

setup

Sent immediately after the WebSocket connection establishes.

Content-Type: application/json

prompt

Transcribed caller speech, streamed as the caller talks.

Content-Type: application/json

dtmf

A DTMF key pressed by the caller.

Content-Type: application/json

interrupt

Caller speech interrupted in-progress TTS playback.

Content-Type: application/json

error

Session-level error reported by Twilio.

Content-Type: application/json

About AsyncAPI

The AsyncAPI specification describes event-driven APIs the way OpenAPI describes request/response APIs. A channel is the named pipe — a webhook URL, a Kafka topic, a WebSocket route, an MQTT subject — that producers and consumers publish or subscribe to. Each channel carries one or more messages with structured payloads, and an operation declares whether a given party sends or receives on that channel.

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