audio
An audio response event. The payload’s state field selects the shape: start announces a messageID, content carries the audio in content with its encoding, and end carries the state alone.
speak
A spoken response for voice channels, carrying the message text and optionally a synthesized audio source and voice name.
stream
An audio stream event. The payload carries the source in src, a token, and an action of LOOP, PLAY, PAUSE, or END; title, description, iconImage, backgroundImage, and loop are optional.
dtmf
Configures keypad (DTMF) input collection on a call: whether it is enabled, the timeout, the ending delimiter, and the digit cap.
call-forward
Signals that the call is being forwarded. The payload always carries the destination in address and its kind in addressType; a phone forward may also carry an extension and a callerIDPassthrough flag. See the call forward step for configuration.