Provider-assigned event ID for idempotency.
Provider-assigned call ID.
Unix timestamp (ms).
Optional providerProvider namespace attached by stable carrier parsing.
Optional providerCreation request identity when distinct from the actual call leg.
The digit pressed by the caller.
Standard DTMF digits: '0'-'9', '*', '#'.
Extended DTMF (rarely supported): 'A'-'D'.
Optional durationHow long the key was pressed in milliseconds, when the message carries it.
Most messages omit it: Twilio's documented media-stream dtmf message
carries only the track and the digit, and Telnyx and Plivo webhook
payloads typically omit it.
DTMF (Dual-Tone Multi-Frequency) digit received during a call.
DTMF events do NOT trigger a call state transition -- the call remains in its current state (typically
listeningoractive). They are relayed as informational events so higher-level logic (e.g., IVR menus, PIN entry) can react to caller key-presses.Delivery paths
All three carriers have webhook and media-stream DTMF paths. A webhook occurrence identity and a media-stream sequence belong to their own delivery channels; hosts choose one input path for an IVR action.
Example