Utterance Streaming Event

{
  "message_type": "conversation",
  "event_type": "conversation.utterance.streaming",
  "seq": 500,
  "conversation_id": "your-conversation-id",
  "inference_id": "550e8400-e29b-41d4-a716-446655440000",
  "turn_idx": 7,
  "properties": {
    "role": "replica",
    "speech": "Here is everything said so far in this turn.",
    "content_index": 3,
    "final": false,
    "is_interrupted": false
  }
}

Outbound: Tavus sends each streaming chunk so you can show what is being said in real time as the accumulated text grows during the turn.

Contrast with conversation.utterance, which delivers the full turn text at once rather than streaming chunks.

message_type

string

conversation for conversation-layer app messages.

Example:

"conversation"

event_type

string

conversation.utterance.streaming.

Example:

"conversation.utterance.streaming"

timestamp

number

Unix timestamp (seconds since epoch) indicating when this event was created. Use this to build timestamped transcripts or reconstruct the timeline of a conversation.

Example:

1746000000.123

seq

integer

Monotonic per event; a higher seq was emitted later. Use with turn_idx as in Event ordering and turn tracking.

Example:

42

conversation_id

string

The unique identifier for the conversation.

Example:

"c123456"

inference_id

string

A unique identifier for the replica's current inference turn. Can be used to correlate with other events such as conversation.utterance and conversation.replica.started_speaking.

Example:

"83294d9f-8306-491b-a284-791f56c8383f"

turn_idx

integer

Turn index; increments when conversation.respond is processed. Groups utterances, tool calls, and speaking-state events for the same turn. See Event ordering and turn tracking.

Example:

3

properties

object

Replica and user streaming share this shape; is_interrupted appears on replica messages when relevant.

Show child attributes

Utterance Event Tool Call Event

⌘I

Documentation Index

Outbound: Tavus sends each streaming chunk so you can show what is being said in real time as the accumulated text grows during the turn.