Struct OutputMessageDeltaData 

pub struct OutputMessageDeltaData {
    pub turn_id: TurnId,
    pub message_id: MessageId,
    pub delta: String,
    pub accumulated: String,
    pub phase: Option<ExecutionPhase>,
}

Data for output.message.delta event

Incremental text update during LLM generation. Events are batched (~100ms) to reduce volume while providing real-time feedback.

Fields

turn_id: TurnId

Turn ID this delta belongs to

message_id: MessageId

Stable public ID for this assistant message across its streaming lifecycle. This is the same identifier as OutputMessageCompletedData.message.id.

delta: String

The new text chunk

accumulated: String

Accumulated text so far

phase: Option<ExecutionPhase>

Best-effort streamed phase hint (EVE-774).

None means “not yet classified — treat as ordinary assistant text”, NEVER “thinking”. Refinement is monotonic: once a stream reveals a native phase (Commentary or FinalAnswer) it stays fixed for the rest of the message — it never flip-flops and never reverts to None (see ExecutionPhase::refine_streamed_hint). Providers without native mid-stream phase (Anthropic, Gemini, …) leave this None until completion. The authoritative classification remains the completed Message.phase. See specs/events.md.

Trait Implementations

impl Clone for OutputMessageDeltaData

fn clone(&self) -> OutputMessageDeltaData

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for OutputMessageDeltaData

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for OutputMessageDeltaData

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<OutputMessageDeltaData> for EventData

fn from(data: OutputMessageDeltaData) -> Self

Converts to this type from the input type.

impl Serialize for OutputMessageDeltaData

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.