Enum StreamEvent 

pub enum StreamEvent {
    TextDelta(String),
    ToolCallStart {
        name: String,
        index: usize,
        id: Option<String>,
    },
    ToolCallDelta {
        index: usize,
        arguments_delta: String,
    },
    Usage {
        input_tokens: u64,
        output_tokens: u64,
    },
    Done {
        text: String,
        tool_calls: Vec<ToolCall>,
    },
}

Events emitted during a streaming inference response.

Variants

TextDelta(String)

Partial text token from the model.

ToolCallStart

A tool call is starting (name known, arguments pending).

Fields

name: String

index: usize

id: Option<String>

ToolCallDelta

Partial tool call arguments (JSON fragment).

Fields

index: usize

arguments_delta: String

Usage

Provider-reported cumulative token usage observed mid-stream.

Anthropic emits this twice: once in message_start with the finalized input_tokens (plus a stub output_tokens: 1), and again in message_delta at end of stream with the real output_tokens. Consumers should prefer per-field monotonicity (see StreamAccumulator) rather than overwriting blindly.

Fields

input_tokens: u64

output_tokens: u64

Done

Stream is complete. Contains the final aggregated result.

Fields

text: String

tool_calls: Vec<ToolCall>

Trait Implementations

impl Clone for StreamEvent

fn clone(&self) -> StreamEvent

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StreamEvent

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

Formats the value using the given formatter.