Enum StreamEvent 

pub enum StreamEvent {
    TextDelta {
        delta: String,
    },
    ThinkingDelta {
        delta: String,
    },
    ToolCall {
        id: String,
        name: String,
        arguments: Value,
    },
    Usage {
        total_tokens: u32,
        input_tokens: u32,
        output_tokens: u32,
        cache_read_input_tokens: u32,
        cache_creation_input_tokens: u32,
        cache_read_input_tokens_by_slot: Option<CacheReadBySlot>,
    },
    Done,
}

Stream event emitted by providers.

Variants

TextDelta

Fields

delta: String

ThinkingDelta

Fields

delta: String

ToolCall

Fields

id: String

name: String

arguments: Value

Usage

Token usage from the provider (e.g. OpenAI stream_options.include_usage).

Fields

total_tokens: u32

input_tokens: u32

Full prompt size: uncached input + cache reads + cache writes.

output_tokens: u32

cache_read_input_tokens: u32

Prompt tokens served from cache (billed ~0.1x). Subset of input_tokens.

cache_creation_input_tokens: u32

Prompt tokens written to cache (billed ~1.25x). Subset of input_tokens.

cache_read_input_tokens_by_slot: Option<CacheReadBySlot>

I1: pro-rata per-slot attribution of cache_read_input_tokens (Anthropic only). None when the provider doesn’t honor cache_control or when no breakpoints were placed. Estimated (Anthropic returns a single scalar) — see helper docs.

Done

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.