Enum StreamChunk 

pub enum StreamChunk {
    TextDelta(String),
    ThinkingDelta(String),
    ToolCallReady(ToolCall),
    ToolCalls(Vec<ToolCall>),
    Done(TokenUsage),
    NetworkError(String),
}

A streaming chunk from the LLM.

Variants

TextDelta(String)

A text delta (partial content).

ThinkingDelta(String)

A thinking/reasoning delta from native API (Anthropic extended thinking, OpenAI reasoning).

ToolCallReady(ToolCall)

A single tool call whose arguments finished streaming.

Emitted by providers that support per-block completion events (Anthropic content_block_stop). Enables eager execution of read-only tools while subsequent tool calls are still being streamed.

Providers that don’t support per-block events (OpenAI, Gemini) never emit this — they only emit ToolCalls at stream end.

ToolCalls(Vec<ToolCall>)

All tool calls from the response (batch, emitted at stream end).

For Anthropic, this only contains tool calls NOT already emitted via ToolCallReady. For other providers, this contains all tool calls.

Done(TokenUsage)

Stream finished with usage info.

NetworkError(String)

The underlying HTTP connection was dropped before the stream completed.

Distinct from Done (clean finish) and user-initiated cancellation (Ctrl+C). The partial response MUST be discarded — it is incomplete and storing it would corrupt the session history on resume.

Trait Implementations

impl Clone for StreamChunk

fn clone(&self) -> StreamChunk

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StreamChunk

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

Formats the value using the given formatter.