Enum TurnEvent 

pub enum TurnEvent {
    Chunk {
        delta: String,
    },
    Thinking {
        delta: String,
    },
    ToolCall {
        id: String,
        name: String,
        args: Value,
    },
    ToolResult {
        id: String,
        name: String,
        output: String,
    },
    Plan {
        entries: Vec<PlanEntry>,
    },
    ApprovalRequest {
        request_id: String,
        tool_name: String,
        arguments_summary: String,
        timeout_secs: u64,
    },
    HistoryTrimmed {
        dropped_messages: usize,
        kept_turns: usize,
        reason: String,
    },
    Usage {
        input_tokens: Option<u64>,
        cached_input_tokens: Option<u64>,
        output_tokens: Option<u64>,
        cost_usd: Option<f64>,
    },
}

Variants

Chunk

A text chunk from the LLM response (may arrive many times).

Fields

delta: String

Thinking

A reasoning/thinking chunk from a thinking model (may arrive many times).

Fields

delta: String

ToolCall

The agent is invoking a tool.

Fields

id: String

Stable correlation ID shared with the matching TurnEvent::ToolResult.

name: String

args: Value

ToolResult

A tool has returned a result.

Fields

id: String

Stable correlation ID shared with the originating TurnEvent::ToolCall.

name: String

output: String

Plan

Fields

entries: Vec<PlanEntry>

ApprovalRequest

Fields

request_id: String

Correlation ID. The matching response frame must echo it.

tool_name: String

arguments_summary: String

Human-readable, secret-redacted summary of the tool arguments. Synthesised by crate::approval::summarize_args; never the raw args value.

timeout_secs: u64

How long the channel will wait before auto-denying.

HistoryTrimmed

Older whole turns were dropped to fit either the context token budget or the configured message limit. Surfaces a user-visible “context was cut here” marker so trimming is never silent. Emitted whenever a trim occurs.

Fields

dropped_messages: usize

kept_turns: usize

reason: String

Usage

Per-LLM-call token usage and cost; a turn may emit several, one per model call. None means “unavailable for this call”, not zero.

Fields

input_tokens: Option<u64>

cached_input_tokens: Option<u64>

Tokens served from the provider’s prompt cache (e.g. Anthropic cache_read_input_tokens, OpenAI cached_tokens). These count toward the context window and must be added to input_tokens to get the true total context size.

output_tokens: Option<u64>

cost_usd: Option<f64>

Trait Implementations

impl Clone for TurnEvent

fn clone(&self) -> TurnEvent

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TurnEvent

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

Formats the value using the given formatter.