Struct Turn 

pub struct Turn {
    pub id: TurnId,
    pub input: TurnInput,
    pub metrics: TurnMetrics,
    pub cancel_token: CancellationToken,
}

Complete state of a single agent turn from input through metrics capture.

Created at the start of process_user_message, populated through the turn lifecycle, and consumed at the end for metrics emission and trace completion.

Ownership: Turn is stack-owned — created in begin_turn, passed through sub-methods by &mut Turn, and consumed in end_turn. It is never stored on the Agent struct.

Phase 1 scope: carries id, input, metrics, and cancel_token only.

Fields

id: TurnId

Monotonically increasing identifier for this turn within the conversation.

input: TurnInput

Resolved user input for this turn.

metrics: TurnMetrics

Per-turn metrics accumulated during the turn lifecycle.

cancel_token: CancellationToken

Per-turn cancellation token. Cancelled when the user aborts the turn or the agent shuts down. Created fresh in Turn::new so each turn has an independent token.

Implementations

impl Turn

pub fn new(id: TurnId, input: TurnInput) -> Self

Create a new turn with the given ID and input.

A fresh CancellationToken is created for each turn so that cancelling one turn does not affect subsequent turns.

Examples

let input = TurnInput::new("hello".to_owned(), vec![]);
let turn = Turn::new(TurnId(0), input);
assert_eq!(turn.id, TurnId(0));

pub fn id(&self) -> TurnId

Return the turn ID.

pub fn metrics_snapshot(&self) -> &TurnMetrics

Return an immutable reference to the turn metrics.

pub fn metrics_mut(&mut self) -> &mut TurnMetrics

Return a mutable reference to the turn metrics.