Struct Turn 

pub struct Turn {
    pub turn_id: TurnId,
    pub triggered_by: TurnTrigger,
    pub usage: Usage,
    pub input_messages: Vec<AgentMessage>,
    pub output_message: AgentMessage,
    pub tool_results: Vec<AgentMessage>,
    pub started_at: DateTime<Utc>,
    pub ended_at: DateTime<Utc>,
    pub request_payload: Option<AnnotatedRequestPayload>,
}

A materialized record of one LLM turn within a loop.

Each turn represents one LLM call-response cycle plus any tool executions that followed. Built by [SessionRecorder] from TurnStart/TurnEnd event pairs.

Message partitioning

• input_messages — user prompts, steering messages, and follow-ups injected at the start of this turn (between TurnStart and the assistant response).
• output_message — the assistant’s streamed response (from TurnEnd.message).
• tool_results — tool result messages executed this turn (from TurnEnd.tool_results). Empty when no tool calls were made (StopReason::Stop).

Fields

turn_id: TurnId

Identifies this turn: loop_id + turn_index.

triggered_by: TurnTrigger

What caused this turn to begin.

usage: Usage

Per-turn token usage (from TurnEnd.usage).

input_messages: Vec<AgentMessage>

Messages injected at the start of this turn (user prompts, steering messages, follow-ups). Empty for continuation turns that only have tool results from the prior turn feeding back in.

output_message: AgentMessage

The assistant message produced by the LLM this turn.

tool_results: Vec<AgentMessage>

Tool result messages from this turn. Empty when no tool calls were made.

started_at: DateTime<Utc>

Wall-clock time when this turn began (from TurnStart.timestamp).

ended_at: DateTime<Utc>

Wall-clock time when this turn completed (from TurnEnd.timestamp).

request_payload: Option<AnnotatedRequestPayload>

Fully-assembled LLM request payload captured from crate::AgentEvent::TurnRequest when crate::session::SessionRecorderConfig::capture_turn_requests is enabled. None when capture is off (default) or for sessions persisted before phi-core 0.9.0.

Added in phi-core 0.9.0. Serialization is skipped when None for back-compat (existing session JSON loads cleanly into 0.9.0 readers).

Implementations

impl Turn

pub fn index(&self) -> u32

The zero-based turn index within its loop.

pub fn duration(&self) -> Duration

Duration of this turn.

pub fn has_tool_calls(&self) -> bool

Whether this turn included tool calls.

pub fn all_messages(&self) -> Vec<&AgentMessage>

All messages in this turn in chronological order: input_messages, then output_message, then tool_results.

Trait Implementations

impl Clone for Turn

fn clone(&self) -> Turn

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Turn

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Turn

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Turn

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.