Struct Turn 

pub struct Turn {

    pub id: String,
    pub parent_id: Option<String>,
    pub group_id: Option<String>,
    pub role: Role,
    pub timestamp: String,
    pub text: String,
    pub thinking: Option<String>,
    pub tool_uses: Vec<ToolInvocation>,
    pub model: Option<String>,
    pub stop_reason: Option<String>,
    pub token_usage: Option<TokenUsage>,
    pub attributed_token_usage: Option<TokenUsage>,
    pub environment: Option<EnvironmentSnapshot>,
    pub delegations: Vec<DelegatedWork>,
    pub file_mutations: Vec<FileMutation>,
}

A single turn in a conversation, from any provider.

Fields

id: String

Unique identifier within the conversation.

parent_id: Option<String>

Parent turn ID (for branching conversations).

group_id: Option<String>

Identifier of the source accounting unit this turn belongs to — a message for Claude (message.id), a round for Codex (turn_id). A grouping key, not a turn identifier: when a provider derives several turns from one unit (Claude writes one JSONL line per content block; a Codex round emits several turns), every sibling turn carries the same value, and group-level accounting (token_usage) belongs to the group once (on its final turn).

role: Role

Who produced this turn.

timestamp: String

When this turn occurred (ISO 8601).

text: String

The visible text content (already collapsed from provider-specific formats).

thinking: Option<String>

Internal reasoning (chain-of-thought, thinking blocks).

tool_uses: Vec<ToolInvocation>

Tool invocations in this turn.

model: Option<String>

Model identifier (e.g. “claude-opus-4-6”, “gpt-4o”).

stop_reason: Option<String>

Why the turn ended (e.g. “end_turn”, “tool_use”, “max_tokens”).

token_usage: Option<TokenUsage>

Token usage for this turn. When this turn belongs to a group_id group, this is the whole message’s total, carried on the group’s final turn only (it always means “the total for a message”; summing over turns yields session totals).

attributed_token_usage: Option<TokenUsage>

This turn’s own attributed spend, when the source provides step-aligned data — the output tokens generated for this turn, distinct from Turn::token_usage (the whole message’s total). Populated where a provider streams per-step counts (Claude’s per-content-block cumulative usage, Codex’s per-step token_count deltas); absent where it can’t be attributed. Within a group_id group, Σ attributed_token_usage is the group’s attributed output; the unattributed remainder (prompt-side input/cache, inherently per-message) stays in token_usage on the group’s final turn. A separate field from token_usage precisely so the session-total sum is unaffected.

environment: Option<EnvironmentSnapshot>

Environment at time of this turn.

delegations: Vec<DelegatedWork>

Sub-agent work delegated from this turn.

file_mutations: Vec<FileMutation>

File mutations produced by this turn, with diffs pre-resolved by the provider’s to_view. Each entry projects to a sibling file.write artifact change in the derived step. When the mutation is attributable to a specific tool call, tool_id on the entry links back to that ToolInvocation::id.

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.