Struct ToolSpan 

pub struct ToolSpan {
    pub id: String,
    pub name: String,
    pub started_at: SystemTime,
    pub duration_ms: Option<u64>,
    pub sidechain: bool,
    pub error: bool,
    pub kind: SpanKind,
}

One span of an agent trace: a tool call, an inference, or a turn.

Every harness writes the same shape in its own vocabulary — Claude pairs a tool_use block with a tool_result block by tool_use_id, Codex pairs a function_call with a function_call_output by call_id — and both stamp each line with a timestamp. That is a span: a name, a start and a duration. Only the call’s metadata is kept; arguments and output are never read.

The name predates kind: the type carried only tool calls until 0.3.1 and is kept for the sake of the published API.

Fields

id: String

The harness’s own call id, so a span survives across refreshes. For inference and turn spans, a counter the parser assigns.

name: String

Tool name as the harness reports it (Bash, exec_command, …), or inference / turn.

started_at: SystemTime

duration_ms: Option<u64>

Wall-clock duration, or None while the call is still in flight.

sidechain: bool

The call was issued by a subagent (Claude’s isSidechain).

error: bool

The harness reported the result as an error.

kind: SpanKind

Absent in snapshots written before 0.3.1, which held tool calls only.

Implementations

impl ToolSpan

pub fn is_open(&self) -> bool

pub fn elapsed_ms(&self, now: SystemTime) -> u64

Duration if closed, otherwise how long it has been running as of now.

pub fn ended_at(&self, now: SystemTime) -> SystemTime

Trait Implementations

impl Clone for ToolSpan

fn clone(&self) -> ToolSpan

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ToolSpan

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ToolSpan

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for ToolSpan

fn eq(&self, other: &ToolSpan) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for ToolSpan

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ToolSpan