Struct Span 

pub struct Span {

    pub run_id: Uuid,
    pub parent_run_id: Option<Uuid>,
    pub trace_id: Uuid,
    pub kind: SpanKind,
    pub name: String,
    pub started_at: SystemTime,
    pub ended_at: Option<SystemTime>,
    pub level: ObservationLevel,
    pub status_message: Option<String>,
    pub input: Option<Value>,
    pub output: Option<Value>,
    pub session_id: Option<String>,
    pub user_id: Option<String>,
    pub tags: Vec<String>,
    pub metadata: HashMap<String, Value>,
    pub generation: Option<Generation>,
}

One node in the trace tree.

Fields

run_id: Uuid

This observation’s id.

parent_run_id: Option<Uuid>

Parent observation id, when nested.

trace_id: Uuid

Root run_id of the trace this span belongs to.

kind: SpanKind

Observation type.

name: String

Friendly name (e.g. “openai.gpt-4o”, “search_tool”, “agent_node”).

started_at: SystemTime

Wall-clock start.

ended_at: Option<SystemTime>

Wall-clock end (None until span closes).

level: ObservationLevel

Severity.

status_message: Option<String>

Set when level == Warning or Error.

input: Option<Value>

Input payload (Value to be backend-agnostic).

output: Option<Value>

Output payload.

session_id: Option<String>

Set only on the trace root.

user_id: Option<String>

Set only on the trace root.

tags: Vec<String>

Set only on the trace root.

metadata: HashMap<String, Value>

Free-form metadata (excluding well-known fields above).

generation: Option<Generation>

Some iff kind == Generation.

Trait Implementations

impl Clone for Span

fn clone(&self) -> Span

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Span

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Span

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Span

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

where __S: Serializer,

Serialize this value into the given Serde serializer.