Struct ScalarFields 

#[non_exhaustive]
pub struct ScalarFields<'a> {
    pub kernel_id: &'a str,
    pub tool_name: &'a str,
    pub call_id: &'a str,
    pub skill_id: &'a str,
    pub model: &'a str,
    pub response_id: &'a str,
    pub previous_response_id: &'a str,
    pub dataset: &'a str,
    pub metric: &'a str,
    pub verdict: &'a str,
}

Per-variant scalar correlation fields surfaced as direct tracing attributes alongside the JSON event blob. See EventKind::scalar_fields.

Absent fields are represented as "" rather than Option<&str> because tracing 0.1’s static-field model requires every field at the call site to satisfy tracing::Value, which is not implemented for Option<T>.

Marked #[non_exhaustive] so future schema-additive releases can append new scalar correlators without a breaking change. Build a value via Default::default and field-update syntax (ScalarFields { tool_name, ..Default::default() }) rather than the full struct literal.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

kernel_id: &'a str

compose.* event kernel identifier.

tool_name: &'a str

tool.* and compose.retry_attempt target/tool name.

call_id: &'a str

tool.* stable correlation identifier.

skill_id: &'a str

compose.skill_resolved / compose.loop_iteration skill identifier.

model: &'a str

prompt.* model identifier.

response_id: &'a str

prompt.completed / response.* provider response identifier.

previous_response_id: &'a str

prompt.completed / response.turn_* chain ancestor — populated when the producer is on a stateful endpoint such as OpenAI’s Responses API where the current turn was created with previous_response_id.

dataset: &'a str

eval.report dataset / qrels label.

metric: &'a str

eval.report metric name.

verdict: &'a str

eval.report regression-gate verdict.

Trait Implementations

impl<'a> Clone for ScalarFields<'a>

fn clone(&self) -> ScalarFields<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for ScalarFields<'a>

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

Formats the value using the given formatter.

impl<'a> Default for ScalarFields<'a>

fn default() -> ScalarFields<'a>

Returns the “default value” for a type.

impl<'a> PartialEq for ScalarFields<'a>

fn eq(&self, other: &ScalarFields<'a>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a> Copy for ScalarFields<'a>

impl<'a> Eq for ScalarFields<'a>

impl<'a> StructuralPartialEq for ScalarFields<'a>