Struct Trace 

pub struct Trace {

    pub trace_id: Uuid,
    pub prev_hash: String,
    pub tenant_id: String,
    pub session_id: String,
    pub ts: Timestamp,
    pub mode: Mode,
    pub policy: PolicyRef,
    pub request: RequestInfo,
    pub attempts: Vec<Attempt>,
    pub deferred: Vec<DeferredVerdict>,
    pub final_: FinalOutcome,
    pub probe: Option<ProbeSignal>,
    pub rollout: Option<RolloutRecord>,
    pub shadow: Option<ShadowSignal>,
    pub route_ix: Option<u32>,
    pub predicted_pass: Option<f64>,
    pub elastic: Option<ElasticDecision>,
}

A single routing decision, start to finish.

Fields

trace_id: Uuid

Time-ordered unique id (UUIDv7).

prev_hash: String

Hash of the previous record in this chain (or crate::hashchain::GENESIS_HASH).

tenant_id: String

Tenant this trace belongs to.

session_id: String

Session (e.g. an agent run) this request is part of.

ts: Timestamp

When the decision was made.

mode: Mode

Serving mode in effect.

policy: PolicyRef

Which policy produced this decision.

request: RequestInfo

The request that was routed.

attempts: Vec<Attempt>

Every attempt made, cheapest rung first.

deferred: Vec<DeferredVerdict>

Verdicts that arrived after serving (deferred gates, feedback API). Attach over time.

final_: FinalOutcome

The final served outcome and its economics.

probe: Option<ProbeSignal>

Shadow probe signal (ADR 0008 Phase 1). Absent when probe is off (the default) or when this request was not in the configured sample_rate — byte-identical to pre-probe traces and hash-chain compatible (the skip_serializing_if keeps absent = absent).

rollout: Option<RolloutRecord>

Which rollout arm this request was in (ADR 0009 D1). Absent when the route has no rollout configured.

shadow: Option<ShadowSignal>

Counterfactual signal from shadow scoring (ADR 0009 D2). Absent unless shadow is enabled.

route_ix: Option<u32>

Index of the route that handled this request, so a downstream outcome arriving later can be attributed to the route that actually produced it (ADR 0009 D3).

Without this the guardrail has to pool every tenant’s outcomes onto one route, which in a multi-route config means a failing route can be masked by healthy siblings — the guard would sit green while the thing it guards degrades. Absent on traces written before this field existed; the guardrail treats absent as route 0, its prior behaviour.

predicted_pass: Option<f64>

Shadow prediction of P(gate-pass) for the start rung (ADR 0008 Phase 2), from the per-query predictor. Absent when the predictor is off (the default) — byte-identical to pre-predictor traces and hash-chain compatible. Recorded but never acted on in this phase.

elastic: Option<ElasticDecision>

Elastic verification decision (ADR 0008 Phase 3) on the served rung: why the expensive gates were skipped or run, plus the λ / calibration provenance the skip was authorized under. Absent when elastic is off (the default) — byte-identical to pre-elastic traces and hash-chain compatible (the skip_serializing_if keeps absent = absent).

Implementations

impl Trace

pub fn hash(&self) -> Result<String>

This record’s own hash (SHA-256 over its canonical JSON) — the value the next record stores as its prev_hash.

Errors

Returns crate::Error::Json if the trace cannot be serialized.

pub fn recompute_savings(&mut self) -> f64

Compute savings_usd = baseline - total and store it, keeping the field consistent with the two it is derived from. Returns the savings.

Trait Implementations

impl Chained for Trace

fn prev_hash(&self) -> &str

The hash of the preceding record (or GENESIS_HASH for the first).

impl Clone for Trace

fn clone(&self) -> Trace

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Trace

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Trace

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Trace

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

Formats the value using the given formatter.

impl PartialEq for Trace

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Trace

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 Trace