Struct Trace 

pub struct Trace {

    pub case_id: String,
    pub agent_sha: String,
    pub model: String,
    pub context_version: Option<String>,
    pub context_sha: String,
    pub question: String,
    pub sql_executed: Option<String>,
    pub result: Value,
    pub cost: Option<f64>,
    pub latency_ms: u64,
    pub turns: Option<u64>,
    pub tool_calls: Option<u64>,
    pub backend: Backend,
}

One captured case result. The result is stored as the raw {columns, rows} JSON value (the same object capture embeds) so no Serialize is needed on the compare crate’s Table; it is deserialized back into a Table at re-score time.

sql_executed and tool_calls are schema slots the P4 trace shape reserves, but the single-shot claude -p --output-format json envelope does not expose either (only num_turns), so they are captured as None today. turns (from num_turns) is the delivered per-case diagnostic; full SQL / tool-call granularity would need --output-format stream-json (a later change).

Fields

case_id: String

agent_sha: String

model: String

context_version: Option<String>

The golden’s symbolic context_version pin (informational), e.g. driftwood@a1b2c3d.

context_sha: String

The computed MDL SHA of the bound project — the context_sha key component.

question: String

The question the result answers. Part of the key: if a case’s question changes under the same id, the cached result is for a different prompt and must be re-run (a miss).

sql_executed: Option<String>

The SQL the agent executed. Not exposed by the --output-format json result envelope; None.

result: Value

The captured {columns, rows} result object.

cost: Option<f64>

None when the backend that produced this trace couldn’t report cost — absent is not zero.

latency_ms: u64

turns: Option<u64>

Conversation turns (num_turns) — the round-trip count (“4–8 round-trips” per case, typically). None when the backend couldn’t report a turn count.

tool_calls: Option<u64>

Tool-call count. Not exposed by the JSON result envelope; None (see struct docs).

backend: Backend

Which back-end/runtime produced this trace — part of the cache key (see CaseKey::backend) so a trace from one back-end is never replayed as another’s result. #[serde(default)] so a pre-existing on-disk trace (no field at all) deserializes to Backend::default — the back-end that behavior always meant before this dimension existed.

Trait Implementations

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 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.