Struct SkillStats 

pub struct SkillStats {

    pub schema_version: u32,
    pub skill_name: String,
    pub skill_version: String,
    pub manifest_digest: String,
    pub lifecycle_state: LifecycleState,
    pub lifecycle_changed_at: DateTime<Utc>,
    pub pinned: bool,
    pub pinned_reason: String,
    pub usage_count: u64,
    pub success_count: u64,
    pub failure_count: u64,
    pub last_used_at: Option<DateTime<Utc>>,
    pub last_success_at: Option<DateTime<Utc>>,
    pub first_successful_use_at: Option<DateTime<Utc>>,
    pub anchor_confidence: f64,
    pub rebuilt_from_trace_through: Option<DateTime<Utc>>,
    pub resolution_misses: u64,
}

Sidecar stats for an installed skill. Not part of the signed manifest.

Schema evolution policy: additive only. New fields MUST be marked #[serde(default)] so older mur builds reading newer files (and newer builds reading older files) parse cleanly without migration. Do not pre-reserve fields without a producer — empty defaults create semantic ambiguity (“never set” vs “set to empty”). Add fields when their callers exist.

Fields

schema_version: u32

skill_name: String

skill_version: String

manifest_digest: String

SHA-256 of the manifest content at the time these stats were (re)initialised. A mismatch on load tells us the skill was reinstalled — see reset_on_manifest_change().

lifecycle_state: LifecycleState

lifecycle_changed_at: DateTime<Utc>

pinned: bool

pinned_reason: String

usage_count: u64

success_count: u64

failure_count: u64

last_used_at: Option<DateTime<Utc>>

last_success_at: Option<DateTime<Utc>>

first_successful_use_at: Option<DateTime<Utc>>

anchor_confidence: f64

Confidence at the moment of the most recent successful use (or most recent promotion — see lifecycle::on_promotion). Decay is computed from this anchor, never incrementally — keeps the value numerically stable and idempotent on read.

rebuilt_from_trace_through: Option<DateTime<Utc>>

Watermark for incremental reindex — the trace timestamp that these stats have already absorbed. mur skill reindex-stats resumes from here.

resolution_misses: u64

Count of inject-time Resolution::Unresolved outcomes for this skill. A spike here means the skill declares intents that no longer match the agent’s MCP inventory — doctor’s intent-resolvable check surfaces this.

Implementations

impl SkillStats

pub fn new( skill_name: &str, skill_version: &str, manifest_digest: &str, now: DateTime<Utc>, ) -> Self

pub fn path(mur_home: &Path, skill_name: &str) -> PathBuf

pub fn path_agent(mur_home: &Path, agent: &str, skill_name: &str) -> PathBuf

Per-agent stats path: <MUR_HOME>/agents//skills//stats.json

pub fn load(path: &Path) -> Result<Option<Self>>

Read the sidecar, or return None if absent. Lock-free — fine for read-mostly callers (doctor, info, stats). Concurrent writers going through merge_in_place will not corrupt the file because they hold the exclusive lock during the write window.

pub fn merge_in_place( path: &Path, default: impl FnOnce() -> Self, merge_fn: impl FnOnce(&mut Self) -> Result<()>, ) -> Result<()>

Read-merge-write under an exclusive fd-lock. merge_fn is called with the loaded value (or the supplied default if none exists) and is responsible for applying the delta. The lock window is microseconds — counter increments only.

pub fn is_stale(&self, current_digest: &str) -> bool

Returns true if the loaded stats refer to a different manifest digest than the one currently installed. Callers (the aggregator and reindex) should reset() in that case rather than carry counters across an upgrade.

A version bump resets usage_count / success_count / failure_count but preserves pinned, first_successful_use_at, and lifecycle_state (a Canonical skill bumping to 1.2.0 should not regress to Draft).

pub fn reset_for_new_manifest( &mut self, new_version: &str, new_digest: &str, now: DateTime<Utc>, )

Reset counters for a manifest change, preserving pinned state and first-success timestamp.

Trait Implementations

impl Clone for SkillStats

fn clone(&self) -> SkillStats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SkillStats

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for SkillStats

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for SkillStats

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

where __S: Serializer,

Serialize this value into the given Serde serializer.