History (20%)

Vault history scoring for recent instability, unresolved incidents, and confirmed lifetime loss events.

History measures whether the vault has recently behaved like a stable production system.

This vector is weighted at 20%, equal to Control and Governance. Chronic instability can dampen otherwise-good vaults even when current asset, platform, and timelock inputs look strong.

What It Measures

The history vector consumes vault-scoped event aggregates from the event log — restricted to the incident-class allowlist: realized adverse events (incidents, bad debt and its socialization, emergency pauses and shutdowns, detected proxy mutations). Governance, timelock, and cap-management events keep their severities for display and alerting but are priced by the Control and concentration vectors, not History (PHI-240, methodology v4).

Signal	Treatment
Active Critical events	Time-decayed penalty
Active Warning events	Time-decayed penalty with diminishing returns
Confirmed lifetime Critical loss	Non-decaying penalty for loss-evidenced Critical events
Clean recent history	Small bonus when there are no recent or lifetime Criticals

RatingChange events are excluded so the score does not consume its own output; an all-false PauseAction (an unpause) is likewise excluded — recovery is not an adverse event.

Time Decay

Recent Critical and Warning events matter most.

Age bucket	Weight
≤ 30 days	1.0
≤ 90 days	0.6
≤ 180 days	0.4
≤ 365 days	0.2

Events outside the scoring window do not contribute to the time-decayed component.

Warning Diminishing Returns

Warnings are compressed with a logarithmic count. The first few Warnings are a meaningful instability signal, while clustered rows from one episode (for example a pause flapping during an incident) should not count linearly forever.

This preserves rank order while preventing one noisy episode from forcing every affected vault into the same outcome. Routine curator operations are outside the allowlist entirely and never reach this vector.

Lifetime Critical Loss Penalty

Confirmed Critical loss events do not fully decay. A vault with a proven loss event in its history carries a permanent penalty, capped so repeated historical losses do not drive the vector below zero by themselves.

The lifetime count is evidence-gated. Operational Criticals inside the allowlist, such as emergency pauses or detected proxy mutations, remain time-decayed signals, but they are not treated as permanent loss events unless the record includes loss evidence. Ownership and governance changes sit outside the allowlist entirely and are priced by the Control vector.

Tier Ceiling

History also applies a post-composite ceiling.

History score	Ceiling
< 4.0	4.9
< 7.0	7.5
≥ 7.0	none

The ceiling exists to prevent a vault with chaotic recent history from publishing above the tier its operating record supports.