Sensitivity

Title: Sensitivity

How aggressively an anomaly trigger fires, as a level rather than a threshold.

Each level is a point on the detector’s recall-versus-false-positive curve, fixed to a false-positive budget that is the same on every contract:

Level	1	2	3	4	5	6	7	8	9	10
Fires on	0.01%	0.02%	0.05%	0.1%	0.2%	0.5%	1%	2%	5%	10%
Higher is more sensitive: it catches more, and fires on more benign traffic. The
threshold behind a level is resolved per contract, from that contract’s own history,
where the trigger is evaluated. One level therefore means one budget everywhere, and a
retrain moves the threshold without touching this code.
An assertion never names a basis-point score for that reason. A threshold belongs to one
contract and one model version; copy it to a second contract, or keep it across a retrain,
and the trigger mis-configures in the direction that hurts. It stops firing while still
looking healthy.
Firing is not blocking. A trigger that fires runs the assertion, and the assertion decides.
Pair an anomaly trigger with a damage check and only what is both unusual and doing
damage gets blocked. See `src/protection/anomaly`.

Constants

Fires on 0.01% of this contract’s transactions. Catches the least.

uint8 internal constant LEVEL_1 = 1

uint8 internal constant LEVEL_2 = 2

uint8 internal constant LEVEL_3 = 3

uint8 internal constant LEVEL_4 = 4

uint8 internal constant LEVEL_5 = 5

uint8 internal constant LEVEL_6 = 6

Fires on 1% of this contract’s transactions. The recommended operating point.

uint8 internal constant LEVEL_7 = 7

uint8 internal constant LEVEL_8 = 8

uint8 internal constant LEVEL_9 = 9

Fires on 10% of this contract’s transactions. Catches the most.

uint8 internal constant LEVEL_10 = 10

The strictest level, and the loosest, the bounds a valid level lies within.

uint8 internal constant MIN = LEVEL_1

uint8 internal constant MAX = LEVEL_10

Whether level names a rung of the ladder.

0 is not a level: it is the “cleared nothing” sentinel an unscored target reads back in PhEvm.AnomalyContext.firesAt.

function isValid(uint8 level) internal pure returns (bool);