Thresholds and decisions

fraud_score

Estimated fraud probability in [0.0, 1.0]. Higher values indicate greater risk. The score is calibrated with chargebacks and confirmed labels.

Band	Score range	risk_level	Typical decision
Low	≤ 0.25	`LOW`	`APPROVE`
Medium	≤ 0.55	`MEDIUM`	`REVIEW`
High	≤ 0.80	`HIGH`	`REVIEW`
Critical	> 0.80	`CRITICAL`	`REJECT`

Your client may have custom thresholds. When they apply, the response includes threshold_used:

{
  "threshold_used": {
    "low_max": 0.25,
    "medium_max": 0.55,
    "high_max": 0.80
  }
}

Field	Description
`low_max`	Maximum inclusive score for LOW band
`medium_max`	Maximum inclusive score for MEDIUM band
`high_max`	Maximum inclusive score for HIGH band. Above → CRITICAL

threshold_used may be null when the decision comes only from deterministic rules.

The rules engine (global + per client) can override the ML model decision. In that case decision_source is RULES.

true when the transaction meets SARLAFT/UIAF criteria (typically REJECT or CRITICAL). Your compliance team should review these cases.