Shadow Mode

What is shadow mode?

Shadow mode runs new or experimental rules in parallel with your active production rules. The live decision returned to your platform is unchanged — shadow rules evaluate silently and their results appear in the API response under shadowEvaluation.

Use cases

• Validate a new velocity rule before promoting it to production
• Compare ML model output against existing rule-based decisions
• Measure false-positive impact on historical traffic patterns
• Run A/B tests on rule configurations without customer impact

Reading shadow results

When shadow rules are active, the scoring response includes:

• →hasShadowRules — whether any shadow rules were evaluated
• →shadowDecision — what the shadow rules would have decided
• →shadowRiskScore — the risk score from shadow evaluation

How to enable

Shadow mode is configured per rule in the MaiGuard dashboard. Mark a rule as shadow-only when creating or editing it. Shadow rules never affect the live decision but are fully evaluated on every matching transaction.