Response:
"user_id": "u12345", "session_id": "s789", "event_type": "payment_initiation", "amount": 9500, "recipient": "new_account", "behavioral_data": ... // sent by SDK automatically Response: "user_id": "u12345"
"risk_score": 890, "decision": "challenge", "recommended_action": "step_up_auth", "reason_codes": ["unusual_typing_speed", "new_device"] Response: "user_id": "u12345"