Decision Engine Overview

Introduction to the Decision Engine

The Decision Engine is Banking.Live’s real-time transaction decisioning layer. It allows clients to define how transactions should be evaluated, controlled, and acted on across the platform using configurable rules, instead of relying on fixed engineering-led logic.

It replaces the legacy Rules Engine with a more scalable and reusable model for transaction decisioning. Rather than recreating the same logic across multiple card programs, products, or rule groups, clients can define rules once, apply them at the appropriate scope, and tailor outcomes where needed. This reduces duplication, improves consistency, and makes decisioning behaviour easier to maintain over time.

At runtime, the Decision Engine evaluates live transaction data in real time and determines what should happen next. Depending on the configured rules and actions, it can decline a transaction, apply a fee, trigger an alert, block a card or merchant, or enforce customer-specific controls.

It also acts as a real-time signalling layer. Clients can use rules to identify transactions of interest and attach action attributes that are returned through FAST, allowing their own systems to trigger downstream processes such as promotions, rewards, fulfilment, or partner-specific services. This makes it more than a fraud tool. It acts as a flexible policy, orchestration, and signalling layer for transaction behaviour across Banking.Live, enabling clients to control transaction outcomes in real time and trigger downstream processes in their own systems.

The Decision Engine also enables more context-aware decisioning than the legacy model. Rules can evaluate transaction attributes, historical behaviour, re-usable lists, and configurable parameters, including card-level overrides managed through APIs. This allows clients to implement sophisticated controls and experiences without repeatedly rebuilding similar rules.

By separating rule conditions from rule actions, the Decision Engine supports a more modular design. Clients can reuse decision logic, adapt policy more quickly, and introduce differentiated behaviour across clients, products, account & card groups, and individual cards with less operational overhead.

This documentation explains how the Decision Engine works, how rules and actions are configured, and how to manage and monitor decisioning behaviour through APIs and the user interface.

Why It Matters

The Decision Engine helps clients:

• Define transaction decisioning behaviour without repeated engineering changes
• Reuse rules across multiple products, groups, and card programs
• Reduce duplication and simplify ongoing rule maintenance
• Apply more precise controls using real-time transaction data and historical context
• Support customer-specific or card-level behaviour through configurable parameters
• Power more than fraud controls, including fees, spend controls, merchant restrictions, and real-time automation

Core Concepts

Typical Use Cases

The Decision Engine can be used to support scenarios such as:

• Declining transactions based on merchant, MCC, transaction type, geography, or channel
• Enforcing spend controls and usage restrictions
• Applying differentiated fee behaviour across products or account groups
• Supporting cardholder-adjustable transaction settings
• Creating customer-specific controls without duplicating rules
• Triggering real-time alerts or automated actions when transaction conditions are met
• Flagging transactions for downstream client workflows, such as promotions, merchant partnerships, rewards handling, or other real-time services triggered from FAST data