@guardrail-sim/policy-engine

Rules engine for B2B pricing policies. Define margin floors, discount caps, and volume tiers — evaluate orders against them deterministically.

Built on json-rules-engine. Part of guardrail-sim.

Install

npm install @guardrail-sim/policy-engine

Quick Start

import { PolicyEngine, defaultPolicy } from '@guardrail-sim/policy-engine';

const engine = new PolicyEngine(defaultPolicy);

const result = await engine.evaluate(
  { order_value: 5000, quantity: 100, product_margin: 0.4 },
  0.12 // 12% proposed discount
);

result.approved; // true
result.violations; // [] — no violations
result.calculated_margin; // 0.28

The default policy ships with three rules: 15% margin floor, 25% discount cap, and volume-based tiers (10% base, 15% for 100+ units).

API

• PolicyEngine(policy) — create an engine from a policy definition
• engine.evaluate(order, discount) — check a proposed discount against the rules
• calculateMaxDiscount(order) — find the highest discount an order can receive
• calculateAllocations(amount, lineItems, method) — split a discount across line items
• defaultPolicy — the built-in policy (good for testing and demos)

Docs

• Getting Started
• Policy Concepts

License

MIT