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[AVAILABLE]. packages/policy, 61 tests. CLAIMS.md 2.2/2.3.

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Purpose

Evaluates a PolicySignals object against a Policy’s ordered rules and returns exactly one Decision. See Policies and the decision for the concept, this page is the export reference.

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Install

npm install @parmana/policy

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Key exports

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Engine, [AVAILABLE]

ExportSignature
PolicyEngine.evaluate(policy: Policy, input: PolicyInput): PolicyDecision, first-match-wins over policy.rules, unmatched input rejects

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Routing and loading, [AVAILABLE]

ExportPurpose
PolicyRouterResolves a PolicyReference { name, version, schemaVersion } to a loaded Policy
PolicyRegistryIn-memory policy lookup by name/version
PolicyRepository (type)The interface FilePolicyRepository and any custom repository implement
FilePolicyRepositorynew FilePolicyRepository(directory: string), resolves <directory>/<name>/<version>/policy.json

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Validation, [AVAILABLE]

ExportPurpose
PolicyValidatorChecks a loaded policy’s identity (policyId/policyVersion) matches what was requested before evaluation runs
SignalValidatorValidates submitted signals against a policy’s signalsSchema

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Types

Policy, PolicyRule, PolicyCondition, PolicyRuleOutcome, PolicyInput, PolicySignals, PolicyDecision, PolicyAction (enum: APPROVE, REJECT, REQUIRE_OVERRIDE), PolicyOutcome (enum: APPROVE, REJECT, REQUIRE_OVERRIDE).

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Minimal example

import { FilePolicyRepository, PolicyEngine } from "@parmana/policy";

const repository = new FilePolicyRepository("policies");
const policy = await repository.load("vendor-payment", "2.0.0");

const engine = new PolicyEngine();
const decision = engine.evaluate(policy, {
  vendorVerified: true, invoiceVerified: true, paymentApproved: true,
  sufficientFunds: true, paymentAmount: 1000, riskScore: 5,
});
// decision.outcome === "APPROVE"
Full runnable version: Write your first policy.

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Next

Write your first policy

Write a policy and confirm both the approve and reject paths.

@parmana/runtime

Where PolicyEngine is actually invoked as part of executing a transaction.