@orkestrel/qualifier

A synchronous, deterministic eligibility engine that runs a pure, JSON-serializable QualificationDefinition's ordered passes against one subject through one @orkestrel/reason engine and returns a fresh QualificationResult carrying global and scoped eligibility, evidence-rich findings, and quantitative derivations.

Author the passes — quantitative derivations and logical rule gates — hand a subject (a plain data record) to qualify, and read what comes back. The caller supplies the definition; Qualifier only evaluates what it is given. Inject a @orkestrel/reason ReasonInterface where qualification shares an engine with the rest of your reasoning, and call destroy() when the qualifier's work is done. Environment-agnostic — no I/O, no browser or server assumptions. Part of the @orkestrel line.

Install

npm install @orkestrel/qualifier

Requirements

• Node.js >= 22.12.0
• ESM (import) and CommonJS (require) through the exports field

Usage

import { createQualificationDefinition, createQualifier, createRuling } from '@orkestrel/qualifier'
import { createAtom, createLogicalDefinition, createRule } from '@orkestrel/reason'

const gates = createLogicalDefinition('gates', 'Eligibility gates', [
	createRule(
		'licensed',
		[createAtom('licensed', 'equals', false)],
		createAtom('blocked', 'equals', true),
	),
])

const definition = createQualificationDefinition('standard', 'Standard eligibility', [gates], {
	rulings: [
		createRuling('license', 'gates', 'licensed', 'restriction', {
			message: 'A license is required',
		}),
	],
})

const qualifier = createQualifier()
const result = qualifier.qualify({ id: 'risk-1', licensed: false }, definition)

result.eligibility // 'ineligible'
result.findings[0]?.message // 'A license is required'
result.derivations // [] — no quantitative pass ran

qualifier.destroy()

qualify accepts exactly one subject per call — there is no batch-of-subjects overload. Every qualify call fires once through qualifier.emitter (qualify).

Guide

For the full surface — Qualifier, QualificationResult, finding types, validators, factories, errors, and options — see guides/qualifier.md.

Package

Published as a single typed entry point per the exports field in package.json.

License

MIT © Orkestrel — see LICENSE.