@edgerules/web

EdgeRules decision service for the browser. Ships two builds:

The browser package is API-identical to @edgerules/node; only the underlying WASM loader differs (browser fetch vs Node.js fs). Choose this package for Vite, webpack, and other browser bundler setups.

Installation

npm install @edgerules/web @edgerules/portable

ESM only. The WASM binary is loaded asynchronously on first use.

Production Usage

Load from an EdgeRules DSL string

import {DecisionService} from '@edgerules/web';

const service = new DecisionService(`{
    applicant: {
        age:    <number, required: true>
        income: <number, default: 0>
    }
    isEligible: applicant.age >= 18 and applicant.income >= 1000
}`);

// Execute the whole model against a request
const result = service.execute('*', {applicant: {age: 25, income: 2500}});
// { applicant: { age: 25, income: 2500 }, isEligible: true }

Load from a Portable JSON model

import {DecisionService} from '@edgerules/web';
import type {PortableContext} from '@edgerules/portable';

const model: PortableContext = {
    '@kind': 'context',
    fields: {
        minAge: 18,
        minIncome: 1000,
        applicant: {
            '@kind': 'context',
            fields: {age: {'@kind': 'placeholder', type: 'number'}, income: {'@kind': 'placeholder', type: 'number'}},
        },
        isEligible: 'applicant.age >= minAge and applicant.income >= minIncome',
    },
};

const service = new DecisionService(model);

const result = service.execute('isEligible', {applicant: {age: 30, income: 3000}});
// true

Error handling

import type {PortableError} from '@edgerules/portable';

try {
    service.execute('nonExistentField');
} catch (err) {
    const error = err as PortableError;
    console.error(error.type);    // "EntryNotFound"
    console.error(error.message); // human-readable, safe to surface in UI
}

Mutable / Development Usage

Use the ./mutable subpath for rule editors, visual builders, and test tooling. Do not use this build in production.

import {Kinds, MutableDecisionService} from '@edgerules/web/mutable';

const service = new MutableDecisionService(initialModel);

// Inspect a field with inferred type information
const node = service.get('applicant.age');
// { "@kind": "placeholder", "type": "number", "required": true, "writeOnly": true, "linked": true }

// Hot-update a rule
service.set('minAge', 21);

// Add a new typed input
service.set('applicant.creditScore', {'@kind': 'placeholder', type: 'number', default: 0});

// Remove a field
service.remove('applicant.creditScore');

// Read the full model snapshot
const snapshot = service.get('*');

// Read the method signatures only
const signatures = service.get('*', Kinds.METHOD_INTERFACES);

// Read/write a node as DSL source text instead of Portable JSON
const code = service.getCode('minAge'); // '21'
service.setCode('minAge', '18'); // returns a PortableNode, not code text

API Reference

DecisionService

execute details

• method: "*" — evaluates every top-level field and returns the full model result.
• method: "person.isAdult" — evaluates and returns that single field.
• method: "validateApplicant" — calls a named function; supply its parameters through args.
• args — a model-shaped object whose entries are bound as external inputs. Nested typed holes follow the model shape (e.g. { applicant: { age: 30 } } for applicant: { age: <number> }).

MutableDecisionService (dev build)

Inherits execute and adds:

Related packages

• @edgerules/node — same API for Node.js
• @edgerules/portable — Portable JSON type definitions