Show HN: Guantr - A Type-Safe JS/TS Authorization Library

4 hours ago 2

Flexible, type-safe JavaScript library for efficient authorization and permission checking. Easily manage permissions, and context-aware access control with minimal overhead and a simple API.

Install package:

# ✨ Auto-detect npx nypm install guantr # npm npm install guantr # yarn yarn add guantr # pnpm pnpm install guantr # bun bun install guantr # deno deno install guantr

Import:

ESM (Node.js, Bun, Deno)

import { createGuantr } from "guantr";

CommonJS (Legacy Node.js)

const { createGuantr } = require("guantr");

CDN (Deno, Bun and Browsers)

import { createGuantr } from "https://esm.sh/guantr";

Initialize:

const guantr = await createGuantr() // With Typescript Meta: type Meta = GuantrMeta<{ post: { action: 'create' | 'read' | 'update' | 'delete' model: { id: number, title: string, published: boolean } } }>; const guantr = await createGuantr<Meta>() // Contextual const user = { id: number, name: 'John Doe', roles: ['admin'] } const guantrWithContext = await createGuantr<Meta, { user: typeof user }>({ getContext: () => ({ user }) })

Setting rules:

await guantr.setRules((can, cannot) => { can('read', 'post') cannot('read', ['post', { published: ['eq', false] }]) }) // Or await guantr.setRules([ { resource: 'post', action: 'read', condition: null, effect: 'allow' }, { resource: 'post', action: 'read', condition: { published: ['eq', false] }, effect: 'deny' } ])

Rules also can be set on instance creation:

const guantr = await createGuantr<Meta>([ { resource: 'post', action: 'read', condition: { published: ['eq', false] }, effect: 'deny' } ])

Authorize:

await guantr.can('read', 'post') // true const post = { id: 1, title: 'Hello World', published: false } await guantr.can('read', ['post', post]) // false

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