This package provides the foundational browser client for resolving identity, checking entitlements, and launching checkout flows—all in under 3KB (minified + gzipped).

Key Features

• Zero Dependencies: Pure Vanilla TypeScript.
• Event-Based Architecture: Built-in Pub/Sub for reactive updates.
• Identity Handling: Automatic Guest fingerprinting and native Auth JWT resolution.
• Tiny footprint: Available as an ESM/CJS module or a <script> tag CDN build.

Installation

npm install @revstackhq/browser

Or via CDN:

<script src="https://unpkg.com/@revstackhq/browser/dist/index.global.js"></script>

Quick Start

Instantiate the RevstackClient once during application startup.

import { RevstackClient } from "@revstackhq/browser";

const client = new RevstackClient({
  publicKey: "rs_pub_12345",
  async getToken() {
    return localStorage.getItem("auth_token");
  },
});

// 1. Initialize to fetch the user's current entitlements
await client.init();

// 2. Check access synchronously from the local cache
if (client.hasAccess("pro_features")) {
  console.log("Welcome to Pro!");
}

// 3. React to changes (e.g., after an upgrade)
const unsubscribe = client.subscribe(() => {
  console.log("Entitlements updated:", client.getEntitlement("pro_features"));
});

API Reference

Launching Checkout

Trigger a Stripe Checkout session securely without backend redirect boilerplate:

await client.startCheckout({
  planId: "price_abc123",
  successUrl: "https://yourapp.com/success",
  cancelUrl: "https://yourapp.com/pricing",
});

Customer Billing Portal

Allow users to manage subscriptions, update cards, or view invoices:

await client.openBillingPortal({
  returnUrl: "https://yourapp.com/settings",
});