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Polar

Polar is a developer first payment infrastructure. Out of the box it provides a lot of developer first integrations for payments, checkouts and more. This plugin helps you integrate Polar with Better Auth to make your auth + payments flow seamless.

This plugin is maintained by Polar team. For bugs, issues or feature requests, please visit the Polar GitHub repo.

Installation

Install the plugin

First, install the plugin:

npm install @polar-sh/better-auth

If you're using a separate client and server setup, make sure to install the plugin in both parts of your project.

Install the Polar SDK

Next, install the Polar SDK on your server:

npm install @polar-sh/sdk

Add the plugin to your auth config

auth.ts
import { betterAuth } from "better-auth";
import { polar } from "@polar-sh/better-auth";
import { Polar } from "@polar-sh/sdk";
 
const client = new Polar({
    accessToken: process.env.POLAR_ACCESS_TOKEN,
    // Use 'sandbox' if you're using the Polar Sandbox environment
    // Remember that access tokens, products, etc. are completely separated between environments.
    // Access tokens obtained in Production are for instance not usable in the Sandbox environment.
    server: 'production'
});
 
const auth = betterAuth({
    // ... Better Auth config
    plugins: [
        polar({
            client,
            // Enable automatic Polar Customer creation on signup
            createCustomerOnSignUp: true,
            // Enable customer portal
            enableCustomerPortal: true, // Deployed under /portal for authenticated users
            // Configure checkout
            checkout: {
                enabled: true,
                products: [
                    {
                        productId: "123-456-789", // ID of Product from Polar Dashboard
                        slug: "pro" // Custom slug for easy reference in Checkout URL, e.g. /checkout/pro
                    }
                ],
                successUrl: "/success?checkout_id={CHECKOUT_ID}"
            },
            // Incoming Webhooks handler will be installed at /polar/webhooks
            webhooks: {
                secret: process.env.POLAR_WEBHOOK_SECRET,
                onPayload: ...,
            }
        })
    ]
});

For configuration options and more information, check out Polar's Better Auth docs.

JWT

Authenticate users with JWT tokens in services that can't use the session

Stripe

Stripe plugin for Better Auth to manage subscriptions and payments.

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