Better Auth

Overview

Welcome to the integration guide for Creem and Better Auth! This integration enables you to combine powerful authentication capabilities with seamless payment processing and subscription management. Better Auth is a modern authentication framework for TypeScript that provides comprehensive user management, session handling, and authentication flows. By integrating Better Auth with Creem, you can:

Automatically synchronize customer and subscription data with your users
Grant or revoke access based on subscription status
Manage subscriptions directly through your authentication layer
Handle payments and billing for authenticated users
Prevent trial abuse across multiple subscriptions

What you'll learn

How to integrate Better Auth with Creem to build a complete authentication and payment solution for your SaaS application.

Requirements

A Creem account
Your Creem API keys
A TypeScript/JavaScript application
A database (PostgreSQL, MySQL, or SQLite)

Installation

Install the plugin

Install the Better Auth Creem plugin in your project:

npm install @creem_io/better-auth

pnpm add @creem_io/better-auth

yarn add @creem_io/better-auth

bun install @creem_io/better-auth

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

Get your Creem API Key

Navigate to the Creem dashboard
Click on the “Developers” menu
Copy your API key
Add it to your environment variables:

# .env
CREEM_API_KEY=your_api_key_here

Test Mode and Production have different API keys. Make sure you’re using the correct one for your environment.

Configuration

Server Configuration

Configure Better Auth with the Creem plugin:

// lib/auth.ts
import { betterAuth } from 'better-auth';
import { creem } from '@creem_io/better-auth';

export const auth = betterAuth({
  database: {
    // your database config
  },
  plugins: [
    creem({
      apiKey: process.env.CREEM_API_KEY!,
      webhookSecret: process.env.CREEM_WEBHOOK_SECRET, // Optional
      testMode: true, // Use test mode for development
      defaultSuccessUrl: '/success', // Redirect URL after payments
      persistSubscriptions: true, // Enable database persistence (recommended)
    }),
  ],
});

Client Configuration

// lib/auth-client.ts
import { createAuthClient } from 'better-auth/react';
import { creemClient } from '@creem_io/better-auth/client';

export const authClient = createAuthClient({
  baseURL: process.env.NEXT_PUBLIC_APP_URL,
  plugins: [creemClient()],
});

Database Migration

Generate and run the database schema for subscription persistence:

npx @better-auth/cli generate
npx @better-auth/cli migrate

Webhook Setup

Create Webhook in Creem Dashboard

Go to your Creem dashboard
Click on the “Developers” tab
Navigate to the “Webhooks” section
Click “Add Webhook”
Enter your webhook URL:

https://your-domain.com/api/auth/creem/webhook

The /api/auth prefix is the default Better Auth server path. Adjust if you’ve customized your Better Auth configuration.

Configure Webhook Secret

Copy the webhook signing secret from Creem
Add it to your environment variables:

CREEM_WEBHOOK_SECRET=your_webhook_secret_here

Update your server configuration to include the webhook secret (shown in Configuration section above)

Local Development (Optional)

For local testing, use ngrok to expose your local server:

ngrok http 3000

Then add the ngrok URL to your Creem webhook settings.

Usage Examples

Create Checkout Session

Allow users to subscribe to your products:

"use client";

import { authClient } from "@/lib/auth-client";

export function SubscribeButton({ productId }: { productId: string }) {
  const handleCheckout = async () => {
    const { data, error } = await authClient.creem.createCheckout({
      productId,
      successUrl: "/dashboard",
      discountCode: "LAUNCH50", // Optional
      metadata: { planType: "pro" }, // Optional
    });

    if (data?.url) {
      window.location.href = data.url;
    }
  };

  return <button onClick={handleCheckout}>Subscribe Now</button>;
}

Customer Portal

Let users manage their subscriptions:

const handlePortal = async () => {
  const { data } = await authClient.creem.createPortal();

  if (data?.url) {
    window.location.href = data.url;
  }
};

Check Subscription Access

Verify if a user has an active subscription:

const { data } = await authClient.creem.hasAccessGranted();

if (data?.hasAccess) {
  // User has active subscription
  console.log(`Access expires: ${data.expiresAt}`);
}

Cancel Subscription

Allow users to cancel their subscription:

const handleCancel = async () => {
  const { data, error } = await authClient.creem.cancelSubscription();

  if (data?.success) {
    console.log('Subscription canceled successfully');
  }
};

Access Control with Webhooks

The plugin provides high-level handlers to manage user access automatically:

// lib/auth.ts
import { betterAuth } from 'better-auth';
import { creem } from '@creem_io/better-auth';

export const auth = betterAuth({
  database: {
    // your database config
  },
  plugins: [
    creem({
      apiKey: process.env.CREEM_API_KEY!,
      webhookSecret: process.env.CREEM_WEBHOOK_SECRET!,

      onGrantAccess: async ({ reason, product, customer, metadata }) => {
        const userId = metadata?.referenceId as string;

        // Grant access in your database
        await db.user.update({
          where: { id: userId },
          data: {
            hasAccess: true,
            subscriptionTier: product.name,
          },
        });

        console.log(`Granted access to ${customer.email}`);
      },

      onRevokeAccess: async ({ reason, product, customer, metadata }) => {
        const userId = metadata?.referenceId as string;

        // Revoke access in your database
        await db.user.update({
          where: { id: userId },
          data: {
            hasAccess: false,
          },
        });

        console.log(`Revoked access from ${customer.email}`);
      },
    }),
  ],
});

Server-Side Usage

Use Creem functions directly in Server Components or API routes:

import { checkSubscriptionAccess } from "@creem_io/better-auth/server";
import { auth } from "@/lib/auth";
import { headers } from "next/headers";
import { redirect } from "next/navigation";

export default async function DashboardPage() {
  const session = await auth.api.getSession({ headers: await headers() });

  if (!session?.user) {
    redirect("/login");
  }

  const status = await checkSubscriptionAccess(
    {
      apiKey: process.env.CREEM_API_KEY!,
      testMode: true,
    },
    {
      database: auth.options.database,
      userId: session.user.id,
    }
  );

  if (!status.hasAccess) {
    redirect("/subscribe");
  }

  return (
    <div>
      <h1>Welcome to Dashboard</h1>
      <p>Subscription Status: {status.status}</p>
    </div>
  );
}

Key Features

Automatic Trial Abuse Prevention

When using database mode, the plugin automatically prevents users from abusing trial periods. Each user can only receive one trial across all subscription plans.

Database Persistence

Store subscription data in your database for fast access checks without API calls. This enables:

Offline access to subscription data
SQL queries for subscription management
Automatic synchronization via webhooks

Transaction History

Search and filter transaction records for authenticated users:

const { data } = await authClient.creem.searchTransactions({
  productId: 'prod_xyz789', // Optional filter
  pageNumber: 1,
  pageSize: 50,
});

Best Practices

Always test in development - Use test mode and a development environment before going live
Implement error handling - Handle payment failures and webhook errors gracefully
Monitor webhooks - Set up logging and alerts for webhook processing
Use database mode - Enable persistSubscriptions for better performance and features
Protect sensitive routes - Use middleware or server-side checks to protect premium content
Validate subscriptions - Always verify subscription status before granting access to premium features

Additional Resources

Support

Need help with the integration?

Join our Discord community for real-time support
Chat with us directly using the in-app live chat on the Creem dashboard
Contact us via our support form
Open an issue on GitHub

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Overview

Requirements

Installation

Install the plugin

Get your Creem API Key

Configuration

Server Configuration

Client Configuration

Database Migration

Webhook Setup

Create Webhook in Creem Dashboard

Configure Webhook Secret

Local Development (Optional)

Usage Examples

Create Checkout Session

Customer Portal

Check Subscription Access

Cancel Subscription

Access Control with Webhooks

Server-Side Usage

Key Features

Automatic Trial Abuse Prevention

Database Persistence

Transaction History

Best Practices

Additional Resources

Support

​Overview

Requirements

​Installation

​Install the plugin

​Get your Creem API Key

​Configuration

​Server Configuration

​Client Configuration

​Database Migration

​Webhook Setup

​Create Webhook in Creem Dashboard

​Configure Webhook Secret

​Local Development (Optional)

​Usage Examples

​Create Checkout Session

​Customer Portal

​Check Subscription Access

​Cancel Subscription

​Access Control with Webhooks

​Server-Side Usage

​Key Features

​Automatic Trial Abuse Prevention

​Database Persistence

​Transaction History

​Best Practices

​Additional Resources

​Support

Overview

Installation

Install the plugin

Get your Creem API Key

Configuration

Server Configuration

Client Configuration

Database Migration

Webhook Setup

Create Webhook in Creem Dashboard

Configure Webhook Secret

Local Development (Optional)

Usage Examples

Create Checkout Session

Customer Portal

Check Subscription Access

Cancel Subscription

Access Control with Webhooks

Server-Side Usage

Key Features

Automatic Trial Abuse Prevention

Database Persistence

Transaction History

Best Practices

Additional Resources

Support