S
saas-scaffold
Payments

Add subscriptions and checkout flows with webhook-driven access control.

Last updated December 18, 2025

At a glance

What you get
  • Checkout flow
  • Webhook handling
  • Subscription state tracking
You'll configure
  • Payment provider keys
  • Webhook secret
  • Product IDs / price IDs

Quickstart

1
Add payment provider keys

Add your provider API keys and webhook secret to .env.local (POLAR_ACCESS_TOKEN, POLAR_WEBHOOK_SECRET, etc.).

2
Create subscription products

Create your subscription tiers/prices in your provider dashboard (Polar.sh, Stripe, etc.).

3
Configure webhook endpoint

Point webhooks to your app's /api/webhooks/[provider] route and verify signature validation is enabled.

4
Test checkout flow

Visit /pricing, select a plan, complete checkout, and verify subscription state updates in the dashboard.

Providers

Pick an option below. Each provider has a short guide so you can implement without digging through docs.

Polar
Available
Expand

Default in the current scaffold. Subscriptions + customer portal with Polar.

Read guide
Stripe
Coming soon
Expand

Industry standard payments. Subscriptions, invoices, coupons, and more.

Read guide
Lemon Squeezy
Coming soon
Expand

Fast SaaS billing and digital products with a simple setup.

Read guide

Code

Copy/paste-friendly code blocks. Designed to get you working quickly without digging through long docs.

.env.local (Polar)

Keys needed to enable checkout + webhook handling.

# Polar
POLAR_ACCESS_TOKEN="your-polar-access-token"
POLAR_WEBHOOK_SECRET="your-webhook-secret"
POLAR_SUCCESS_URL="http://localhost:3000/success"
NEXT_PUBLIC_STARTER_TIER="your-starter-tier-id"
NEXT_PUBLIC_STARTER_SLUG="your-org-slug"
Run a local webhook test

Once deployed, you’ll point your provider’s webhook to your /api route.

$ # provider dashboard → set webhook URL
$ # verify signature validation is enabled