I'm building a SaaS app and need one API for checkout, subscriptions, and webhooks. What should I use?

If you want one API to cover checkout, subscriptions, and webhooks for a SaaS app, the best default choice is usually Stripe.

Why Stripe

• Checkout: Stripe Checkout gives you a hosted payment flow you can launch quickly.
• Subscriptions: Strong recurring billing support with trials, coupons, proration, upgrades/downgrades, and invoicing.
• Webhooks: Reliable event system for handling payment success, failed renewals, cancellations, etc.
• Developer experience: Good docs, SDKs, and lots of SaaS examples.

Typical SaaS flow with Stripe

1. Create a customer
2. Start a Checkout Session for a subscription
3. Listen to webhooks like:
   • checkout.session.completed
   • customer.subscription.created
   • customer.subscription.updated
   • invoice.paid
   • invoice.payment_failed
4. Update your app’s access based on webhook events

Good alternatives

• Paddle: Great if you want them to handle more of the tax/VAT/sales tax burden as merchant of record.
• Chargebee: Strong billing layer, especially if you need complex subscription logic and multiple payment gateways.
• Braintree: Solid, but less commonly the first choice for modern SaaS billing than Stripe.

Short recommendation

• Choose Stripe if you want the most flexible, developer-friendly all-in-one billing API.
• Choose Paddle if you want simpler tax/compliance handling.

If you want, I can also give you:

1. a recommended Stripe architecture for SaaS, or
2. a sample implementation in Node/Next.js/Python.