---
title: 'Building production-ready Stripe subscriptions using Kiro powers'
summary: 'Learn how to build production-ready Stripe subscriptions faster using Kiro Powers. Implement secure payment flows, webhooks, and scalable architecture with AI assistance.'
authors:
  - 'Kalyani Koppisetti'
  - 'Dan Kiuna'
date: '2025-12-04'
topics:
  - 'AWS'
  - 'Partners'
  - 'Billing'
type: 'Blog'
---

Your SaaS application has an opportunity: a new market segment wants premium features, and you can unlock that revenue by adding a "Pro" subscription tier. You need to move fast without compromising code quality.  This scenario is increasingly common, and developers are expected to deliver more with less and in shorter time frames. GenAI coding assistants can be used to improve productivity but most coding assistants struggle to understand the full context.  This results in disjointed code that requires manual integration. You might gain some productivity, but you will spend time cleaning up various components.

In the subscription tier example, teams need to focus on core feature development while also mapping out the complete subscription lifecycle - including scalable payment flows, secure [webhook handlers](https://stripe.com/docs/webhooks), [idempotency](https://stripe.com/docs/api/idempotent_requests) across retry scenarios. You'll need a testing strategy that covers not just happy paths but payment failures, declined cards, and asynchronous payment methods. These decisions shape your architecture and are costly to change later.

This post examines how developers can use [Kiro](https://kiro.dev/), with its newly launched Kiro [power](https://kiro.dev/docs/powers/) from Stripe, to design and implement payments. Kiro is an AI-powered development environment designed to take projects from concept to production through features like specs (artifacts for planning and feature design), hooks (event-driven automations that act like an experienced developer catching issues). Stripe partnered as one of the first launch partners, alongside companies like Figma, Neon, and Postman, to bundle Stripe-specific domain knowledge, best practices, and tooling directly into the IDE.

Powers addresses a fundamental problem with generic AI coding agents: they lack deep workflow knowledge about how to safely implement domain-specific tasks. Overloading an agent with documentation leads to confusion, hallucinations, and inefficiency. Creating separate specialized agents for each workflow creates proliferation and overhead. Powers solves this by dynamically loading only the context required—each power bundles everything an AI agent needs to perform a workflow end-to-end safely and efficiently, designed in collaboration with domain experts.

## How Kiro power simplifies application development with Stripe

When you activate the Stripe power in Kiro, in addition to code generation you're also loading a package that includes [Model Context Protocol (MCP)](https://modelcontextprotocol.io/) servers, steering files with Stripe-specific patterns, and hooks that automate boilerplate tasks as you develop.

Stripe provides extensive functionality through its API by necessity—it handles everything from simple one-time payments to complex subscription billing with metering, invoicing, tax calculation and more. For a straightforward subscription flow, you don't need an AI agent reasoning about every possible Stripe capability. You need it to understand the specific patterns for [Checkout Sessions](https://stripe.com/docs/api/checkout/sessions), [subscription lifecycle management](https://stripe.com/docs/billing/subscriptions/overview), and [webhook event handling](https://stripe.com/docs/webhooks/best-practices) without getting distracted by tangential features.

The Stripe power packages this focused knowledge. When you describe your subscription model—pricing tiers, billing intervals, one-time payment options—the AI agent has immediate access to Stripe-specific patterns like webhook signature verification, proper error handling for payment failures. It knows that webhook endpoints need raw body for signature verification, that Checkout Sessions should be created server-side to prevent client-side price manipulation, and that subscription state should be managed through webhook events rather than polling.

## Building a subscription feature

We'll walk through the Kiro implementation of subscription billing. We'll start by describing what we want to build using this natural language prompt: 'Build a payments page for my SaaS application that has 3 subscription tiers: Basic ($5/month), Advanced ($7/month), Pro ($10/month). Users can cancel anytime. They can also buy a one-time payment valid for 3 months for $4. The solution should be scalable, allow the UI to be hosted on a CDN, and support API-based communication between components.

When we give this prompt to Kiro, it immediately understands the need for a scalable, secure architecture. Instead of generating a monolithic application, Kiro creates a clear separation between a React frontend and a Node.js backend API service. This isn't just an architectural preference—it's a practical necessity for modern SaaS applications that need to scale globally.

Here's how the pieces work together: The frontend consists of static assets (HTML, JavaScript, CSS) that can be served from a CDN, ensuring your users get fast load times whether they're in New York or London. When a user chooses their subscription tier, the React application calls the backend API to create a Stripe Checkout Session. The backend holds the [Stripe secret key](https://stripe.com/docs/keys) and performs the actual API call to Stripe's API, returning a session ID to the frontend. The frontend then redirects to [Stripe Hosted Checkout](https://stripe.com/docs/payments/checkout), where payment collection happens on Stripe's PCI-compliant infrastructure. After payment completion, Stripe redirects the user back to your success URL and sends a webhook event to your backend to confirm the transaction.

This architecture follows best practices for payment handling. Your Stripe secret keys stay safely in the backend, never exposed to the browser. Price manipulation becomes impossible because your backend controls the Checkout Session creation—even if someone tries to hack the JavaScript in their browser, they can't change what your backend sends to Stripe. The frontend can be aggressively cached and distributed globally because it contains no secrets or business logic.  Your backend can scale independently based on actual transaction volume rather than page view traffic.

## Code example: Webhook handler

Now that we’ve looked at the high-level architecture, let’s zoom in to the code Kiro generated for the webhook handler. This function is where your system learns about payment lifecycle events. Stripe sends [webhook events](https://stripe.com/docs/webhooks/stripe-events) for subscription creation, payment success, payment failure, subscription cancellation, and dozens of other scenarios. Your application needs to process these events reliably and securely.

Here's the generated webhook handler:

```javascript
// Webhook handler
app.post('/webhook', express.raw({ type: 'application/json' }), async (req, res) => {
  const sig = req.headers['stripe-signature'];
  let event;
 
  try {
	// Signature verification happens here
	event = stripe.webhooks.constructEvent(
  	req.body,
  	sig,
  	process.env.STRIPE_WEBHOOK_SECRET
	);
  } catch (err) {
	console.error('Webhook signature verification failed:', err.message);
	return res.status(400).send(`Webhook Error: ${err.message}`);
  }
 
  // Handle the event
  switch (event.type) {
	case 'checkout.session.completed':
  	// Payment successful
	case 'customer.subscription.created':
  	// Subscription created
	case 'customer.subscription.deleted':
  	// Subscription cancelled
	// ... more event handlers
  }
 
  res.json({ received: true });
});
```

The implementation details here reflect [Stripe webhook best practices](https://stripe.com/docs/webhooks/best-practices). The endpoint uses [express.raw()](https://expressjs.com/en/api.html#express.raw) middleware instead of the typical JSON body parser. This preserves the raw request body, which is required for signature verification. Stripe signs each webhook with your webhook secret using HMAC, and [stripe.webhooks.constructEvent()](https://stripe.com/docs/webhooks/signatures#verify-official-libraries) recomputes that signature to verify authenticity.

Signature verification protects against forged events. Without it, an attacker who discovers your webhook URL could send fake subscription cancellations, false payment confirmations, or fraudulent refund notifications. Validating the signature before processing any event data ensures that events genuinely originated from Stripe.

The error handling follows a similar pattern. When signature verification fails, the handler immediately returns a 400 status code without processing the event. It logs the error for debugging but doesn't expose detailed error information in the response body beyond what's necessary for Stripe to understand the rejection. This follows the principle of failing fast—don't partially process invalid events, and don't give potential attackers information about why their forged events failed.

The event type routing uses a switch statement to handle different subscription lifecycle events. For production systems, you'd extend this with your specific business logic: granting access when checkout.session.completed fires, provisioning resources when customer.subscription.created occurs, and deprovisioning when customer.subscription.deleted arrives. The generated code provides the skeleton that ensures these events arrive securely and can be processed reliably.

## Conclusion

Stripe power for Kiro goes beyond generic code generation by bundling domain-specific knowledge about Stripe integration patterns, security best practices, and architectural decisions directly into the IDE. The generated code isn't just a basic implementation—it provides a secure, scalable foundation that follows Stripe's best practices. By describing your payment integration needs in natural language, you receive a complete implementation structure. This means you can move from identifying a revenue opportunity to having a working subscription feature in production faster. This shifts your development time from payment infrastructure plumbing to what really matters: customizing the integration for your specific business needs and building the features that differentiate your SaaS product.

For teams looking to quickly monetize new features or add subscription tiers, this approach provides a practical path from concept to production. You get the security, scalability, and reliability needed for production systems, while maintaining the agility to respond quickly to market opportunities.

Check out the demo of Stripe power [here](https://www.youtube.com/watch?v=M46PSAXpMfA). Want to check out Kiro? Sign up [here](https://kiro.dev/pricing/).

For more Stripe learning resources, subscribe to the [Stripe Developers YouTube channel](https://www.youtube.com/stripedevelopers).