Building a custom checkout shouldn't slow you down. a55 CheckoutOS gives SaaS companies modular APIs for identity, payments, and subscriptions so you can launch faster, scale smarter, and keep more of what you earn.
Rigid billing systems make growth harder than it needs to be. a55 Subscriptions gives you the flexibility to build and scale recurring revenue without draining engineering resources or creating billing headaches. Focus on your product, not your payments.
Explore subscriptions
a55's fully composable checkout connects the pieces you need, and nothing you don't. Choose from modular APIs for identity, payments, fraud, tax, and subscriptions, all built for SaaS speed and scale.
See the platform
Use only what you need. Plug in, scale up, stay flexible.
Skip long replatforms. a55's pre-built APIs and developer-first docs get you live in days, not quarters.
Elastic infrastructure supports spikes, growth, and global reach without re-architecting your stack.
a55 CheckoutOS gives developers clean, modern APIs that integrate fast and scale seamlessly, backed by robust SDKs, docs, and real-time data hooks.
Promise-based API with full TypeScript support
Node.js, Python, Ruby, PHP, Java, and more
Real-time notifications for your backend systems
import { a55Checkout } from '@a55/sdk'
const checkout = a55Checkout.init({
publicKey: 'pk_live_...',
locale: 'en-US',
})
// Create a subscription checkout
const session = await checkout.createSession({
mode: 'subscription',
lineItems: [{
price: 'price_pro_monthly',
quantity: 1,
}],
successUrl: '/dashboard?welcome=true',
cancelUrl: '/pricing',
})
// Redirect to hosted checkout
await checkout.redirectToCheckout(session.id)Move faster and scale confidently with a55's composable checkout platform.