Introducing PayKit — A Unified Payment SDK

Payment integration is fragmented. Every provider has its own SDK, its own patterns, its own way of modeling charges, refunds, and webhooks. Building a production payment system means either lock-in to a single provider or maintaining multiple integrations in parallel.

PayKit solves this with a unified adapter pattern.

The Problem

Modern applications need payment flexibility:

• Geographic reach — Stripe dominates the US, Razorpay owns India, PayPal is global but has different fee structures
• Compliance — Some regions require local processors
• Cost optimization — Fees vary wildly between providers
• Failover — If your primary gateway goes down, you need a backup

The traditional approach is multi-SDK hell:

// Before: managing 3 different SDKs
import Stripe from 'stripe';
import Razorpay from 'razorpay';
import { PayPalHttpClient } from '@paypal/checkout-server-sdk';
 
// Three different initialization patterns
const stripe = new Stripe(process.env.STRIPE_SECRET_KEY);
const razorpay = new Razorpay({ key_id: '...', key_secret: '...' });
const paypal = new PayPalHttpClient(environment);
 
// Three different ways to create a charge
const stripeCharge = await stripe.charges.create({ ... });
const razorpayOrder = await razorpay.orders.create({ ... });
const paypalOrder = await paypal.execute(request);

Every method call, every webhook handler, every error code is provider-specific.

The Solution

PayKit provides one SDK, multiple backends:

import { PayKit } from '@squaredr/paykit';
 
const paykit = new PayKit({
  provider: 'stripe', // or 'razorpay', 'paypal', etc.
  apiKey: process.env.PAYMENT_KEY,
});
 
const charge = await paykit.charge.create({
  amount: 5000,
  currency: 'USD',
  source: token,
});

Switch providers by changing one line:

const paykit = new PayKit({
  provider: 'razorpay', // That's it.
  apiKey: process.env.RAZORPAY_KEY,
});

How It Works

PayKit uses the adapter pattern — a thin abstraction layer that translates your calls into provider-specific API requests.

Each adapter implements the same interface (IPaymentAdapter) but talks to its provider's native SDK under the hood.

What's Supported

Currently shipping adapters for:

• Stripe — Full support (charges, refunds, customers, webhooks)
• Razorpay — Full support
• PayPal — Full support
• Square — Planned

All adapters are free and open source (MIT license).

Smart Routing

The adapter pattern unlocks powerful routing:

import { PaymentRouter } from '@squaredr/paykit'
 
const router = new PaymentRouter({
  routes: [
    { currency: 'INR', adapter: razorpay },
    { currency: 'USD', adapter: stripe },
  ],
  default: stripe,
})
 
const charge = await router.createCharge({
  amount: 50000,
  currency: 'INR', // → routes to Razorpay
})

PayKit automatically routes charges to the optimal provider based on currency, region, or explicit override — and you can preview routing decisions with router.resolveAdapter() before creating a charge. See the multi-provider routing guide for details.

Get Started

npm install @squaredr/paykit

Check the docs for full integration guides and API reference.

PayKit is MIT licensed and built in public. Contributions welcome at github.com/SquaredR98/paykit.