wdk-checkout

Headless, framework-free WDK checkout SDK — self-custodial USDt payments for ecommerce. Powers the WooCommerce WDK Pay gateway and works standalone in any storefront. The customer pays directly from their own wallet to the merchant; the SDK never custodies funds.

npm install @wdk-starter/wdk-checkout
# ethers is an optional peer — only needed for the /x402 and /subscriptions subpaths:
npm install ethers

Mount the widget

import { mountCheckout } from '@wdk-starter/wdk-checkout'

const teardown = mountCheckout(document.getElementById('checkout')!, {
  intent: {
    orderId: 1, orderKey: 'wc_abc', amount: '19.99', amountBase: '19990000',
    decimals: 6, tokenAddress: '0x…', tokenSymbol: 'USDt',
    chainId: 1, chainName: 'Ethereum', chainKey: 'ethereum',
    receivingAddress: '0x…', reference: '0x…', status: 'pending',
    expiresAt: Math.floor(Date.now() / 1000) + 1800,
    // optional fiat display:
    displayTotal: '19.99', currency: 'USD',
  },
  endpoints: { confirm: '/confirm', status: '/status' },
  nonce: '…', returnUrl: '/order-received',
  // optional: re-skin to your storefront
  theme: { accent: '#0D9488', surface: '#0B1F1C', onSurface: '#E6FFFA', radius: '10px' },
})

The widget is fully themeable via a CheckoutTheme palette (injected as CSS variables). Connect a wallet and pay, or pay manually and confirm by tx hash.

Subpath modules

| Import | What it is | |---|---| | @wdk-starter/wdk-checkout | the checkout widget (mountCheckout, payIntent, DEFAULT_CHECKOUT_THEME, types) | | @wdk-starter/wdk-checkout/x402 | x402 facilitator — verify/settle per-request EIP-3009 payments (charge bots/agents) | | @wdk-starter/wdk-checkout/pricing | fiat display + exact base-unit conversion, pluggable RateSource | | @wdk-starter/wdk-checkout/swap | swap-to-settle plan math (pay any token, merchant receives USDt) | | @wdk-starter/wdk-checkout/subscriptions | recurring payments as per-period EIP-3009 authorizations | | @wdk-starter/wdk-checkout/lightning | BOLT11 invoice + poll-to-settlement (LightningProvider) | | @wdk-starter/wdk-checkout/react | optional React/RN adapter — <WdkCheckout> drop-in + useWdkPayment headless hook (typed CheckoutErrors + state machine). react is an optional peer. |

The ecommerce-rail modules (pricing/swap/subscriptions/lightning) are config-driven — you supply the rate feed / DEX quote / Lightning endpoint; no keys are hard-coded. x402 and subscriptions use ethers (optional peer).

Docs

Full documentation, the WooCommerce plugin, architecture, security model, and copy-paste rail wiring live in the repository — see docs/ECOMMERCE_RAILS.md.

License

MIT. Built with Tether WDK. A community reference implementation; not an official Tether product.