Payment Plugins

Payment plugins integrate payment service providers with Unchained Engine. Built-in plugins are IPlugin objects that self-register their adapters, webhook routes, and database modules — register them via a preset or individually with pluginRegistry.register(...) before startPlatform().

Adapter Key	Description	Integration Type	Preset
shop.unchained.payment.stripe	Stripe Payments	Server-side	all
shop.unchained.datatrans	Datatrans (Swiss PSP)	Hosted checkout	all
shop.unchained.payment.saferpay	Worldline Saferpay	Hosted checkout	all
shop.unchained.payment.postfinance-checkout	PostFinance Checkout	Hosted checkout	all
shop.unchained.payment.payrexx	Payrexx (TWINT, PostFinance)	Hosted checkout	all
shop.unchained.payment.cryptopay	Self-hosted crypto payments	Server-side	crypto, all
shop.unchained.apple-iap	Apple In-App Purchase	Native SDK	all
shop.unchained.invoice	Pay-per-invoice (B2B)	Offline	base, all
shop.unchained.invoice-prepaid	Prepayment invoice	Offline	all

Checkout Flow

All gateway plugins (Stripe, Datatrans, Saferpay, PostFinance Checkout, Payrexx, Cryptopay) share the same flow. The provider pages only document the provider-specific parts.

1. Get the order payment id of the active cart:

query {
  me {
    cart {
      payment {
        _id
      }
    }
  }
}

2. Sign the payment — returns a provider-specific JSON string (client secret, redirect URL, payment addresses, ...):

mutation {
  signPaymentProviderForCheckout(
    orderPaymentId: "order-payment-id"
    transactionContext: {} # provider-specific options
  )
}

3. Process the payment client-side (redirect, SDK, or wallet transfer — see the provider page).

4. Webhook completes the checkout. The payment provider calls the plugin's auto-registered webhook route; Unchained validates the transaction and checks out the cart server-side.

5. Fallback: client-side checkout. If the webhook has not completed the checkout (e.g. it failed or is still in flight), call checkoutCart yourself with the provider-specific paymentContext:

mutation {
  checkoutCart(paymentContext: { transactionId: "..." }) {
    _id
    status
  }
}

This gives Unchained a second chance to process and settle the payment.

Creating Custom Payment Plugins

See Custom Payment Plugins and the registerPaymentProvider factory.