Add Payment Handler

Step 1: Install the Prism package

Detect the package manager from the lockfile and use the correct command:

npm install @financedistrict/saleor-prism-payment

Step 2: Update the SDK configuration

Read the existing agentic-commerce config file and add the Prism handler:

import { createAgenticCommerce } from "@financedistrict/saleor-agentic-commerce-nextjs"
import { PrismPaymentHandler } from "@financedistrict/saleor-prism-payment"

export const agenticCommerce = createAgenticCommerce({
  // ... existing config ...
  paymentHandlers: [
    new PrismPaymentHandler({
      apiUrl: process.env.PRISM_API_URL,
      apiKey: process.env.PRISM_API_KEY,
    }),
  ],
})

Important: Don't overwrite the existing config — only add the paymentHandlers array and the import. Keep all existing properties.

Step 3: Add environment variables

Append to .env.local and .env.example (if it exists):

# ─── Prism Payment (Stablecoin via x402) ────────────────
PRISM_API_URL=https://prism-gw.fd.xyz    # Prism Gateway URL
PRISM_API_KEY=                             # Your Prism API key (get from developers.fd.xyz/prism)

Step 4: Verify

Show the developer:

1. What was changed (the config file diff).
2. The new env vars that need values.
3. How to get a Prism API key: Visit https://developers.fd.xyz/prism
4. How agents will pay:
   • Agent discovers payment methods via GET /api/ucp → sees xyz.fd.prism_payment in payment_handlers
   • Agent creates checkout, then submits a signed EIP-3009 authorization to the complete endpoint
   • Prism settles the stablecoin transfer on-chain
   • Order is confirmed

Other Payment Handlers

If the developer asks about other payment handlers:

• Stripe — Not yet available. The SDK's PaymentHandlerAdapter interface supports any payment provider. A Stripe adapter could be built by implementing prepareCheckoutPayment() and settlePayment().
• Custom — Point to the PaymentHandlerAdapter interface in @financedistrict/saleor-agentic-commerce-core. It requires: id, getUcpDiscoveryHandlers(), getAcpDiscoveryHandlers(), prepareCheckoutPayment(), settlePayment().