steelyard

The Steelyard SDK front door. Define commerce once, serve it everywhere, let buyers buy. One install, one import.

npm install steelyard

Define once, serve everywhere

import { defineCommerce, serveCommerce } from "steelyard";

const manifest = defineCommerce({
  identity: { name: "My Shop", domain: "shop.example", currencies: ["USD"] },
  offers: [
    { id: "tee", title: "T-Shirt", availability: "in_stock",
      pricing: [{ kind: "one_time", amount: 2500, currency: "USD" }] }
  ]
});

serveCommerce(manifest).listen(3000);
// Live now from one manifest:
//   GET /.well-known/commerce.json   GET /commerce/products   POST /mcp
//   GET /acp/feed                    GET /.well-known/ucp + /api/catalog/*

curl localhost:3000/.well-known/commerce.json

serveCommerce is read-only by default (no PSP needed). It returns a Node Server you can .listen(), or use createCommerceReadHandler(manifest) to mount the surfaces inside your own server.

What's re-exported

This package re-exports the symbols 90% of integrators need:

| Need | Symbols | |------|---------| | Define schemas | defineCommerce, types Manifest Offer Price PurchaseIntent | | Serve | serveCommerce, createCommerceReadHandler | | Per-protocol handlers | createMcpServer createMcpHttpHandler createUcpHandler buildUcpDiscovery createAcpFeedHandler buildAcpFeed createCommerceManifestHandler createHttpApiHandler | | Checkout + PSP | createCheckoutServer, stripePsp, referencePsp | | Payment instruments | vaultedCard, stripeSpt, referenceMandate, x402Payments, x402Fetch | | Paid HTTP resources | x402Paywall, exactUsdc | | Policy | PolicyEngine, createPolicyEngine | | Buy | Wallet, Steelyard / connect |

Power users

This is a curated front door, not the whole surface. For anything not above, import the specific package directly — e.g. steelyard/protocol/ucp, steelyard/buyer/vault, steelyard/merchant, steelyard/x402, steelyard/core. The umbrella never hides them; it just gives you a shorter path to the common case.