Shopify Hydrogen

Overview

Hydrogen is Shopify's official React-based framework for building headless storefronts, built on top of Remix and deployed to Oxygen (Shopify's edge hosting). It provides first-class primitives for the Storefront API — product queries, cart management, customer accounts — alongside Shopify-specific components and hooks that handle caching, streaming, and SEO automatically. This skill covers scaffolding a Hydrogen project, querying the Storefront API, implementing cart functionality, and deploying to Oxygen.

When to Use This Skill

When building a custom Shopify storefront with full design and UX control
When the default Shopify Online Store theme is too limiting for your design requirements
When you need server-side rendering, streaming, and edge-deployed performance
When integrating third-party services (loyalty, CMS, personalization) directly into the storefront
When you want a Shopify-managed backend with a completely custom frontend stack

Prerequisites & Platform Notes

This skill is written for custom/headless storefronts (Node.js, Python, or similar backend). The code examples use TypeScript/Node.js and can be adapted to any stack.

Shopify: Shopify Hydrogen is Shopify's headless framework. MACH/composable patterns apply when using Shopify as the commerce backend with a custom frontend, or when mixing Shopify with other best-of-breed services. WooCommerce: WooCommerce can serve as a headless backend via its REST API and WPGraphQL. These patterns apply when decoupling the frontend from WordPress. Magento: Magento's GraphQL API and PWA Studio support headless architectures. These composable patterns apply to Magento as a backend service in a MACH stack.

You'll need:

Node.js 18+ (or adapt to your backend language)
Redis for caching/queues
An email sending service (SendGrid, AWS SES, or Postmark)
CDN (Cloudflare, CloudFront, or Fastly)

Core Instructions

Scaffold a Hydrogen project

npm create @shopify/hydrogen@latest -- --quickstart
# or with options:
npm create @shopify/hydrogen@latest
# Follow prompts: project name, language (TypeScript), mock shop or real credentials
cd my-hydrogen-store
npm run dev
# http://localhost:3000

The project structure follows Remix file-based routing:

app/
  routes/
    _index.tsx         # Homepage
    products.$handle.tsx  # Product detail page
    collections.$handle.tsx
    cart.tsx
  components/
  lib/
    fragments.ts       # Reusable GraphQL fragments
server.ts              # Hydrogen + Remix entry point

Configure Storefront API credentials

Create a Storefront API token in your Shopify admin under Apps → Develop apps → Create an app → Storefront API.

# .env
SESSION_SECRET="your-session-secret"
PUBLIC_STOREFRONT_API_TOKEN="your-public-token"
PUBLIC_STORE_DOMAIN="your-store.myshopify.com"
PUBLIC_STOREFRONT_API_VERSION="2025-01"

The server.ts wires Hydrogen into Remix:

import {createHydrogenContext} from '@shopify/hydrogen';

const hydrogenContext = createHydrogenContext({
  storefront: {
    apiVersion: env.PUBLIC_STOREFRONT_API_VERSION,
    privateStorefrontToken: env.PRIVATE_STOREFRONT_API_TOKEN,
    publicStorefrontToken: env.PUBLIC_STOREFRONT_API_TOKEN,
    storeDomain: env.PUBLIC_STORE_DOMAIN,
  },
  session: HydrogenSession.init(request, [env.SESSION_SECRET]),
});

Query the Storefront API

Hydrogen provides a storefront.query method with built-in caching policies.

// app/routes/products.$handle.tsx
import {useLoaderData} from '@remix-run/react';
import {json, type LoaderFunctionArgs} from '@shopify/remix-oxygen';

export async function loader({params, context}: LoaderFunctionArgs) {
  const {storefront} = context;
  const {product} = await storefront.query(PRODUCT_QUERY, {
    variables: {handle: params.handle},
    cache: storefront.CacheLong(), // Cache at CDN for 24h
  });

  if (!product) throw new Response('Not Found', {status: 404});
  return json({product});
}

const PRODUCT_QUERY = `#graphql
  query Product($handle: String!) {
    product(handle: $handle) {
      id
      title
      descriptionHtml
      featuredImage { url altText width height }
      variants(first: 20) {
        nodes {
          id
          title
          price { amount currencyCode }
          availableForSale
          selectedOptions { name value }
        }
      }
    }
  }
` as const;

Implement cart with Hydrogen cart utilities

Hydrogen provides server-side cart actions via Remix action functions:

// app/routes/cart.tsx
import {CartForm} from '@shopify/hydrogen';
import type {ActionFunctionArgs} from '@shopify/remix-oxygen';

export async function action({request, context}: ActionFunctionArgs) {
  const {cart} = context;
  const formData = await request.formData();
  const {action, inputs} = CartForm.getFormInput(formData);

  let result;
  switch (action) {
    case CartForm.ACTIONS.LinesAdd:
      result = await cart.addLines(inputs.lines);
      break;
    case CartForm.ACTIONS.LinesUpdate:
      result = await cart.updateLines(inputs.lines);
      break;
    case CartForm.ACTIONS.LinesRemove:
      result = await cart.removeLines(inputs.lineIds);
      break;
    default:
      throw new Error(`Unhandled cart action: ${action}`);
  }

  const headers = cart.setCartId(result.cart.id);
  return json(result, {headers});
}

// Add to cart form component
export function AddToCartButton({variantId}: {variantId: string}) {
  return (
    <CartForm
      route="/cart"
      action={CartForm.ACTIONS.LinesAdd}
      inputs={{lines: [{merchandiseId: variantId, quantity: 1}]}}
    >
      <button type="submit">Add to Cart</button>
    </CartForm>
  );
}

Use Hydrogen caching strategies

Hydrogen exposes named caching strategies that map to CDN cache-control headers:

// Long cache for static catalog data
const {collections} = await storefront.query(COLLECTIONS_QUERY, {
  cache: storefront.CacheLong(), // s-maxage=3600, stale-while-revalidate=82800
});

// Short cache for inventory-sensitive data
const {product} = await storefront.query(PRODUCT_WITH_INVENTORY, {
  cache: storefront.CacheShort(), // s-maxage=1, stale-while-revalidate=9
});

// No cache for personalized/cart data
const {customer} = await storefront.query(CUSTOMER_QUERY, {
  cache: storefront.CacheNone(),
});

// Custom strategy
const {data} = await storefront.query(QUERY, {
  cache: storefront.CacheCustom({
    mode: 'public',
    maxAge: 600,
    staleWhileRevalidate: 3000,
  }),
});

Deploy to Oxygen

npm install -g @shopify/cli
shopify hydrogen deploy
# Creates a deployment in your Shopify admin under Online Store → Themes → Headless

For CI/CD, use the GitHub Action:

# .github/workflows/oxygen.yml
- uses: Shopify/hydrogen-action@v1
  with:
    shop: ${{ secrets.SHOPIFY_SHOP_DOMAIN }}
    token: ${{ secrets.SHOPIFY_CLI_TOKEN }}

Examples

Collection page with filtering and sorting

// app/routes/collections.$handle.tsx
export async function loader({params, request, context}: LoaderFunctionArgs) {
  const {storefront} = context;
  const url = new URL(request.url);
  const sortKey = url.searchParams.get('sort') as ProductCollectionSortKeys | null;

  const {collection} = await storefront.query(COLLECTION_QUERY, {
    variables: {
      handle: params.handle,
      first: 24,
      sortKey: sortKey ?? 'BEST_SELLING',
      reverse: sortKey === 'PRICE' ? false : true,
    },
    cache: storefront.CacheShort(),
  });

  return json({collection});
}

const COLLECTION_QUERY = `#graphql
  query Collection(
    $handle: String!
    $first: Int
    $sortKey: ProductCollectionSortKeys
    $reverse: Boolean
  ) {
    collection(handle: $handle) {
      id
      title
      description
      image { url altText }
      products(first: $first, sortKey: $sortKey, reverse: $reverse) {
        nodes {
          id
          title
          handle
          priceRange { minVariantPrice { amount currencyCode } }
          featuredImage { url altText }
        }
        pageInfo { hasNextPage endCursor }
      }
    }
  }
` as const;

Customer authentication with new Customer Account API

// Hydrogen supports the new Customer Account API (OAuth-based)
// app/lib/customer-account.server.ts
export async function loader({context}: LoaderFunctionArgs) {
  const {customerAccount} = context;
  const isLoggedIn = await customerAccount.isLoggedIn();

  if (!isLoggedIn) {
    return redirect('/account/login');
  }

  const {data} = await customerAccount.query(`#graphql
    query Customer {
      customer {
        id
        firstName
        lastName
        emailAddress { emailAddress }
        orders(first: 10) {
          nodes {
            id
            number
            processedAt
            financialStatus
            totalPrice { amount currencyCode }
          }
        }
      }
    }
  `);

  return json({customer: data.customer});
}

Best Practices

Use storefront.CacheLong() for catalog data — product and collection data rarely changes; long cache TTLs dramatically improve TTFB on Oxygen's edge network
Colocate GraphQL queries with routes — define as const fragment strings in the same file as the loader; this keeps data requirements visible and enables TypeScript inference
Use Hydrogen's <Image> and <Money> components — they handle Shopify CDN image optimization URLs and currency formatting automatically
Leverage Remix defer + Suspense for non-critical data — render the product immediately and stream recommendations or reviews with defer()
Keep cart state server-side via cookies — Hydrogen's cart utilities store the cart ID in a signed cookie; avoid client-only cart state that breaks SSR
Use the Storefront API's @inContext directive — pass language and country context to get localized prices and translated content per request
Pin the Storefront API version in .env — Shopify deprecates old API versions; explicit pinning prevents surprise breakage on API updates

Common Pitfalls

Problem	Solution
"Storefront API token not authorized"	Ensure the token has `unauthenticated_read_*` scopes; private tokens are only for server-side requests
Cart state lost between page navigations	Store cart ID in the session cookie using `cart.setCartId()`; never store cart ID in component state
Images not optimized on Oxygen	Use Hydrogen's `<Image>` component or the `getImageData()` helper to append Shopify CDN transform params
TypeScript errors on GraphQL queries	Run `npm run codegen` to regenerate types after changing queries; queries must be tagged `as const`
Deployment fails with "missing environment variables"	Oxygen env vars must be added in the Shopify admin under the Hydrogen deployment settings, not just in `.env`

Related Skills

@saleor-development
@jamstack-storefront
@composable-commerce
@pwa-storefront
@commerce-api-gateway

shopify-hydrogen