Shopify Development Expert

Purpose

Provide comprehensive, accurate guidance for building on Shopify's platform based on 24+ official documentation files. Cover all aspects of app development, theme customization, API integration, checkout extensions, and e-commerce features.

Documentation Coverage

Full access to official Shopify documentation (when available):

•Location: docs/shopify/
•Files: 25 markdown files
•Coverage: Complete API reference, guides, best practices, and implementation patterns

Note: Documentation must be pulled separately:

bash

pipx install docpull
docpull https://shopify.dev/docs -o .claude/skills/shopify/docs

Major Areas:

•GraphQL Admin API (products, orders, customers, inventory)
•Storefront API (cart, checkout, customer accounts)
•REST Admin API (legacy support)
•App development (authentication, webhooks, extensions)
•Theme development (Liquid, sections, blocks)
•Headless commerce (Hydrogen, Oxygen)
•Checkout customization (UI extensions, validation)
•Shopify Functions (discounts, delivery, payments)
•POS extensions (in-person sales)
•Subscriptions and selling plans
•Metafields and custom data
•Shopify Flow automation
•CLI and development tools
•Privacy and compliance
•Performance optimization

When to Use

Invoke when user mentions:

•Platform: Shopify, e-commerce, online store, merchant
•APIs: GraphQL, REST, Storefront API, Admin API
•Products: product management, collections, variants, inventory
•Orders: order processing, fulfillment, shipping
•Customers: customer data, accounts, authentication
•Checkout: checkout customization, payment methods, delivery options
•Themes: Liquid templates, theme development, sections, blocks
•Apps: app development, extensions, webhooks, OAuth
•Headless: Hydrogen, React, headless commerce, Oxygen
•Functions: Shopify Functions, custom logic, discounts
•Subscriptions: recurring billing, selling plans, subscriptions
•Tools: Shopify CLI, development workflow
•POS: point of sale, retail, in-person payments

How to Use Documentation

When answering questions:

•

Search for specific topics:

bash

# Use Grep to find relevant docs
grep -r "checkout" .claude/skills/shopify/docs/ --include="*.md"

•

Read specific documentation:

bash

# API docs
cat .claude/skills/shopify/docs/shopify/api-admin-graphql.md
cat .claude/skills/shopify/docs/shopify/api-storefront.md

•

Find implementation guides:

bash

# List all guides
ls .claude/skills/shopify/docs/shopify/

Core Authentication

OAuth 2.0 Flow

javascript

// Redirect to Shopify OAuth
const authUrl = `https://${shop}/admin/oauth/authorize?` +
  `client_id=${process.env.SHOPIFY_API_KEY}&` +
  `scope=read_products,write_products&` +
  `redirect_uri=${redirectUri}&` +
  `state=${nonce}`;

// Exchange code for access token
const response = await fetch(
  `https://${shop}/admin/oauth/access_token`,
  {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      client_id: process.env.SHOPIFY_API_KEY,
      client_secret: process.env.SHOPIFY_API_SECRET,
      code
    })
  }
);

const { access_token } = await response.json();

Session Tokens (Modern Embedded Apps)

javascript

import { shopifyApi } from '@shopify/shopify-api';

const shopify = shopifyApi({
  apiKey: process.env.SHOPIFY_API_KEY,
  apiSecretKey: process.env.SHOPIFY_API_SECRET,
  scopes: ['read_products', 'write_products'],
  hostName: process.env.HOST,
  isEmbeddedApp: true,
});

GraphQL Admin API

Query Products

graphql

query {
  products(first: 10) {
    edges {
      node {
        id
        title
        handle
        priceRange {
          minVariantPrice {
            amount
            currencyCode
          }
        }
        variants(first: 5) {
          edges {
            node {
              id
              sku
              inventoryQuantity
            }
          }
        }
      }
    }
  }
}

Create Product

graphql

mutation {
  productCreate(input: {
    title: "New Product"
    vendor: "My Store"
    productType: "Apparel"
    variants: [{
      price: "29.99"
      sku: "PROD-001"
    }]
  }) {
    product {
      id
      title
    }
    userErrors {
      field
      message
    }
  }
}

Fetch Orders

graphql

query {
  orders(first: 25, query: "fulfillment_status:unfulfilled") {
    edges {
      node {
        id
        name
        createdAt
        totalPriceSet {
          shopMoney {
            amount
            currencyCode
          }
        }
        customer {
          email
        }
        lineItems(first: 10) {
          edges {
            node {
              title
              quantity
            }
          }
        }
      }
    }
  }
}

Storefront API

Create Cart

graphql

mutation {
  cartCreate(input: {
    lines: [{
      merchandiseId: "gid://shopify/ProductVariant/123"
      quantity: 1
    }]
  }) {
    cart {
      id
      checkoutUrl
      cost {
        totalAmount {
          amount
          currencyCode
        }
      }
    }
  }
}

Update Cart

graphql

mutation {
  cartLinesUpdate(
    cartId: "gid://shopify/Cart/xyz"
    lines: [{
      id: "gid://shopify/CartLine/abc"
      quantity: 2
    }]
  ) {
    cart {
      id
      lines(first: 10) {
        edges {
          node {
            quantity
          }
        }
      }
    }
  }
}

Webhooks

Setup Webhook

javascript

// Register webhook via API
const webhook = await shopify.webhooks.register({
  topic: 'ORDERS_CREATE',
  address: 'https://your-app.com/webhooks/orders-create',
  format: 'json'
});

Verify Webhook

javascript

import crypto from 'crypto';

function verifyWebhook(body, hmacHeader, secret) {
  const hash = crypto
    .createHmac('sha256', secret)
    .update(body, 'utf8')
    .digest('base64');

  return hash === hmacHeader;
}

// In webhook handler
app.post('/webhooks/orders-create', async (req, res) => {
  const hmac = req.headers['x-shopify-hmac-sha256'];
  const body = await req.text();

  if (!verifyWebhook(body, hmac, process.env.SHOPIFY_API_SECRET)) {
    return res.status(401).send('Invalid HMAC');
  }

  const order = JSON.parse(body);
  // Process order...

  res.status(200).send('OK');
});

Liquid Templates

Basic Liquid

liquid

<!-- Output product title -->
{{ product.title }}

<!-- Conditional logic -->
{% if product.available %}
  <button>Add to Cart</button>
{% else %}
  <span>Sold Out</span>
{% endif %}

<!-- Loop through variants -->
{% for variant in product.variants %}
  <option value="{{ variant.id }}">
    {{ variant.title }} - {{ variant.price | money }}
  </option>
{% endfor %}

Custom Section

liquid

{% schema %}
{
  "name": "Featured Product",
  "settings": [
    {
      "type": "product",
      "id": "product",
      "label": "Product"
    }
  ]
}
{% endschema %}

{% if section.settings.product %}
  {% assign product = section.settings.product %}
  <div class="featured-product">
    <img src="{{ product.featured_image | img_url: '500x' }}" alt="{{ product.title }}">
    <h2>{{ product.title }}</h2>
    <p>{{ product.price | money }}</p>
  </div>
{% endif %}

Shopify Functions

Discount Function

javascript

// Function to apply volume discount
export default (input) => {
  const quantity = input.cart.lines.reduce((sum, line) => sum + line.quantity, 0);

  let discountPercentage = 0;
  if (quantity >= 10) discountPercentage = 20;
  else if (quantity >= 5) discountPercentage = 10;

  if (discountPercentage > 0) {
    return {
      discounts: [{
        message: `${discountPercentage}% volume discount`,
        targets: [{
          orderSubtotal: {
            excludedVariantIds: []
          }
        }],
        value: {
          percentage: {
            value: discountPercentage.toString()
          }
        }
      }]
    };
  }

  return { discounts: [] };
};

Delivery Customization

javascript

// Hide specific delivery options
export default (input) => {
  const operations = [];

  // Hide express shipping for orders under $100
  const cartTotal = parseFloat(input.cart.cost.subtotalAmount.amount);

  if (cartTotal < 100) {
    const expressOptions = input.cart.deliveryGroups[0].deliveryOptions
      .filter(option => option.title.toLowerCase().includes('express'));

    expressOptions.forEach(option => {
      operations.push({
        hide: {
          deliveryOptionHandle: option.handle
        }
      });
    });
  }

  return { operations };
};

Hydrogen (Headless Commerce)

Product Page

typescript

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

export async function loader({params, context}: LoaderFunctionArgs) {
  const {product} = await context.storefront.query(PRODUCT_QUERY, {
    variables: {handle: params.handle},
  });

  return json({product});
}

export default function Product() {
  const {product} = useLoaderData<typeof loader>();

  return (
    <div>
      <h1>{product.title}</h1>
      <img src={product.featuredImage.url} alt={product.title} />
      <p>{product.description}</p>
      <AddToCartButton productId={product.id} />
    </div>
  );
}

const PRODUCT_QUERY = `#graphql
  query Product($handle: String!) {
    product(handle: $handle) {
      id
      title
      description
      featuredImage {
        url
        altText
      }
      variants(first: 10) {
        nodes {
          id
          price {
            amount
            currencyCode
          }
        }
      }
    }
  }
`;

Shopify CLI

Common Commands

bash

# Create new app
shopify app init

# Start development server
shopify app dev

# Deploy app
shopify app deploy

# Create extension
shopify app generate extension

# Create theme
shopify theme init

# Serve theme locally
shopify theme dev --store=your-store.myshopify.com

# Push theme
shopify theme push

# Pull theme
shopify theme pull

Testing

Test Stores

•Create Partner account: https://partners.shopify.com
•Create development store
•Install your app
•Test features

Test Data

javascript

// Create test product
const product = await shopify.rest.Product.save({
  session,
  title: "Test Product",
  body_html: "<strong>Test description</strong>",
  vendor: "Test Vendor",
  product_type: "Test Type",
  variants: [{
    price: "19.99",
    sku: "TEST-001"
  }]
});

// Create test order
const order = await shopify.rest.Order.save({
  session,
  line_items: [{
    variant_id: 123456789,
    quantity: 1
  }],
  customer: {
    email: "test@example.com"
  }
});

Security Best Practices

•
API Keys:
- •Store in environment variables
- •Never commit to version control
- •Use separate keys per environment
- •Rotate if compromised
•
Webhooks:
- •ALWAYS verify HMAC signatures
- •Use HTTPS endpoints only
- •Return 200 immediately
- •Process async
•
Access Scopes:
- •Request minimal scopes
- •Document why each scope is needed
- •Review periodically
•
Rate Limits:
- •Respect API rate limits
- •Implement exponential backoff
- •Monitor API usage

Common Errors

API Authentication

•Invalid access token - Check token is valid and has correct scopes
•Shop not found - Verify shop domain format
•Missing access token - Include X-Shopify-Access-Token header

GraphQL Errors

•User errors - Check userErrors field in response
•Throttled - Reduce request rate
•Field not found - Verify API version supports field

Webhook Issues

•Invalid HMAC - Check webhook secret and verification logic
•Delivery failed - Ensure endpoint returns 200 within timeout
•Not receiving webhooks - Check webhook registration and endpoint URL

Resources

•Dashboard: https://partners.shopify.com
•Documentation: https://shopify.dev
•GraphiQL Admin: https://shopify.dev/docs/apps/tools/graphiql-admin-api
•Community: https://community.shopify.com
•Status: https://www.shopifystatus.com

Documentation Quick Reference

Need to find something specific?

bash

# Search all docs
grep -r "search term" .claude/skills/shopify/docs/

# Find specific topics
ls .claude/skills/shopify/docs/shopify/

# Read specific guide
cat .claude/skills/shopify/docs/shopify/webhooks.md

Common doc files:

•api-admin-graphql.md - GraphQL Admin API
•api-storefront.md - Storefront API
•authentication.md - OAuth and auth flows
•webhooks.md - Webhook handling
•apps.md - App development
•themes.md - Theme development
•liquid.md - Liquid reference
•hydrogen.md - Headless commerce
•checkout.md - Checkout customization
•functions.md - Shopify Functions
•cli.md - CLI commands