Shopify Development Skill

• Building Shopify apps or extensions
• Creating checkout/admin/POS UI customizations
• Developing themes with Liquid templating
• Integrating with Shopify GraphQL or REST APIs
• Implementing webhooks or billing
• Working with metafields or Shopify Functions

ROUTING: What to Build

Shopify CLI Commands

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shopify app init          # Create new app
shopify app dev           # Start dev server with tunnel
shopify app deploy        # Build and upload to Shopify
`Generate extension:`
shopify app generate extension --type checkout_ui_extension
shopify app generate extension --type admin_action
shopify app generate extension --type admin_block
shopify app generate extension --type pos_ui_extension
shopify app generate extension --type function
`Theme development:`
shopify theme init        # Create new theme
shopify theme dev         # Start local preview at localhost:9292
shopify theme pull --live # Pull live theme
shopify theme push --development  # Push to dev theme

Access Scopes

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[access_scopes]
scopes = "read_products,write_products,read_orders,write_orders,read_customers"

• read_products, write_products - Product catalog access
• read_orders, write_orders - Order management
• read_customers, write_customers - Customer data
• read_inventory, write_inventory - Stock levels
• read_fulfillments, write_fulfillments - Order fulfillment

GraphQL Patterns (Validated against API 2026-01)

Query Products

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query GetProducts($first: Int!, $query: String) {
  products(first: $first, query: $query) {
    edges {
      node {
        id
        title
        handle
        status
        variants(first: 5) {
          edges {
            node {
              id
              price
              inventoryQuantity
            }
          }
        }
      }
    }
    pageInfo {
      hasNextPage
      endCursor
    }
  }
}
`### Query Orders`
query GetOrders($first: Int!) {
  orders(first: $first) {
    edges {
      node {
        id
        name
        createdAt
        displayFinancialStatus
        totalPriceSet {
          shopMoney {
            amount
            currencyCode
          }
        }
      }
    }
  }
}
`### Set Metafields`
mutation SetMetafields($metafields: [MetafieldsSetInput!]!) {
  metafieldsSet(metafields: $metafields) {
    metafields {
      id
      namespace
      key
      value
    }
    userErrors {
      field
      message
    }
  }
}
`Variables example:`
{
  "metafields": [
    {
      "ownerId": "gid://shopify/Product/123",
      "namespace": "custom",
      "key": "care_instructions",
      "value": "Handle with care",
      "type": "single_line_text_field"
    }
  ]
}

Checkout Extension Example

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import {
  reactExtension,
  BlockStack,
  TextField,
  Checkbox,
  useApplyAttributeChange,
} from "@shopify/ui-extensions-react/checkout";

export default reactExtension("purchase.checkout.block.render", () => (
  <GiftMessage />
));

function GiftMessage() {
  const [isGift, setIsGift] = useState(false);
  const [message, setMessage] = useState("");
  const applyAttributeChange = useApplyAttributeChange();

  useEffect(() => {
    if (isGift && message) {
      applyAttributeChange({
        type: "updateAttribute",
        key: "gift_message",
        value: message,
      });
    }
  }, [isGift, message]);

  return (
    <BlockStack spacing="loose">
      <Checkbox checked={isGift} onChange={setIsGift}>
        This is a gift
      </Checkbox>
      {isGift && (
        <TextField
          label="Gift Message"
          value={message}
          onChange={setMessage}
          multiline={3}
        />
      )}
    </BlockStack>
  );
}

Liquid Template Example

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{% comment %} Product Card Snippet {% endcomment %}
<div>
  <a href="{{ product.url }}">
    {% if product.featured_image %}
      <img
        src="{{ product.featured_image | img_url: 'medium' }}"
        alt="{{ product.title | escape }}"
        loading="lazy"
      >
    {% endif %}
    <h3>{{ product.title }}</h3>
    <p>{{ product.price | money }}</p>
    {% if product.compare_at_price > product.price %}
      <p>Sale</p>
    {% endif %}
  </a>
</div>

Webhook Configuration

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[webhooks]
api_version = "2026-01"

[[webhooks.subscriptions]]
topics = ["orders/create", "orders/updated"]
uri = "/webhooks/orders"

[[webhooks.subscriptions]]
topics = ["products/update"]
uri = "/webhooks/products"

# GDPR mandatory webhooks (required for app approval)
[webhooks.privacy_compliance]
customer_data_request_url = "/webhooks/gdpr/data-request"
customer_deletion_url = "/webhooks/gdpr/customer-deletion"
shop_deletion_url = "/webhooks/gdpr/shop-deletion"

Best Practices

API Usage

• Use GraphQL over REST for new development
• Request only fields you need (reduces query cost)
• Implement cursor-based pagination with pageInfo.endCursor
• Use bulk operations for processing more than 250 items
• Handle rate limits with exponential backoff

Security

• Store API credentials in environment variables
• Always verify webhook HMAC signatures before processing
• Validate OAuth state parameter to prevent CSRF
• Request minimal access scopes
• Use session tokens for embedded apps

Performance

• Cache API responses when data doesn't change frequently
• Use lazy loading in extensions
• Optimize images in themes using img_url filter
• Monitor GraphQL query costs via response headers

Troubleshooting

Reference Files

• references/app-development.md - OAuth authentication flow, GraphQL mutations for products/orders/billing, webhook handlers, billing API integration
• references/extensions.md - Checkout UI components, Admin UI extensions, POS extensions, Shopify Functions for discounts/payment/delivery
• references/themes.md - Liquid syntax reference, theme directory structure, sections and snippets, common patterns

Scripts

• scripts/shopify_init.py - Interactive project scaffolding. Run: python scripts/shopify_init.py
• scripts/shopify_graphql.py - GraphQL utilities with query templates, pagination, rate limiting. Import: from shopify_graphql import ShopifyGraphQL

Official Documentation Links

• Shopify Developer Docs: https://shopify.dev/docs
• GraphQL Admin API Reference: https://shopify.dev/docs/api/admin-graphql
• Shopify CLI Reference: https://shopify.dev/docs/api/shopify-cli
• Polaris Design System: https://polaris.shopify.com