Shopify Development Skill

Use this skill when the user asks about:

• 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

IF user wants to integrate external services OR build merchant tools OR charge for features: → Build an App (see references/app-development.md)

IF user wants to customize checkout OR add admin UI OR create POS actions OR implement discount rules: → Build an Extension (see references/extensions.md)

IF user wants to customize storefront design OR modify product/collection pages: → Build a Theme (see references/themes.md)

IF user needs both backend logic AND storefront UI: → Build App + Theme Extension combination

Shopify CLI Commands

Install CLI:

npm install -g @shopify/cli@latest

Create and run app:

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

Configure in shopify.app.toml:

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

Common scopes:

• 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

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

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

{%