Shopify Development

This skill provides comprehensive guidance for building on the Shopify platform, including apps, extensions, themes, and API integrations.

When to Use This Skill

Use this skill when you need to:

• Build Shopify apps (public or custom)
• Create checkout, admin, or POS UI extensions
• Develop themes using Liquid templating
• Integrate with Shopify APIs (GraphQL Admin API, REST API, Storefront API)
• Implement Shopify Functions (discounts, payments, delivery, validation)
• Build headless storefronts with Hydrogen
• Configure webhooks and metafields
• Use Shopify CLI for development workflows

Core Platform Components

1. Shopify CLI

Installation:

npm install -g @shopify/cli@latest

Essential Commands:

• shopify app init - Create new app
• shopify app dev - Start local development server
• shopify app deploy - Deploy app to Shopify
• shopify app generate extension - Add extension to app
• shopify theme dev - Preview theme locally
• shopify theme pull/push - Sync theme files

For detailed CLI reference, see reference/cli-commands.md

2. GraphQL Admin API (Recommended)

Primary API for new development. Efficient, type-safe, flexible.

Endpoint:

https://{shop-name}.myshopify.com/admin/api/2025-01/graphql.json

Authentication:

headers: {
  'X-Shopify-Access-Token': 'your-access-token',
  'Content-Type': 'application/json'
}

Common Operations:

• Query products, orders, customers, inventory
• Create/update/delete resources via mutations
• Bulk operations for large datasets
• Real-time data with subscriptions

For comprehensive GraphQL reference, see reference/graphql-admin-api.md

3. REST Admin API (Maintenance Mode)

Use only for legacy systems. Shopify recommends GraphQL for all new development.

Base URL:

https://{shop-name}.myshopify.com/admin/api/2025-01/{resource}.json

Rate Limits:

• Standard: 2 requests/second
• Plus: 4 requests/second

4. UI Frameworks

Polaris (React)

Design system for consistent Shopify UI:

npm install @shopify/polaris

Polaris Web Components

Framework-agnostic components:

<script src="https://cdn.shopify.com/shopifycloud/polaris.js"></script>

Extension Types

Checkout UI Extensions

Customize checkout experience with native-rendered components.

Generate:

shopify app generate extension --type checkout_ui_extension

Configuration: shopify.extension.toml

Common Components: View, BlockStack, InlineLayout, Button, TextField, Checkbox, Banner

For detailed extension reference, see reference/ui-extensions.md

Admin UI Extensions

Extend Shopify admin interface.

Types:

• App blocks (embedded in native pages)
• App overlays (modal experiences)
• Links (product/collection/order pages)

POS Extensions

Customize Point of Sale experience.

Types:

• Smart Grid Tiles (quick access actions)
• Modals (dialogs and forms)
• Cart modifications (custom discounts/line items)

Post-Purchase Extensions

Upsell offers after checkout completion.

Target: purchase.thank-you.block.render

Customer Account UI Extensions

Customize post-purchase account pages.

Targets: Account overview, order status/index

Shopify Functions

Serverless backend customization running on Shopify infrastructure.

Function Types:

• Discounts: Cart, product, shipping, order discounts
• Payment customization: Hide/rename/reorder payment methods
• Delivery customization: Custom shipping options
• Order routing: Fulfillment location rules
• Validation: Cart and checkout business rules
• Fulfillment constraints: Bundle shipping rules

Languages: JavaScript, Rust, AssemblyScript

Generate:

shopify app generate extension --type function

Theme Development

Liquid Templating

Core Concepts:

• Objects: {{ product.title }} - Output dynamic content
• Filters: {{ product.price | money }} - Transform data
• Tags: {% if %} {% for %} {% case %} - Control flow

Common Objects:

• product - Product data
• collection - Collection data
• cart - Shopping cart
• customer - Customer account
• shop - Store information

Architecture:

• Layouts: Base templates
• Templates: Page structures
• Sections: Reusable content blocks (Online Store 2.0)
• Snippets: Smaller components

Development:

shopify theme dev    # Local preview
shopify theme pull   # Download from store
shopify theme push   # Upload to store

Authentication & Security

OAuth 2.0 Flow

For public apps accessing merchant stores:

1. Redirect merchant to authorization URL
2. Merchant approves access
3. Receive authorization code
4. Exchange code for access token
5. Store token securely

Access Scopes

Request minimum permissions needed:

• read_products - View products
• write_products - Modify products
• read_orders - View orders
• write_orders - Modify orders

Full scope list: https://shopify.dev/api/usage/access-scopes

Session Tokens

For embedded apps in Shopify admin using App Bridge.

Webhooks

Real-time event notifications from Shopify.

Configuration: shopify.app.toml

Common Topics:

• orders/create, orders/updated, orders/paid
• products/create, products/update, products/delete
• customers/create, customers/update
• app/uninstalled

GDPR Mandatory Webhooks:

• customers/data_request
• customers/redact
• shop/redact

Metafields

Custom data storage for extending Shopify resources.

Owners: Products, variants, customers, orders, collections, shop

Types: text, number, date, URL, JSON, file_reference

Access: Admin API, Storefront API, Liquid templates

Best Practices

Performance

• Use GraphQL instead of REST for efficiency
• Request only needed fields in queries
• Implement pagination for large datasets
• Use bulk operations for batch processing
• Respect rate limits (cost-based for GraphQL)

User Experience

• Follow Polaris design guidelines
• Implement loading states
• Provide clear error messages
• Support keyboard navigation
• Test across devices

Security

• Store API credentials securely
• Use environment variables for tokens
• Implement webhook verification
• Follow OAuth best practices
• Request minimal access scopes

Code Quality

• Use TypeScript for type safety
• Write comprehensive error handling
• Implement retry logic with exponential backoff
• Log errors for debugging
• Keep dependencies updated

Testing

• Use development stores for testing
• Test across different store plans
• Verify webhook handling
• Test app uninstall flow
• Validate GDPR compliance

Development Workflow

1. Initialize App:

   shopify app init

2. Configure Access Scopes: Edit shopify.app.toml:

   [access_scopes]
   scopes = "read_products,write_products"

3. Start Development Server:

   shopify app dev

4. Generate Extensions:

   shopify app generate extension

5. Test in Development Store: Install app on test store

6. Deploy to Production:

   shopify app deploy

Common Patterns

Fetch Products (GraphQL)

query {
  products(first: 10) {
    edges {
      node {
        id
        title
        handle
        variants(first: 5) {
          edges {
            node {
              id
              price
              inventoryQuantity
            }
          }
        }
      }
    }
    pageInfo {
      hasNextPage
      endCursor
    }
  }
}

Create Product (GraphQL)

mutation {
  productCreate(input: {
    title: "New Product"
    productType: "Clothing"
    variants: [{
      price: "29.99"
      sku: "SKU123"
    }]
  }) {
    product {
      id
      title
    }
    userErrors {
      field
      message
    }
  }
}

Checkout Extension (React)

import { useState } from 'react';
import {
  render,
  BlockStack,
  TextField,
  Checkbox,
  useApi
} from '@shopify/ui-extensions-react/checkout';

function Extension() {
  const { extensionPoint } = useApi();
  const [checked, setChecked] = useState(false);

  return (
    <BlockStack>
      <TextField label="Gift Message" />
      <Checkbox checked={checked} onChange={setChecked}>
        This is a gift
      </Checkbox>
    </BlockStack>
  );
}

render('Checkout::Dynamic::Render', () => <Extension />);

Resources

Documentation

• Official docs: https://shopify.dev/docs
• GraphQL API: https://shopify.dev/docs/api/admin-graphql
• Shopify CLI: https://shopify.dev/docs/api/shopify-cli
• Polaris: https://polaris.shopify.com

Tools

• GraphiQL Explorer: Built into Shopify admin
• Shopify CLI: Development workflow
• Partner Dashboard: App management
• Development stores: Free testing environments

Learning

• Shopify Developer Changelog: API updates and deprecations
• Built for Shopify: Quality program for apps
• Community forums: Help and discussions

Reference Documentation

This skill includes detailed reference documentation:

• GraphQL Admin API Reference - Comprehensive API guide
• Shopify CLI Commands - Complete CLI reference
• UI Extensions - Extension types and components

Troubleshooting

Common Issues

Rate Limit Errors:

• Monitor X-Shopify-Shop-Api-Call-Limit header
• Implement exponential backoff
• Use bulk operations for large datasets

Authentication Failures:

• Verify access token is valid
• Check required scopes are granted
• Ensure OAuth flow completed correctly

Webhook Not Receiving Events:

• Verify webhook URL is accessible
• Check webhook signature validation
• Review webhook logs in Partner Dashboard

Extension Not Appearing:

• Verify extension target is correct
• Check extension is published
• Ensure app is installed on store

Version Management

Shopify uses quarterly API versioning (YYYY-MM format):

• Current: 2025-01
• Each version supported for 12 months
• Test updates before quarterly releases
• Use version-specific endpoints

App Distribution

Custom Apps

Single merchant installation, no review required.

Public Apps

App Store listing with Shopify review:

• Follow app requirements
• Complete Built for Shopify criteria
• Define pricing model
• Submit for review

Note: This skill covers the Shopify platform as of January 2025. Always refer to official Shopify documentation for the latest updates and API versions.