---
name: ck-shopify
description: Build Shopify apps, extensions, and themes with Shopify CLI. Use for GraphQL/REST Admin API, Polaris UI components, Liquid templates, checkout customization, webhooks, and billing integration.
---

# Shopify Development

Build Shopify apps, extensions, and themes for the Shopify platform.

## When to Use

- Building Shopify apps (OAuth, Admin API, webhooks, billing)
- Creating checkout UI, admin, or POS extensions
- Developing Liquid-based themes
- Integrating with GraphQL Admin API
- Setting up Shopify CLI workflows

## Don't Use When

- Building for non-Shopify e-commerce platforms
- Simple storefront customizations that don't need an app or extension

## Quick Start

```bash
npm install -g @shopify/cli@latest

# App development
shopify app init
shopify app dev        # Starts local server with tunnel
shopify app deploy

# Theme development
shopify theme init
shopify theme dev      # Preview at localhost:9292
shopify theme push --development
```

## Build Decision Guide

| Build | When |
|-------|------|
| **App** | External service integration, multi-store functionality, complex logic, charging for features |
| **Extension** | Customize checkout, extend admin pages, POS actions, discount/shipping rules |
| **Theme** | Custom storefront design, brand-specific layouts, product/collection pages |

## Essential Patterns

**GraphQL Product Query:**
```graphql
query GetProducts($first: Int!) {
  products(first: $first) {
    edges {
      node { id title handle variants(first: 5) { edges { node { id price } } } }
    }
    pageInfo { hasNextPage endCursor }
  }
}
```

**Checkout Extension (React):**
```javascript
import { reactExtension, BlockStack, TextField } from '@shopify/ui-extensions-react/checkout';
export default reactExtension('purchase.checkout.block.render', () => <Extension />);
```

**Liquid Product Display:**
```liquid
{% for product in collection.products %}
  <h3>{{ product.title }}</h3>
  <p>{{ product.price | money }}</p>
{% endfor %}
```

## Best Practices

- Prefer GraphQL over REST for new development
- Store API credentials in environment variables — never hardcode
- Verify webhook HMAC signatures before processing
- Request minimal OAuth scopes
- Use bulk operations for large datasets
- Implement exponential backoff for rate limit errors

## Reference Files

- `references/app-development.md` — OAuth, APIs, webhooks, billing
- `references/extensions.md` — Checkout, Admin, POS, Functions
- `references/themes.md` — Liquid, sections, deployment

## Resources

- Shopify Dev Docs: https://shopify.dev/docs
- GraphQL API: https://shopify.dev/docs/api/admin-graphql
- Polaris: https://polaris.shopify.com
- Current API version: 2025-01