Build Shopify apps, extensions, themes using GraphQL Admin API, Shopify CLI, Polaris UI, and Liquid.

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: Create and run app: Generate extension: Theme development: Access Scopes Configure in shopify.app.toml : 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 Orders Set Metafields Variables example: Checkout Extension Example Liquid Template Example Webhook Configuration In shopify.app.toml : 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 IF you see rate limit errors: → Implement exponential backoff retry logic → Switch to bulk operations for large datasets → Monitor X Shopify Shop Api Call Limit header IF authentication fails: → Verify the access token is still valid → Check that all required scopes were granted → Ensure OAuth flow completed successfully IF extension is not appearing: → Verify the extension target is correct → Check that extension is published via shopify app deploy → Confirm the app is installed on the test store IF webhook is not receiving events: → Verify the webhook URL is publicly accessible → Check HMAC signature validation logic → Review webhook logs in Partner Dashboard IF GraphQL query fails: → Validate query against schema (use GraphiQL explorer) → Check for deprecated fields in error message → Verify you have required access scopes Reference Files For detailed implementation guides, read these 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 API Version: 2026 01 (quarterly releases, 12 month deprecation window) When to Use This skill is applicable to execute the workflow or actions described in the overview. Limitations Use this skill only when the task clearly matches the scope described above. Do not treat the output as a substitute for environment specific validation, testing, or expert review. Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.

shopify-development