cathrynlavery/shopify-developer-skill

Overview

This skill provides comprehensive Shopify development guidance for theme architecture, Liquid templating, Admin and Storefront APIs, metafields/metaobjects, checkout extensibility, Shopify Functions, webhooks, and platform limits. It’s designed for implementing or debugging app/theme work, API integrations, checkout customizations, and data modeling. Use it as the coordination hub and consult the referenced files for implementation details.

How this skill works

The skill inspects API conventions, authentication patterns, and core workflows to produce actionable recommendations and code patterns. It validates that you use quarterly API versions, prefer GraphQL, paginate with cursors, and apply idempotent mutation patterns. For larger exports/imports it recommends bulk operations and for checkout changes it separates UI extensions from pricing/fulfillment logic handled by Functions.

When to use it

• Implementing or debugging theme changes, Liquid templates, and OS 2.0 layouts.
• Building or integrating with Admin or Storefront GraphQL APIs and metafields/metaobjects.
• Designing checkout customizations using Checkout UI Extensions and Shopify Functions.
• Migrating Scripts, REST-based integrations, or upgrading API versions before deprecation.
• Creating reliable webhook handlers and respecting platform rate limits and retry semantics.

Best practices

• Always include the API version in endpoints and update quarterly (e.g., 2026-01).
• Prefer GraphQL for new work; use REST only for maintenance scenarios.
• Paginate with cursor-based first/after and budget GraphQL cost points.
• Use idempotency keys and idempotent mutations for retry-safe writes.
• Keep Shopify Functions minimal to meet strict runtime and WASM constraints.
• Validate theme edits in draft first and avoid hand-editing settings_data.json.

Example use cases

• Create a new product import using Admin bulk operations to avoid throttling.
• Add typed metafields and metaobjects, then render values in Liquid with .value.
• Build a post-purchase upsell using Checkout UI Extensions and a pricing Function.
• Migrate legacy Scripts to Shopify Functions and confirm runtime limits.
• Implement webhook processing with HMAC verification and idempotent handlers.