Shopify Developer Reference
Comprehensive reference for professional Shopify development - API version 2026-01.
Quick Reference
Item Value
API version 2026-01 (stable)
GraphQL Admin POST https://{store}.myshopify.com/admin/api/2026-01/graphql.json
Storefront API POST https://{store}.myshopify.com/api/2026-01/graphql.json
Ajax API (theme) /cart.js , /cart/add.js , /cart/change.js
CLI install npm install -g @shopify/cli
Theme dev shopify theme dev --store {store}.myshopify.com
App dev shopify app dev
Deploy shopify app deploy
Docs shopify.dev
Choose Your Path
Read the reference file(s) that match your task:
Liquid templating - writing or debugging .liquid files:
-
references/liquid-syntax.md - Tags, control flow, iteration, whitespace, LiquidDoc
-
references/liquid-filters.md - All filter categories with examples
-
references/liquid-objects.md - Product, collection, cart, customer, and global objects
Theme development - building or customising themes:
- references/theme-development.md - OS 2.0 architecture, sections, blocks, JSON templates, settings schema
API integration - fetching or modifying data programmatically:
-
references/api-admin.md - GraphQL Admin API (primary), REST (legacy), OAuth, webhooks, rate limiting
-
references/api-storefront.md - Storefront API, Ajax API, cart operations
App development - building Shopify apps:
- references/app-development.md - Shopify CLI, extensions, Polaris Web Components, App Bridge
Serverless logic - custom business rules:
- references/functions.md - Shopify Functions (replacing Scripts), Rust/JS targets, deployment
Headless commerce - custom storefronts:
- references/hydrogen.md - Hydrogen framework, React Router 7, Storefront API integration
Optimisation and troubleshooting:
-
references/performance.md - Images, JS, CSS, fonts, Liquid, Core Web Vitals
-
references/debugging.md - Liquid errors, API errors, cart issues, webhook failures
Deprecation Notices
Deprecated Replacement Deadline
Shopify Scripts Shopify Functions August 2025 (migration), sundown TBD
checkout.liquid Checkout Extensibility August 2024 (Plus), done
REST Admin API GraphQL Admin API Active deprecation (no removal date yet)
Legacy custom apps New auth model January 2025 (done)
Polaris React Polaris Web Components Active migration
Remix (app framework) React Router 7 Hydrogen 2025.5.0+
Liquid Essentials
Three syntax types:
{{ product.title | upcase }} {# Output with filter #} {% if product.available %}In stock{% endif %} {# Logic tag #} {% assign sale = product.price | times: 0.8 %} {# Assignment #} {%- if condition -%}Stripped whitespace{%- endif -%}
Key patterns:
{% for product in collection.products limit: 5 %} {% render 'product-card', product: product %} {% endfor %}
{% paginate collection.products by 12 %} {% for product in paginate.collection.products %}...{% endfor %} {{ paginate | default_pagination }} {% endpaginate %}
API Essentials
// GraphQL Admin - always use GraphQL over REST
const response = await fetch(
https://${store}.myshopify.com/admin/api/2026-01/graphql.json,
{
method: 'POST',
headers: {
'X-Shopify-Access-Token': accessToken,
'Content-Type': 'application/json',
},
body: JSON.stringify({ query, variables }),
}
);
const { data, errors } = await response.json();
if (errors) throw new Error(errors[0].message);
// Ajax API (theme-only cart operations) fetch('/cart/add.js', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ id: variantId, quantity: 1 }), });
Reference Files
File Lines Coverage
liquid-syntax.md ~600 Tags, control flow, iteration, variables, whitespace, LiquidDoc
liquid-filters.md ~870 String, numeric, array, Shopify-specific, date, URL, colour filters
liquid-objects.md ~695 All Shopify objects: product, variant, collection, cart, customer, order, etc.
theme-development.md ~1200 File structure, JSON templates, sections, blocks, settings schema, layout
api-admin.md ~595 GraphQL queries/mutations, REST (legacy), OAuth, webhooks, rate limiting
api-storefront.md ~235 Storefront API, Ajax API, cart operations, Customer Account API
app-development.md ~760 CLI, app architecture, extensions, Polaris Web Components, deployment
functions.md ~300 Function types, Rust/JS targets, CLI workflow, Scripts migration
hydrogen.md ~375 Setup, routing, data loading, Storefront API, deployment
performance.md ~605 Images, JS, CSS, fonts, Liquid, third-party scripts, Core Web Vitals
debugging.md ~650 Liquid, JavaScript, API, cart, webhook, theme editor troubleshooting