Shopify Overview

The Shopify admin is where merchants manage products, orders, customers, discounts, inventory, markets, apps and settings. It is itself an app platform: an embedded app is a page inside the admin. Products are published to sales channels: the Online Store channel (the theme-rendered storefront), Point of Sale for physical retail, the Headless channel for custom storefronts, Shop, social and marketplace channels, and AI channels. Developers mostly meet two of them: Online Store (themes) and Headless (the Storefront API).

Shopify announces its product changes twice a year in an Edition, and developers announce theirs continuously in the developer changelog at shopify.dev/changelog. The two recent editions are Winter '26 "Renaissance" (2025-12-10) and Spring '26 "Everywhere" (2026-06-17). There is no Summer '26 edition. For build work the changelog and the API version table below are the authoritative sources; editions are marketing summaries.

Shopify’s APIs are versioned by quarter. A version is named YYYY-MM, released at 17:00 UTC on the first day of the quarter, and supported for at least 12 months, which gives at least 9 months of overlap with its successor. The status on 2026-10-27 was:

There are three kinds of version: stable, release candidate (published on the date the previous quarter’s version goes stable, so integrations can test early) and unstable (updated continuously). A request for a version that is no longer accessible is not rejected: it falls forward to the oldest accessible stable version and the response header X-Shopify-API-Version shows which version actually served it. Deprecated fields are removed in a later release; the 2026-10 schema marks automaticDiscounts as removed in 2027-01 and currentBulkOperation as superseded by bulkOperations. The versioned APIs are the GraphQL Admin API, Storefront API, Customer Account API, the Function APIs, Webhooks, Events and the Partner API. Some surfaces are not versioned and can change at any time: Liquid, the Ajax API, the App Bridge APIs, the Web Pixels API, OAuth endpoints, Customer Privacy API and Storefront Web Components. Libraries follow their own major versions (Hydrogen, Hydrogen React, the app libraries).

Source: Shopify docs: API versioning

A theme controls how the Online Store looks and behaves. Since Online Store 2.0 (2021) a theme is a folder with a fixed layout: layout/ (page shells such as theme.liquid), templates/ (mostly JSON files that list which sections a page contains), sections/, blocks/, snippets/, assets/, config/ (settings_schema.json and settings_data.json) and locales/. Pages are composed from sections that merchants add, remove and reorder in the theme editor; sections contain blocks; theme blocks are reusable and can nest. Logic is written in Liquid, an open source template language created at Shopify and maintained as a Ruby gem (5.14.0 on 2026-10-27), extended by Shopify with tags such as schema, render, content_for and section, and with 155 filters, 33 tags and 142 objects in the reference snapshot used for this subsection. Liquid itself is not versioned: it evolves continuously.

Three reference themes exist. Skeleton is the minimal starting point installed by shopify theme init. Dawn (16.0.0) is the long-standing Online Store 2.0 reference. Horizon (4.3.0) is the newer reference built around theme blocks. The Shopify Theme Store accepts only themes built on Skeleton, and requires a minimum average Lighthouse performance score of 60. The Reference Themes page compares them.

Themes cannot run server-side code of their own. Anything that needs a database or a secret is done by an app, reached either through the storefront (an app block or an app proxy) or by writing data into Shopify objects the theme reads (metafields and metaobjects, see Metafields and Metaobjects).

An app is a web application that integrates with Shopify through APIs. It authenticates to a shop, receives events as webhooks, calls the Admin GraphQL API and, if embedded, renders its interface inside the Shopify admin with App Bridge and the Polaris web components. Two kinds exist.

The Shopify CLI scaffolds an app with shopify app init (the --template option accepts reactRouter or none; the older Remix template is legacy), links it to the Dev Dashboard and runs a development tunnel with shopify app dev. The REST Admin API is legacy since 2024-10-01 and new public apps must use GraphQL; no REST shutdown date has been published, so existing REST integrations keep running while new work targets GraphQL. The Admin GraphQL API page covers cost-based rate limits, pagination and the migration from REST.

An extension is a unit of code that lives in an app project, is described by a shopify.extension.toml file, and is deployed with shopify app deploy so that Shopify runs it. The CLI’s template catalogue (shopify app generate extension --template <id>) lists 81 templates on 2026-10-27, which group into these families:

A headless storefront replaces the theme with your own front end, which reads catalogue data and manages carts through the Storefront API and signs customers in through the Customer Account API. The Storefront API accepts a public access token for browser and mobile use, a private token for server-side use, and (since recent API versions) tokenless access for a subset of data. The @inContext directive selects country and language, and in 2026-10 also a channel.

Hydrogen changed shape with the 2026-10 release (generally available 2026-10-14): it is now a framework-agnostic toolkit with a core entry point and React and Vue bindings, with a React Router starter for Oxygen and a Next.js starter, rather than the full-stack Remix and React Router framework that earlier releases (2026-04 and before) were. That earlier framework is documented as Legacy Hydrogen. Oxygen is Shopify’s hosting for storefronts and is included at no extra charge on the paid plans. Checkout is always Shopify-hosted, so headless projects still customise it through checkout extensions. The Storefront API documentation does not declare any maintenance mode; what is deprecated is the old Liquid-theme customer account system (legacy customer accounts, deprecated 2026-02-26) in favour of the Customer Account API.

The roast date badge is a Liquid snippet that reads a product metafield (namespace custom, key roast_date) and renders nothing when it is empty. The leading doc tag documents the snippet’s parameters, which Theme Check uses to validate calls.

It is saved as snippets/roast-date-badge.liquid, called from the product section with {% render 'roast-date-badge', product: product %}, and the translation key is added to locales/en.default.json:

Source: Shopify docs: Liquid doc tag and Shopify docs: Snippets

This example was run: it was added to a copy of the Skeleton theme and shopify theme check reported "40 files inspected with no offenses found". Without the translation key the same check reported a TranslationKeyExists error, and without the render call an OrphanedSnippet warning. The first run of Theme Check downloads the Liquid reference data and needs network access; later runs use a local cache. Rendering the snippet on a real storefront needs a shop and was not done.

An app reads the active Pocket Coffee products and their variants with the Admin GraphQL API. It is sent to https://<shop>.myshopify.com/admin/api/2026-10/graphql.json with the header X-Shopify-Access-Token. The query is paginated with first and after; the pageInfo fields tell the client whether to request another page.

Source: Shopify docs: Admin GraphQL products query

The query was validated against the public Admin 2026-10 schema (downloaded anonymously from shopify.dev) with the graphql library and reported valid. It was not sent to a shop because that needs an access token.

A headless storefront reads one product in the Spanish market. @inContext selects the country and language, and the metafield alias exposes the roast date. A public Storefront token (or tokenless access for the data that allows it) is sent in the header X-Shopify-Storefront-Access-Token.

Source: Shopify docs: Storefront API product query and Shopify docs: inContext directive

This query validated against the Storefront 2026-10 schema (421 types) and was not sent to a shop.

Every CLI-built app has a shopify.app.toml at its root. This minimal one declares the app, its scopes, its redirect URL and the webhooks: one ordinary subscription and the three compliance topics that every App Store app must answer. The client_id is a placeholder; the real value comes from the Dev Dashboard. The domain example.invalid is reserved and never resolves.

Source: Shopify docs: App configuration and Shopify docs: Privacy law compliance

Run offline, shopify app build --no-input accepted this file and printed "pocket-coffee-app built!". Changing embedded = true to the string "yes" made it fail with "[embedded]: Value must be Boolean", and removing [auth] produced "[auth]: Required". Creating the app from the template (shopify app init), linking it and deploying all require a logged-in Shopify account and were not executed.