E-commerce platform Shopify is overhauling its storefront architecture to return to simpler, highly readable code, finding an unexpected partner in AI agents. The company is introducing a new base theme designed to replace Horizon, its current JSON-heavy default template. Built primarily with HTML and Shopify’s block-based Liquid templating language, the upcoming theme boasts 93 percent fewer lines of code than its predecessor, making it significantly easier for both humans and machines to parse.
According to Shopify product director for storefronts Ben Sehl, the shift is largely driven by the rapid adoption of the company’s AI assistant, Shopify Sidekick. Data from the company indicates that 20 percent of its merchants are using Sidekick to edit their themes, generating 25 million edits within a single year. As AI agents handle more web design tasks, developers discovered that automated models function best on clean, transparent web standards rather than dense, deeply nested configuration files.
“Every leading model already understands HTML. It is expressive, local, and token-efficient,” Sehl wrote in a post on X.
From Clean Templates to Complex JSON
A decade ago, setting up an online storefront on Shopify relied on basic, highly accessible templates that novice web developers could easily modify with third-party starter kits. Over time, as the platform introduced the Online Store Editor, merchants gained granular control over every page component, button, and layout element. This flexibility carried a hidden architectural cost.
To accommodate the myriad of visual choices and user customizations, template configurations were serialized into JSON format. While this gave store owners deep customization options, it obscured the underlying structure. Developers could no longer understand a page simply by opening and reading a single file. As Sehl noted, templates ceased to function as a great developer surface and instead became an auto-saved output with a constrained vocabulary.
When Shopify introduced its Sidekick AI assistant, the friction of these complex configurations became glaringly apparent. AI agents, much like human programmers, require clean code, explicit contracts, and clear feedback loops to operate efficiently. This realization prompted the engineering team to rethink storefront architecture from the ground up, establishing human-readable and AI-palatable standards as core principles while committing to maintain existing Liquid themes via a forever API.
Rebuilding Liquid for Humans and Machines
To build the new base theme, Shopify updated its Liquid template language with a new parser and syntax capable of executing advanced back-end instructions. Despite these powerful capabilities beneath the hood, the code exposed to users consists of composable, typed blocks that sit alongside ordinary HTML files inside a clean directory structure.
The updated architecture introduces several primitives that simplify storefront creation:
- Composable block tags: Nested parameters describe page components that developers can supply with values, configurations, and overrides without needing a virtual DOM.
- Partial primitives: Allows specific regions of a storefront page to update dynamically without requiring a full-page re-render.
- Standard actions: Event triggers that manage common site functions, such as updating a shopping cart, which removed thousands of lines of reactivity code found in Horizon.
In addition to these structural updates, Shopify implemented 20 strict rules governing contract validation, structure, file-size limits, and nesting complexity. Liquid now also supports advanced logical capabilities, including Boolean expressions, infix operators with precedence, and literal arrays and objects, with future support planned for the Tailwind CSS framework.
Broader Industry Shifts Toward Readable Code
Shopify’s pivot highlights a broader realization among developers and artificial intelligence researchers: large language models perform better when trained and prompted on transparent, human-readable prose and web standards rather than highly dense, symbolic domain-specific languages. While industries spent years favoring compact formats like JSON for APIs and configurations, platforms are rediscovering the value of expressive formats like XML and HTML for prompting and generation tasks.
By streamlining its architecture, Shopify aims to lower the barrier to entry for merchant customization. Instead of anticipating exact component counts within a rigid settings-driven configuration, store owners can rely on flexible HTML structures when building out their digital storefronts.
Shopify is expected to roll out further developer documentation and guidelines through its official developer forums as the unnamed theme moves closer to general release. Readers and merchants looking for technical updates can monitor Shopify’s developer portal and official announcements for upcoming preview builds and migration timelines. What are your thoughts on this return to simpler code? Join the discussion in the comments below and share this article with fellow developers.
Worth a look