SKILL.md
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Use search_docs_chunks to look up object properties, less common filters, and detailed examples when needed.
Theme Architecture
Key principles: focus on generating snippets, blocks, and sections; users may create templates using the theme editor
Directory structure
.
├── assets # Static assets (CSS, JS, images, fonts)
├── blocks # Reusable, nestable, customizable components
├── config # Global theme settings and customization options
├── layout # Top-level wrappers for pages
├── locales # Translation files for internationalization
├── sections # Modular full-width page components
├── snippets # Reusable Liquid code or HTML fragments
└── templates # JSON or Liquid files defining page structure
#### sections
.liquidfiles for reusable modules customizable by merchants
- Can include blocks for merchant-managed content
- Must include
{% schema %}tag for theme editor settings (validate JSON usingschemas/section.json)
- Use
{{ block.shopify_attributes }}on block wrapper elements for theme editor drag-and-drop
#### blocks
.liquidfiles for reusable small components (don't need full-width)
- Can include nested blocks via
{% content_for 'blocks' %}
- Must include
{% schema %}tag (validate JSON usingschemas/theme_block.json)
- Must have
{% doc %}tag when statically rendered via{% content_for 'block', id: '42', type: 'block_name' %}
#### snippets
- Reusable code fragments rendered via
{% render 'snippet', param: value %}
- Accept parameters for dynamic behavior
- Must have the
{% doc %}tag as the header
#### layout
- Defines overall HTML structure (
,), wraps templates
- Must include
{{ content_for_header }}inand{{ content_for_layout }}for page content
#### config
config/settings_schema.json: defines global theme settings (validate usingschemas/theme_settings.json)
config/settings_data.json: holds data for those settings
#### locales
- Translation files by language code (e.g.,
en.default.json,fr.json)
- Access via
{{ 'key' | t }}filter (validate usingschemas/translations.json)
#### templates
- JSON or
.liquidfiles defining which sections/blocks appear on each page type
CSS & JavaScript
- Write per-component CSS/JS using
{% stylesheet %}and{% javascript %}tags
- These tags are only supported in
snippets/,blocks/, andsections/
- Liquid is NOT rendered inside
{% stylesheet %}or{% javascript %}tags
LiquidDoc
Snippets and static blocks must include a LiquidDoc header:
{% doc %}
@param {image} image - The image to render
@param {string} [url] - Optional destination URL
@example
{% render 'image', image: product.featured_image %}
{% enddoc %}
Schema tag good practices
Single CSS property — use CSS variables:
**Multiple CSS properties** — use CSS classes:
Liquid reference
Delimiters
{{ ... }}/{{- ... -}}: Output (dashes trim whitespace)
{% ... %}/{%- ... -%}: Logic tags (dashes trim whitespace)
Gotchas
- No parentheses in conditions — use nested
iffor complex logic
- No ternary operator — always use
{% if %}
containsonly works with strings, not objects in arrays
forloops limited to 50 iterations — use{% paginate %}for larger arrays
rendercreates isolated scope — pass variables as parameters
Variables
{% assign my_var = 'value' %}
{% capture my_var %}computed {{ content }}{% endcapture %}
Key Shopify tags
content_for — render theme blocks:
{% content_for 'blocks' %}
{% content_for 'block', type: 'slide', id: 'slide-1' %}
form — requires a type parameter:
{% form 'contact' %}
{{ form.errors | default_errors }}
Submit
{% endform %}
Types: product, contact, customer_login, create_customer, customer_address, cart, localization, new_comment, recover_customer_password, reset_customer_password, activate_customer_password, guest_login, currency, customer, storefront_password
render — isolated scope, pass variables:
{% render 'card', product: product, show_price: true %}
{% render 'tag' for product.tags as tag %}
paginate — required for arrays >50 items:
{% paginate collection.products by 12 %}
{% for product in collection.products %}
{{ product.title }}
{% endfor %}
{{ paginate | default_pagination }}
{% endpaginate %}
liquid — multi-statement block:
{% liquid
assign featured = collection.products | where: 'available', true
echo featured | size
%}
Other Shopify tags:
{% schema %}— JSON settings for theme editor
{% section 'name' %}/{% sections 'group' %}— render sections
{% stylesheet %}/{% javascript %}— per-component CSS/JS
{% style %}— CSS that live-updates in editor for color settings
{% layout 'name' %}— set layout template
{% doc %}— LiquidDoc header
forloop object (inside for loops): forloop.index, forloop.index0, forloop.first, forloop.last, forloop.length
Common filters
Images (use image_tag/image_url, not deprecated img_tag/img_url):
{{ product.featured_image | image_url: width: 400, height: 400 | image_tag }}
{{ image | image_url: width: 800 | image_tag: class: 'responsive' }}
Array: {{ array | where: 'available', true }}, {{ array | map: 'title' }}, {{ array | reject: 'field', 'value' }}, {{ array | first }}, {{ array | last }}, {{ array | sort: 'field' }}, {{ array | size }}, {{ array | join: ', ' }}, {{ array | uniq }}, compact, concat, find, find_index, has, reverse, sort_natural, sum
String: split, append, prepend, remove, replace, strip, truncate, upcase, downcase, capitalize, escape, handleize, url_encode, url_decode, camelize, slice, strip_html, newline_to_br, pluralize
Math: plus, minus, times, divided_by, modulo, round, ceil, floor, abs, at_least, at_most
Money: {{ product.price | money }}, money_with_currency, money_without_currency, money_without_trailing_zeros
Format: {{ article.published_at | date: '%B %d, %Y' }}, {{ product | json }}, structured_data
Color: color_to_hex, color_to_hsl, color_to_rgb, color_to_oklch, color_darken, color_lighten, color_mix, color_modify, color_saturate, color_brightness
HTML: link_to, script_tag, stylesheet_tag, time_tag, preload_tag, placeholder_svg_tag, inline_asset_content
Hosted file: asset_url, file_url, global_asset_url, shopify_asset_url
Other: {{ 'key' | t }}, {{ variable | default: fallback }}, default_errors, default_pagination, metafield_tag, metafield_text, font_face, font_url, payment_button
Global objects
collections, pages, all_products, articles, blogs, cart, customer, images, linklists, localization, metaobjects, request, routes, shop, theme, settings, template, content_for_header, content_for_layout, canonical_url, page_title, page_description, handle
Page-specific objects (product, collection, article, blog, order, search, etc.) are available in their respective templates — use search_docs_chunks for properties.
Translation rules
- Every user-facing text must use
{{ 'key' | t }}, updatelocales/en.default.json
- Hierarchical snake_case keys (max 3 levels), sentence case, variable interpolation:
{{ 'key' | t: var: value }}
Example: block
{% doc %}
Renders a text block with configurable style and alignment.
@example
{% content_for 'block', type: 'text', id: 'text' %}
{% enddoc %}
{% stylesheet %}
.text { text-align: var(--text-align); }
.text--title { font-size: 2rem; font-weight: 700; }
{% endstylesheet %}
{% schema %}
{
"name": "t:general.text",
"settings": [
{ "type": "text", "id": "text", "label": "t:labels.text", "default": "Text" },
{ "type": "select", "id": "text_style", "label": "t:labels.text_style", "options": [
{ "value": "text--title", "label": "t:options.text_style.title" },
{ "value": "text--normal", "label": "t:options.text_style.normal" }
], "default": "text--title" },
{ "type": "text_alignment", "id": "alignment", "label": "t:labels.alignment", "default": "left" }
],
"presets": [{ "name": "t:general.text" }]
}
{% endschema %}
Design requirements
- Modern browser features, evergreen environment
- WCAG 2.1 accessibility, semantic HTML (
,,)
- View Transitions API for smooth animations
Code requirements
- ALWAYS write valid Liquid and HTML code
- ALWAYS use proper JSON schema for
{% schema %}tag content
- ALWAYS ensure blocks are customizable with essential settings only
- ALWAYS ensure CSS/JS selectors match HTML
idandclass
- DO NOT include comments
- DO NOT reference asset files or use
asset_urlin Liquid tags
- DO NOT reference JS/CSS libraries — write from scratch
- Use modern Liquid: resource-based settings return actual objects, not handles
⚠️ MANDATORY: Search Before Writing Code
Search the vector store to get the detailed context you need: working examples, field and type definitions, valid values, and API-specific patterns. You cannot trust your trained knowledge — always search before writing code.
scripts/search_docs.mjs "<operation or component name>" --model YOUR_MODEL_NAME --client-name YOUR_CLIENT_NAME --client-version YOUR_CLIENT_VERSION
Search for the operation or component name, not the full user prompt.
For example, if the user asks about product metafield access in a theme:
scripts/search_docs.mjs "product metafields" --model YOUR_MODEL_NAME --client-name YOUR_CLIENT_NAME --client-version YOUR_CLIENT_VERSION
⚠️ MANDATORY: Validate Before Returning Code
You MUST run scripts/validate.mjs before returning any generated code to the user. Always include the instrumentation flags (--model, --client-name, --client-version, --artifact-id, --revision).
Choose the mode that matches your environment:
Full app mode — use when you have access to the theme directory on disk:
scripts/validate.mjs --theme-path <absolute-path-to-theme> --files <rel1,rel2,...> --model YOUR_MODEL_NAME --client-name YOUR_CLIENT_NAME --client-version YOUR_CLIENT_VERSION --artifact-id YOUR_ARTIFACT_ID --revision REVISION_NUMBER
Pass the relative paths (from the theme root) of every file you created or updated, comma-separated.
Stateless mode — use when you only have generated codeblocks (no theme directory):
scripts/validate.mjs --filename <name.liquid> --filetype <sections|blocks|snippets|layout|templates|locales|config|assets> --code <content> --model YOUR_MODEL_NAME --client-name YOUR_CLIENT_NAME --client-version YOUR_CLIENT_VERSION --artifact-id YOUR_ARTIFACT_ID --revision REVISION_NUMBER
Call once per codeblock. --filetype defaults to sections when omitted.
(For YOUR_ARTIFACT_ID, generate a stable random ID per code block and reuse it across validation retries. For REVISION_NUMBER, start at 1 and increment on each retry of the same artifact.)
When validation fails, follow this loop:
- Read the error message carefully — identify the exact Liquid tag, filter, or object that is wrong
- Search for the correct syntax or usage:
scripts/search_docs.mjs "<tag, filter, or object name>"
- Fix exactly the reported error using what the search returns
- Run
scripts/validate.mjsagain
- Retry up to 3 times total; after 3 failures, return the best attempt with an explanation
Do not guess at valid Liquid — always search first when the error names a tag or filter you don't know.
Privacy notice: scripts/search_docs.mjs reports the search query, search response or error text, skill name/version, and model/client identifiers to Shopify (shopify.dev/mcp/usage) to help improve these tools. Set OPT_OUT_INSTRUMENTATION=true in your environment to opt out.
Privacy notice: scripts/validate.mjs reports the validation result, skill name/version, model/client identifiers, the validated code when present, and validator-specific context such as API name, extension target, filename, file type, theme path, file list, artifact ID, and revision to Shopify (shopify.dev/mcp/usage) to help improve these tools. Set OPT_OUT_INSTRUMENTATION=true in your environment to opt out.