How to Use Metafields to Make Your Products AI-Ready

Shopify gives you a handful of product fields out of the box: title, description, price, images, vendor, and product type. For most stores, that's where the product data ends.

But AI shopping agents need more. Material, dimensions, care instructions, target audience, compatible products — none of these exist in Shopify's default fields. If you want AI agents to truly understand your products, you need metafields.

What are metafields?

Metafields are custom data fields you can add to products, variants, collections, and other Shopify objects. They let you store structured information beyond what Shopify provides by default.

For example, a clothing store might add metafields for material, care_instructions, and fit_type. A furniture store might add dimensions, weight, and assembly_required.

Why AI agents need them

When a customer asks an AI agent "find me a machine-washable cotton throw blanket under $50," the agent needs to check materials and care instructions. If that data only lives in your description as free-form text, the agent has to guess. If it's in a structured metafield, the agent knows exactly what it's looking at.

Structured data is always easier for machines to read than unstructured text. Metafields turn your product attributes into structured data.

What metafields to add

The right metafields depend on what you sell, but these are useful for most stores:

• Material / fabric — what the product is made of
• Dimensions — length, width, height, or diameter
• Weight — especially for shipping-sensitive products
• Care instructions — washing, cleaning, maintenance
• Target audience — men, women, kids, professionals
• Use cases — indoor, outdoor, travel, work
• Compatible products — what works with this product
• Country of origin — where the product is made

How to create metafields in Shopify

1. Go to Settings > Custom data in your Shopify admin
2. Click Products (or whichever resource you want to add metafields to)
3. Click Add definition
4. Give it a name (e.g., "Material"), a namespace and key (e.g., custom.material), and choose a type (single line text, multi-line text, etc.)
5. Click Save

After you create the definition, a new field appears on every product page in your admin. Fill it in for each product.

The part most stores miss

Creating metafields and filling them in is only half the work. By default, metafield data lives inside the Shopify admin. It's not visible on your storefront, and AI agents can't see it.

For the data to be useful, your developer needs to:

1. Expose the metafields via the Storefront API — this makes the data available to headless storefronts and third-party apps
2. Render the metafields in your theme — add them to the product page template so the data appears in the HTML that AI crawlers read
3. Include them in structured data — add metafield values to the JSON-LD markup on product pages (see our structured data guide)

Without this step, you have rich product data that no AI agent can access. Data locked in admin panels helps no one.

How to verify it's working

1. Open one of your product pages in a browser
2. Right-click and select View Page Source
3. Search for the metafield value you added (e.g., the material name)
4. If you can find it in the HTML source, AI agents can see it too
5. Also check your JSON-LD structured data — search for application/ld+json in the source and look for your metafield values there

If the data doesn't appear in the page source, it's still locked in the admin. Talk to your developer about exposing it in the theme.

Quick wins

If you're not ready for custom theme development, start with these:

• Use Shopify's built-in metafield types — dimension, weight, and volume types come with unit conversion built in
• Fill in the basics first — material and care instructions give AI agents the most useful data for product matching
• Use consistent values — "100% Cotton" on every cotton product, not "cotton" on some and "Cotton fabric" on others