> For the complete documentation index, see [llms.txt](https://docs.selvette.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.selvette.com/custom-sites/product-references.md).

# Set product references and images

Two dynamic attributes identify the product currently being viewed.

## Product reference

Set `data-tryon-product` to a stable value that does not change between visits.

For custom sites, use a reference such as:

```html
data-tryon-product="custom:silk-slip-dress"
```

The custom portion can contain letters, numbers, periods, underscores, and hyphens. Keep the value at 64 characters or fewer.

Selvette uses this reference for:

* product availability;
* Insights and CSV rows; and
* the custom add-to-cart hook.

## Product image

Set `data-tryon-product-image` to the full HTTPS URL of the product image used for try-on.

```html
data-tryon-product-image="https://your-site.com/images/silk-slip-dress.jpg"
```

Use PNG, JPEG, or WebP. The value must be a real product URL—not the example left in the copied snippet.

## Optional attributes

| Attribute             | Use                                                               |
| --------------------- | ----------------------------------------------------------------- |
| `data-variant`        | A fallback variant reference for add to cart                      |
| `data-collections`    | Comma-separated collection references for collection availability |
| `data-customer-email` | Prefills the result email field for a signed-in shopper           |
| `data-sample`         | Shows your own sample result before upload                        |

Next: [Allow your storefront origin](/custom-sites/allowed-origins.md)


---

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```
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