Install and configure Radiant

Radiant is installed from Shopify and configured inside the embedded app. A complete setup connects four things: a published size chart, a catalog assignment, storefront defaults, and at least one theme placement.

Before you begin#

Use the store owner account, or a staff member or collaborator with permission to manage apps and themes. Keep one published product available for testing, and make sure that product has the sizes and variants shoppers can actually buy.

You do not need to expose the whole catalog while configuring Radiant. One representative product is enough to validate the first path end to end.

Complete the setup milestones#

1. Create a size chart#

Open Size charts, then choose From template or Create from scratch. Use the measurement labels and size names that appear on the product. A recommendation can only be as useful as the chart behind it.

Review the content before publishing:

• size labels match the product variants;
• units and ranges are internally consistent;
• measurement guidance describes how the garment or body value should be read;
• Smart Selector is used only when the chart contains supported measurement columns.

Continue with Create and publish a size chart.

2. Assign the chart#

Open Assignments and connect the chart to a product or catalog rule. Product rules are the most specific. Collection, product type, vendor, tag, and entire site rules can cover broader groups.

An assignment does not change the chart itself. It decides which published chart an eligible product receives. See Assignments and rule priority.

3. Configure the storefront experience#

Open Settings and Customization to choose the language behavior, launcher, panel presentation, colors, typography, branding, and Smart Selector experience. Save functional settings and visual changes before testing.

The language setting can follow the active Shopify storefront language automatically. English, Spanish, and Portuguese (Brazil) can also be selected directly. Merchant-written chart content is not automatically translated.

4. Add Radiant to the theme#

Radiant offers two theme locations:

1. App embed — provides a floating launcher on eligible product pages.
2. Product page block — adds an inline Size selector block that can be positioned in the product template.

You can use either location or both. Open the Theme Editor from the setup action, enable or add the chosen location, and save the theme. Full instructions are in Storefront setup.

Verify the first product#

Open a published product that matches the assignment and check the following:

1. the expected launcher or block is visible;
2. the chart title, sizes, units, and instructions are correct;
3. the full size table opens;
4. Smart Selector opens only when the chart is eligible;
5. the experience is usable on desktop and mobile;
6. the theme placement does not cover product controls or important content.

If the chart is visible in the app preview but not on the storefront, verify the assignment, chart status, theme save state, and product eligibility separately. The preview confirms appearance; it does not prove that a storefront product matches the assignment.

A safe launch sequence#

Start with a narrow assignment, verify it, and then expand coverage. This makes it easier to identify whether a problem belongs to the chart, rule, theme, or product.

When the first product is correct:

• test another product covered by the same rule;
• test a product that should not receive the chart;
• confirm the mobile layout;
• check both centimeters and inches when the unit switch is enabled;
• repeat after changing the Shopify theme or product template.

Next steps#

• Create and publish a size chart
• Assign charts to the catalog
• Place Radiant in the storefront
• Customize the widget

If the setup still does not behave as expected, use the troubleshooting guide or contact support.