Atlas adds three things to your Shopify theme. Each powers one feature, and each has to be switched on for the theme customers actually see. If an Atlas feature has stopped working, the answer is almost always one of these three being off.
In this article:
The three extensions
Extension | Type | Theme editor name | Required for |
Atlas Page Builder | App embed |
| Every page Atlas publishes |
Atlas Cart Upsells | App embed |
| The cart drawer |
Atlas Bundler | App block |
| Bundle offers on product pages |
Embeds and blocks are different
This distinction explains why one of them behaves unlike the other two.
App embeds are switched on once per theme, in Theme settings, then App embeds. They apply across the whole theme. Their status reads Active or Inactive, and the action is Activate.
App blocks are placed on a specific template, in a specific position, like any other section. The Atlas Bundler is a block, which is why its status reads Added or Not added and its action is Add to theme.
⚠️ Because the Bundler is a block, it only works on the template it was added to. If your products use more than one product template, the block must be added to each one. This is the most common reason bundles show on some products and not others.
What each one powers
Atlas Page Builder, tooltip Required for pages published by Atlas.
Without it: pages Atlas published do not render correctly, and publishing new pages is blocked with Enable Atlas in your theme to publish. This is the one that affects the most, because every product page, full store page, landing page and page variation depends on it.
Atlas Cart Upsells, tooltip Shows your upsell offers in the cart.
Without it: your theme's own cart drawer is used instead, and every module you configured disappears at once. No error appears anywhere on the storefront.
Atlas Bundler, tooltip Shows your bundle offers on product pages.
Without it: bundle offers are invisible. The discounts still exist. Any discounts you have set up are already active on your store. The offer is missing, not the discount.
Where to check them
The Theme extensions card on your Atlas dashboard shows all three at once, for your published theme, which it names in the subtitle.
Each one that is not active carries a button that takes you straight to the right place in the theme editor.
If Atlas cannot read your theme you will see Couldn't check your theme extensions. Re-check in a moment. with a Re-check button.
Per theme, not per store
All three are configured per theme. This matters more than anything else on this page.
Situation | What happens | What to do |
You publish a new theme | All three are off on it unless enabled | Enable them before publishing the theme |
You duplicate a theme | The copy usually keeps them, but confirm | Check before publishing the copy |
You restore a theme backup | The backup predates your settings | Re-enable and re-add |
Your theme developer pushes an update | Settings can be replaced | Re-check afterwards |
⚠️ Publishing a theme without these enabled breaks every Atlas feature on your storefront at once, silently. There is no error and no warning. Enable them on the new theme while it is still unpublished, then publish.
How discounts are applied
Separately from the three extensions above, Atlas installs two Shopify Functions that apply discounts at checkout: one for bundle offers and one for cart drawer offers.
You do not configure these and they do not appear in your theme editor. They matter for one reason: they run through the Shopify cart and checkout. Any checkout flow that bypasses the Shopify cart never invokes them, which is why third-party checkout and cash on delivery apps do not receive Atlas discounts.