What is a theme app extension?

In more detail

Before theme app extensions, apps changed a store by inserting code into theme files. That code often stayed behind after the app was uninstalled, and theme updates could overwrite or break it. A theme app extension keeps the app’s code in the app, versioned and deployed by the developer, and leaves the theme’s own files untouched.

There are two kinds of block. App blocks sit inside sections, where you place and arrange them in the theme editor, and need a theme built on Online Store 2.0 JSON templates. App embed blocks load across the storefront, for things such as a pixel or a floating element, and you switch them on or off under App embeds in the theme editor.

A block’s settings live in the theme editor or in metafields the app owns, so an app can change what a block shows without touching the theme. You stay in control of whether a block appears at all.

Key points

• The app never edits theme files; you place or switch on its blocks.
• App blocks need an Online Store 2.0 theme; app embed blocks are switched on under App embeds.
• Removing the app removes its blocks, with no code left behind.
• Required by Shopify’s App Store requirement 5.1.1 for any app that modifies a theme.

How Liftable relates

Sources

1. Shopify App Store requirements, 5.1.1. “If your app modifies the merchant’s theme, you need to use theme app extensions.”
2. Shopify docs: About theme app extensions. Describes app blocks and app embed blocks, and how they are added to a theme without editing theme code.