App extensions and functions

Some apps add features to your store using extensions and functions. Extensions and functions are set up by the app developer and become available when you install and activate the app.

Extensions allow apps to add functionality to areas such as your Online Store, checkout, customer accounts, or Point of Sale. For example, an app might add a custom field to your checkout page, open a chat bot on your online store, or display loyalty points in customer accounts.

Functions allow apps to customize your store's backend logic. For example, an app might use a function to create a custom discount type, adjust delivery options at checkout, or apply specific payment rules. Functions run automatically as part of your store's operations after you set up the app.

You can view and manage extensions and functions for your installed apps from Settings > Apps in your Shopify admin. On the app's about page, the Extensions and Functions cards display how many are currently active and the areas of your store where they're available. Hover over the areas text to view where they're active, such as Checkout, Customer accounts, Online Store, or POS for extensions, and Checkout, Discounts, Payments, or Shipping and delivery for functions.

Click Extensions or Functions to view the full list for that app. On the Extensions or Functions page, you can switch between the Active and Inactive tabs to review which extensions or functions are currently running. Click an extension or function name to navigate to the area of your store where it can be activated or managed.

If you're an app developer, then refer to the Shopify dev docs on extensions and Shopify dev docs on functions for technical documentation.

Activating extensions and functions

You activate and deactivate extensions and functions in the area of your Shopify admin where they're used. From the Extensions or Functions page in the app's settings, click an extension or function name to navigate to the area where it can be managed. After you activate an extension or function, it displays as active on the app's about page.

Extensions

Extensions can be activated in the following areas of your Shopify admin:

• Online Store: Add app blocks and app embeds through the theme editor. Learn how to customize your theme with apps.
• Checkout: Add app extensions in the checkout editor. Learn how to manage checkout apps. To remove an extension, refer to remove an app.
• Customer accounts: Add app extensions in the checkout editor. Learn how to manage checkout apps for customer accounts.
• POS: Add extensions to your Point of Sale. Learn how to manage POS UI extensions.

Functions

Functions can be activated in the following areas of your Shopify admin:

• Checkout: Add cart and checkout validation rules. Learn how to add cart and checkout validation. To deactivate or remove a rule, refer to deactivate a checkout rule or remove a checkout rule.
• Discounts: Create custom discount types with an app. Learn how to create your own discount with an app.
• Shipping and delivery: Add delivery customizations. Learn how to add a delivery customization.
• Payments: Add payment method customizations. Learn how to add a payment method customization.

Troubleshooting function errors

If a function encounters an error, then a warning is displayed on the Functions card on the app's about page and on the functions page. The card displays Errors on [number] area instead of the usual available areas count, and the warning indicates when the most recent errors were detected.

On the Functions page, functions that have errors are highlighted with a icon. If a function has errors, then contact the app developer for help. In some cases, the error might already be resolved. You can also share function logs to help the developer troubleshoot the issue.