# Integrate with Shopify > Talon.One supports integrating with Shopify using a dedicated app. > For the complete documentation index, see [llms.txt](https://docs.talon.one/llms.txt). ## Shopify integration features The Talon.One Shopify app enables real-time data synchronization between Shopify and Talon.One. By creating a bidirectional data flow, the integration enables store owners to do the following: - Sync **product data** and **customer profiles** with Talon.One, for example, to create personalized coupons or award loyalty points. - Send **customer session data**, including the customer's shopping cart. - Receive **customer data** from Talon.One, for example, the number of loyalty points awarded. - Receive **strikethrough pricing** updates from Talon.One. - Receive **discount effects** in Shopify and apply them to the shopping cart. ## Data flow ### From Shopify to Talon.One #### Product data When you [connect the app to a cart item catalog](/docs/dev/technology-partners/shopify/sync-inventory-shopify.md#connect-a-cart-item-catalog) in Talon.One, it performs an initial product sync. The app calls the [Sync cart item catalog](/integration-api#tag/Catalogs/operation/syncCatalog) endpoint to add all products in Shopify to a [cart item catalog](/docs/product/account/dev-tools/manage-cart-item-catalogs.md) in Talon.One. :::note - To re-trigger the product sync: 1. On the [Product data sync](set-up-shopify-app.md#configure-product-data-sync) page, note the value in the **Catalog ID** field. 1. Replace the value with `0`, and click **Save**. 1. Restore the previous value in the **Catalog ID** field, and click **Save**. - When synchronizing SKUs between Shopify and Talon.One, the following applies: - The `sku` field in Talon.One is populated with the variant ID from Shopify. - The SKUs in Shopify are stored in a separate `sku_shopify` field in Talon.One. This is because SKUs can be empty or duplicate in Shopify, but must be unique in Talon.One. ::: The app does not delete any data, but replaces existing products with the same variant ID. Then, whenever a product is **created**, **updated**, or **deleted** in Shopify, the app calls the same endpoint to update the cart item catalog. If any of the product data operations trigger [strikethrough pricing updates](#strikethrough-pricing-updates), Talon.One returns the effects of these updates to Shopify. #### Customer profile data When a customer profile is **created** or **updated** in Shopify, the app calls the [Update customer profile](/integration-api#tag/Customer-profiles/operation/updateCustomerProfileV2) endpoint to send customer data to Talon.One. Also, when a customer [completes their order](#customer-session-data), the profile of that customer is created or updated. The app only sends the customer data you've selected in the [customer data sync](set-up-shopify-app.md#configure-customer-data-sync) configuration. #### Customer session data When a customer adds items to their shopping cart, the app calls the [Update customer session](/integration-api#tag/Customer-sessions/operation/updateCustomerSessionV2) endpoint to create or update a [session](/docs/dev/concepts/entities/customer-sessions.md) in Talon.One. The state of the session is `open`, and the session ID is equal to the cart ID in Shopify. When a customer updates their cart, the app calls the same endpoint to update the session with the new cart data. The response from the endpoint may contain [discount effects](#discount-effects) that will be applied at checkout. When a customer completes their order, the session is updated, and its state changes to `closed`. When a return is initiated, the session state changes to `cancelled` (for fully returned orders) or `partially returned` (for partially returned orders). ### From Talon.One to Shopify #### Customer data For [theme-based](https://shopify.dev/docs/storefronts/themes) stores, an [app embed](set-up-shopify-app.md#enable-the-app-embed) is used to fetch customer data. Whenever a signed-in customer is accessing a page of your store, for example, a product page, the app embed calls the [Retrieve customer data](/shopify-integration-api#tag/Customer-profiles/operation/getCustomerThemeBased) endpoint to fetch data of that customer from Talon.One. :::note To reduce data load, the app embed fetches data only once every 10 seconds. ::: The app embed always fetches all available customer data, including customer profile, referral, coupon, loyalty, giveaway, and achievement information. For example, the data may contain a coupon generated for the customer, and their total number of awarded loyalty points. The data is stored in a customer [metafield](https://help.shopify.com/en/manual/custom-data/metafields) in Shopify. To reference it in your template, use the following [Liquid](https://shopify.dev/docs/api/liquid/) code: ```liquid {{ customer.metafields.talon_one.data }} ``` You can also access the metafield data via JavaScript: ```js const customerData = window.TalonOne.customerProfile; ``` For more information, see [our tutorial](/docs/dev/technology-partners/shopify/add-loyalty-points-shopify.md). For [headless](https://shopify.dev/docs/storefronts/headless/getting-started) stores, there's a dedicated [Retrieve customer data](/shopify-integration-api#tag/Customer-profiles/operation/getCustomerHeadless) endpoint to fetch customer data. It is recommended to call this endpoint whenever a customer signs in, or returns to the site after a period of inactivity. :::note To reduce data load, this endpoint will not fetch data more than once every 10 seconds. ::: The endpoint always fetches all available customer data, including customer profile, referral, coupon, loyalty, giveaway, and achievement information. For example, the data may contain a coupon generated for the customer, and their total number of awarded loyalty points. The data is returned as a response to your request, and is also stored in a customer [metafield](https://help.shopify.com/en/manual/custom-data/metafields) in Shopify. For more information, see [our tutorial](/docs/dev/technology-partners/shopify/add-loyalty-points-shopify.md). #### Strikethrough pricing updates Whenever the app receives a [strikethrough pricing notification](/docs/product/applications/application-notifications/overview.md#strikethrough-pricing-updates) from Talon.One, it stores the pricing effects of the notification (`changedItems.effects`, see [schema](/outbound-notifications#tag/Strikethrough-pricing-notifications/webhook/strikethroughLabelingNotification)) in a product variant [metafield](https://help.shopify.com/en/manual/custom-data/metafields) in Shopify. For example, the pricing effect can be a $10 discount on all shoes in your store. To reference the metafield in your template, use the following [Liquid](https://shopify.dev/docs/api/liquid/) code: ```liquid {{ product.selected_or_first_available_variant.metafields.talon_one.effects }} ``` For more information, see [our tutorial](/docs/dev/technology-partners/shopify/apply-strikethrough-effects-shopify.md). #### Discount effects When [customer session data](#customer-session-data) is created or updated, Talon.One may return [discount effects](/docs/dev/integration-api/api-effects.md#discounts). These effects can include discounts on the order total, individual items, or shipping costs. The app receives these effects and applies them at checkout in Shopify. For more information, see our [applying discounts tutorial](/docs/dev/technology-partners/shopify/apply-discounts-shopify.md). To install and configure the app, see [Set up the Shopify app](set-up-shopify-app.md).