--- title: Add a field to checkout description: Learn how to use checkout UI extensions to add a custom field to checkout. source_url: html: https://shopify.dev/docs/apps/build/checkout/fields-banners/add-field?extension=react md: https://shopify.dev/docs/apps/build/checkout/fields-banners/add-field.md?extension=react --- # Add a field to checkout Outdated This tutorial uses an outdated API version for building Checkout UI extensions. We recommend using `2025-10` to make use of new [Polaris web components](https://shopify.dev/docs/beta/next-gen-dev-platform/polaris). A custom field is a property that allows users to enter text into a user interface. For example, you might want to create a custom field that collects delivery instructions from customers. In this tutorial, you'll use checkout UI extensions to create a custom field for collecting delivery instructions from customers, and then save those instructions to a metafield. This tutorial is for delivery instructions, but you can use it as an example to build other use cases for custom fields. Follow along with this tutorial to build a sample app, or clone the completed sample app. Before you start, consider reviewing our [custom field checkout UI extension UX guidelines](https://shopify.dev/docs/apps/build/checkout/fields-banners/ux-for-fields). Shopify Plus Checkout UI extensions are available only to [Shopify Plus](https://www.shopify.com/plus) merchants. ## What you'll learn In this tutorial, you'll learn how to do the following: * Generate a checkout UI extension that appears in the checkout flow using Shopify CLI. * Set up configurations for your checkout UI extension in the extension TOML file. * Use the Checkout UI component library to render an optional input field for customers to add a note. * Save the note to a metafield and display the value in the Shopify admin. ## Requirements * You're a [user with app development permissions](https://shopify.dev/docs/apps/build/dev-dashboard/user-permissions). * You've created a new [development store](https://shopify.dev/docs/api/development-stores) with the following: * [Generated test data](https://shopify.dev/docs/api/development-stores/generated-test-data) * [Checkout and Customer Accounts Extensibility](https://shopify.dev/docs/api/developer-previews#checkout-and-customer-accounts-extensibility-developer-preview) feature preview enabled * You've [created an app that uses Shopify CLI 3.85.1 or higher](https://shopify.dev/docs/apps/build/scaffold-app). ## Project ![](https://shopify.dev/images/logos/React.svg)![](https://shopify.dev/images/logos/React-dark.svg) React [View on GitHub](https://github.com/Shopify/example-checkout--custom-field--react) ## Create a checkout UI extension To create a checkout UI extension, you'll use Shopify CLI, which generates starter code for building your extension. To create a checkout UI extension, you can use Shopify CLI, which generates starter code for building your extension and automates common development tasks. 1. Navigate to your app directory: ## Terminal ```terminal cd ``` 2. Run the following command to create a new checkout UI extension: ## Terminal ```terminal shopify app generate extension --template checkout_ui --name my-checkout-ui-extension ``` 1) Select `Checkout UI`. You should now have a new extension directory in your app's directory. The extension directory includes the extension script at `src/Checkout.jsx`. The following is an example directory structure: ## Checkout UI extension file structure ```text └── my-app └── extensions └── my-checkout-ui-extension ├── src │ └── Checkout.jsx OR Checkout.js // The index page of the checkout UI extension ├── locales │ ├── en.default.json // The default locale for the checkout UI extension │ └── fr.json // The locale file for non-regional French translations ├── shopify.extension.toml // The config file for the checkout UI extension └── package.json ``` 1. Start your development server to build and preview your app: ## Terminal ```terminal shopify app dev ``` To learn about the processes that are executed when you run `dev`, refer to the [Shopify CLI command reference](https://shopify.dev/docs/api/shopify-cli/app/app-dev). 2. Press `p` to open the developer console. In the developer console page, click on the preview link for your extension. ### Set up an extension target Set up a target for your checkout UI extension. [Targets](https://shopify.dev/docs/api/checkout-extensions/checkout#extension-targets) control where your extension renders in the checkout flow. #### Export the extension target from your script file In your `Checkout.jsx` file, set the entrypoint for the checkout extension, and then export it so it can be referenced in your configuration. Create a `reactExtension` function that references your target, and export it using the default export. *** This extension uses the `purchase.checkout.shipping-option-list.render-after` target, so the user can provide all shipping and delivery information at the same stage in the checkout process. You can define more than one extension target so that merchants can add the extension to multiple locations in checkout. You can do this by using multiple `reactExtension` functions with different [static targets](https://shopify.dev/docs/api/checkout-ui-extensions/latest/extension-targets-overview#static-extension-targets). [react​Extension](https://shopify.dev/docs/api/checkout-ui-extensions#extension-targets)[purchase.checkout.shipping-option-list.render-after](https://shopify.dev/docs/api/checkout-ui-extensions/latest/apis/extensiontargets#typesofextensiontargets-propertydetail-purchasecheckoutshippingoptionlistrenderafter) ## /extensions/custom-field/src/Checkout.jsx ```jsx import React, { useState } from "react"; import { reactExtension, TextField, BlockStack, useApplyMetafieldsChange, useMetafield, Checkbox, } from "@shopify/ui-extensions-react/checkout"; import { useDeliveryGroupListTarget } from "@shopify/ui-extensions-react/checkout"; // Set the entry point for the extension export default reactExtension("purchase.checkout.shipping-option-list.render-after", () => ); function App() { // Set up the checkbox state const [checked, setChecked] = useState(false); // Define the metafield namespace and key const metafieldNamespace = "yourAppNamespace"; const metafieldKey = "deliveryInstructions"; // Get a reference to the metafield const deliveryInstructions = useMetafield({ namespace: metafieldNamespace, key: metafieldKey, }); // Set a function to handle updating a metafield const applyMetafieldsChange = useApplyMetafieldsChange(); // Guard against duplicate rendering of `shipping-option-list.render-after` target for one-time purchase and subscription sections. Calling `applyMetafieldsChange()` on the same namespace-key pair from duplicated extensions would otherwise cause an overwrite of the metafield value. // Instead of guarding, another approach would be to prefix the metafield key when calling `applyMetafieldsChange()`. The `deliveryGroupList`'s `groupType` could be used to such effect. const deliveryGroupList = useDeliveryGroupListTarget(); if (!deliveryGroupList || deliveryGroupList.groupType !== 'oneTimePurchase') { return null; } // Set a function to handle the Checkbox component's onChange event const handleChange = () => { setChecked(!checked); }; // Render the extension components return ( Provide delivery instructions {checked && ( { // Apply the change to the metafield applyMetafieldsChange({ type: "updateMetafield", namespace: metafieldNamespace, key: metafieldKey, valueType: "string", value, }); }} value={deliveryInstructions?.value} /> )} ); } ``` #### Reference the extension targets in your configuration file You can define more than one target so that app users can add the extension to multiple locations in the checkout. In your checkout UI extension's configuration file, for each of your targets, create an `[[extensions.targeting]]` section with the following information: * `module`: The path to the file that contains the extension code. * `target`: An identifier that specifies where you're injecting code into Shopify. *** [`shopify.extension.toml`](https://shopify.dev/docs/apps/build/app-extensions/configure-app-extensions) is the configuration file for your extension. It contains basic information and settings. Note Whenever you edit your extension configuration file, you need to restart your server for the changes to take effect. ## Terminal ```bash shopify app dev ``` ## /extensions/custom-field/shopify.extension.toml ```toml # Learn more about configuring your checkout UI extension: # https://shopify.dev/api/checkout-extensions/checkout/configuration # The version of APIs your extension will receive. Learn more: # https://shopify.dev/docs/api/usage/versioning api_version = "2024-07" [[extensions]] name = "custom-field" type = "ui_extension" handle = "custom-field" [[extensions.targeting]] module = "./src/Checkout.jsx" target = "purchase.checkout.shipping-option-list.render-after" ``` ## Set up a metafield Now that you've set up the extension target, you'll save custom field values in a metafield. Regular metafields are available to any app or extension. Info If you need to capture multiple dynamic fields, then consider using [checkout attributes](https://shopify.dev/docs/api/checkout-ui-extensions/unstable/apis/attributes#checkoutapi-propertydetail-applyattributechange) where you can define a namespace and key programatically without having to pre-define them in your `shopify.extension.toml`. For example, you might need to collect input for [both one-time purchase and subscription delivery group lists](https://shopify.dev/docs/api/checkout-ui-extensions/unstable/targets/shipping/purchase-checkout-shipping-option-list-render-before). ### Define the metafield namespace and key Set a namespace and key for the metafield where you want to store the custom field value. Later, you'll expose values stored in this metafield to merchants in the Shopify admin. *** A [metafield](https://shopify.dev/docs/apps/build/custom-data/metafields/manage-metafields) is a custom field that you can use to store additional information about a Shopify resource. You can use metafields to store information specific to your app without setting up your own storage. ## /extensions/custom-field/src/Checkout.jsx ```jsx import React, { useState } from "react"; import { reactExtension, TextField, BlockStack, useApplyMetafieldsChange, useMetafield, Checkbox, } from "@shopify/ui-extensions-react/checkout"; import { useDeliveryGroupListTarget } from "@shopify/ui-extensions-react/checkout"; // Set the entry point for the extension export default reactExtension("purchase.checkout.shipping-option-list.render-after", () => ); function App() { // Set up the checkbox state const [checked, setChecked] = useState(false); // Define the metafield namespace and key const metafieldNamespace = "yourAppNamespace"; const metafieldKey = "deliveryInstructions"; // Get a reference to the metafield const deliveryInstructions = useMetafield({ namespace: metafieldNamespace, key: metafieldKey, }); // Set a function to handle updating a metafield const applyMetafieldsChange = useApplyMetafieldsChange(); // Guard against duplicate rendering of `shipping-option-list.render-after` target for one-time purchase and subscription sections. Calling `applyMetafieldsChange()` on the same namespace-key pair from duplicated extensions would otherwise cause an overwrite of the metafield value. // Instead of guarding, another approach would be to prefix the metafield key when calling `applyMetafieldsChange()`. The `deliveryGroupList`'s `groupType` could be used to such effect. const deliveryGroupList = useDeliveryGroupListTarget(); if (!deliveryGroupList || deliveryGroupList.groupType !== 'oneTimePurchase') { return null; } // Set a function to handle the Checkbox component's onChange event const handleChange = () => { setChecked(!checked); }; // Render the extension components return ( Provide delivery instructions {checked && ( { // Apply the change to the metafield applyMetafieldsChange({ type: "updateMetafield", namespace: metafieldNamespace, key: metafieldKey, valueType: "string", value, }); }} value={deliveryInstructions?.value} /> )} ); } ``` ## Add a delivery instruction input Build a basic user interface using components from the [checkout UI extensions](https://shopify.dev/docs/api/checkout-ui-extensions/latest/components) component library. ### Add a delivery instruction option and text field Using checkout UI components, build a basic UI for the delivery instruction input. *** This UI includes a checkbox to specify whether the customer wants to add a delivery instruction. When the checkbox is checked, a text field appears for the customer to enter the delivery instruction. If the customer has already entered a value, then the value is displayed. Checkout UI extensions are limited to specific UI components exposed by the platform [for security reasons](https://shopify.dev/docs/api/checkout-ui-extensions#security). Checkout UI components allow you to create a UI that feels seamless within the checkout experience, and that inherits a merchant's brand settings. [Block​Stack](https://shopify.dev/docs/api/checkout-ui-extensions/latest/components/structure/blockstack)[Checkbox](https://shopify.dev/docs/api/checkout-ui-extensions/latest/components/forms/checkbox)[Text​Field](https://shopify.dev/docs/api/checkout-ui-extensions/latest/components/forms/textfield) ## /extensions/custom-field/src/Checkout.jsx ```jsx import React, { useState } from "react"; import { reactExtension, TextField, BlockStack, useApplyMetafieldsChange, useMetafield, Checkbox, } from "@shopify/ui-extensions-react/checkout"; import { useDeliveryGroupListTarget } from "@shopify/ui-extensions-react/checkout"; // Set the entry point for the extension export default reactExtension("purchase.checkout.shipping-option-list.render-after", () => ); function App() { // Set up the checkbox state const [checked, setChecked] = useState(false); // Define the metafield namespace and key const metafieldNamespace = "yourAppNamespace"; const metafieldKey = "deliveryInstructions"; // Get a reference to the metafield const deliveryInstructions = useMetafield({ namespace: metafieldNamespace, key: metafieldKey, }); // Set a function to handle updating a metafield const applyMetafieldsChange = useApplyMetafieldsChange(); // Guard against duplicate rendering of `shipping-option-list.render-after` target for one-time purchase and subscription sections. Calling `applyMetafieldsChange()` on the same namespace-key pair from duplicated extensions would otherwise cause an overwrite of the metafield value. // Instead of guarding, another approach would be to prefix the metafield key when calling `applyMetafieldsChange()`. The `deliveryGroupList`'s `groupType` could be used to such effect. const deliveryGroupList = useDeliveryGroupListTarget(); if (!deliveryGroupList || deliveryGroupList.groupType !== 'oneTimePurchase') { return null; } // Set a function to handle the Checkbox component's onChange event const handleChange = () => { setChecked(!checked); }; // Render the extension components return ( Provide delivery instructions {checked && ( { // Apply the change to the metafield applyMetafieldsChange({ type: "updateMetafield", namespace: metafieldNamespace, key: metafieldKey, valueType: "string", value, }); }} value={deliveryInstructions?.value} /> )} ); } ``` ### Store the user input in the metafield Use the `useApplyMetafieldsChange` hook to store the value that the customer enters in the `metafields` property of the checkout. This metafield value is later associated with the order. *** `useApplyMetafieldsChange` is a React hook that lets you write metafield values. To learn more about the hooks available for checkout UI extensions, refer to the [Checkout UI extension reference](https://shopify.dev/docs/api/checkout-ui-extensions/latest/react-hooks). [use​Apply​Metafields​Change](https://shopify.dev/docs/api/checkout-ui-extensions/latest/react-hooks/cart/useapplymetafieldschange) ## /extensions/custom-field/src/Checkout.jsx ```jsx import React, { useState } from "react"; import { reactExtension, TextField, BlockStack, useApplyMetafieldsChange, useMetafield, Checkbox, } from "@shopify/ui-extensions-react/checkout"; import { useDeliveryGroupListTarget } from "@shopify/ui-extensions-react/checkout"; // Set the entry point for the extension export default reactExtension("purchase.checkout.shipping-option-list.render-after", () => ); function App() { // Set up the checkbox state const [checked, setChecked] = useState(false); // Define the metafield namespace and key const metafieldNamespace = "yourAppNamespace"; const metafieldKey = "deliveryInstructions"; // Get a reference to the metafield const deliveryInstructions = useMetafield({ namespace: metafieldNamespace, key: metafieldKey, }); // Set a function to handle updating a metafield const applyMetafieldsChange = useApplyMetafieldsChange(); // Guard against duplicate rendering of `shipping-option-list.render-after` target for one-time purchase and subscription sections. Calling `applyMetafieldsChange()` on the same namespace-key pair from duplicated extensions would otherwise cause an overwrite of the metafield value. // Instead of guarding, another approach would be to prefix the metafield key when calling `applyMetafieldsChange()`. The `deliveryGroupList`'s `groupType` could be used to such effect. const deliveryGroupList = useDeliveryGroupListTarget(); if (!deliveryGroupList || deliveryGroupList.groupType !== 'oneTimePurchase') { return null; } // Set a function to handle the Checkbox component's onChange event const handleChange = () => { setChecked(!checked); }; // Render the extension components return ( Provide delivery instructions {checked && ( { // Apply the change to the metafield applyMetafieldsChange({ type: "updateMetafield", namespace: metafieldNamespace, key: metafieldKey, valueType: "string", value, }); }} value={deliveryInstructions?.value} /> )} ); } ``` ## Show the note in the Shopify admin After you've saved the note metafield to the order, display it on the order details page in the Shopify admin so that users can view it. ### Add a metafield definition in the Shopify admin In the Shopify admin, add an **Order** [metafield definition](https://help.shopify.com/manual/custom-data/metafields/metafield-definitions/creating-custom-metafield-definitions) for your delivery instruction metafield. The type should be **Single line text**. Use the same `namespace` and `key` that you defined [in your `Checkout.jsx` file](#set-up-a-metafield). Tip If you already placed an order with delivery instructions, then you might need to select the metafield from the [**Metafields without a definition** list](https://help.shopify.com/manual/custom-data/metafields/metafield-definitions/migrating-metafields-to-a-definition#definitions-for-existing-metafields). ### Preview the extension Preview your extension to make sure that it works as expected. #### Start your server Run the Shopify CLI `dev` command to build your app and preview it on your development store. Make sure that you select a development store that has enabled the feature preview for [Checkout and Customer Accounts Extensibility](https://shopify.dev/docs/api/developer-previews#checkout-and-customer-accounts-extensibility-developer-preview). 1. In a terminal, navigate to your app directory. 2. Either start or restart your server to build and preview your app: ## Terminal ```bash shopify app dev ``` 3. Press `p` to open the developer console. 4. In the developer console page, click on the preview link for the custom field extension. The checkout opens. Note Your Provide delivery instructions checkbox should render in the Shipping step of the checkout. *** This section describes how to solve some potential errors when you run `dev` for an app that contains a checkout UI extension. ### Property token error If you receive the error `ShopifyCLI:AdminAPI requires the property token to be set`, then you'll need to use the [`--checkout-cart-url` flag](https://shopify.dev/docs/api/shopify-cli/app/app-dev#flags) to direct Shopify CLI to open a checkout session for you. ## Terminal ```terminal shopify app dev --checkout-cart-url cart/{product_variant_id}:{quantity} ``` ### Missing checkout link If you don't receive the test checkout URL when you run `dev`, then verify the following: * You have a development store populated with products. * You're logged in to the correct Partners organization and development store. To verify, check your app info using the following command: ## Terminal ```terminal shopify app info ``` Otherwise, you can manually create a checkout with the following steps: 1. From your development store's storefront, add some products to your cart. 2. From the cart, click **Checkout**. 3. From directory of the app that contains your extension, run `dev` to preview your app: ## Terminal ```terminal shopify app dev ``` 4. On the checkout page for your store, change the URL by appending the `?dev=https://{tunnel_url}/extensions` query string and reload the page. The `tunnel_url` parameter allows your app to be accessed using a unique HTTPS URL. You should now see a rendered order note that corresponds to the code in your project template. ## Test the extension Test your extension to make sure that it works as expected. ### Test the extension in checkout Place an order with delivery instructions in the checkout. 1. With your server running, open the storefront of your development store. 2. Add a product to the cart and then check out. 3. Fill out the contact and shipping address information, and then move to the **Shipping** step of the checkout. Your **Provide delivery instructions** checkbox appears. 4. Select the **Provide delivery instructions** checkbox. A text field appears. 5. Enter a value in the text field and then complete the checkout. 6. In the Shopify admin for the development store, open the order details page for the order that you just placed. The delivery instructions that you entered are displayed in the **Metafields** section, in the delivery instructions field that you created. *** ![Delivery instructions in the order details page.](https://cdn.shopify.com/shopifycloud/shopify-dev/production/assets/assets/apps/checkout/metafield-By9MqDB4.png) When you're ready to release your changes to users, you can create and release an [app version](https://shopify.dev/docs/apps/launch/deployment/app-versions). An app version is a snapshot of your app configuration and all extensions. 1. Navigate to your app directory. 2. Run the following command. Optionally, you can provide a name or message for the version using the `--version` and `--message` flags. ## Terminal ```terminal shopify app deploy ``` Releasing an app version replaces the current active version that's served to stores that have your app installed. It might take several minutes for app users to be upgraded to the new version. Tip If you want to create a version, but avoid releasing it to users, then run the `deploy` command with a `--no-release` flag. You can release the unreleased app version using Shopify CLI's [`release`](https://shopify.dev/docs/api/shopify-cli/app/app-release) command, or through the Dev Dashboard. ## /extensions/custom-field/shopify.extension.toml ```toml # Learn more about configuring your checkout UI extension: # https://shopify.dev/api/checkout-extensions/checkout/configuration # The version of APIs your extension will receive. Learn more: # https://shopify.dev/docs/api/usage/versioning api_version = "2024-07" [[extensions]] name = "custom-field" type = "ui_extension" handle = "custom-field" [[extensions.targeting]] module = "./src/Checkout.jsx" target = "purchase.checkout.shipping-option-list.render-after" ``` ## Tutorial complete! Nice work - what you just built could be used by Shopify merchants around the world! Keep the momentum going with these related tutorials and resources. ### Next steps [![](https://shopify.dev/images/icons/32/build.png)![](https://shopify.dev/images/icons/32/build-dark.png)](https://shopify.dev/docs/apps/checkout/custom/fields/ux-guidelines) [Review custom field UX guidelines](https://shopify.dev/docs/apps/checkout/custom/fields/ux-guidelines) [Build a user experience by following our UX guidelines.](https://shopify.dev/docs/apps/checkout/custom/fields/ux-guidelines) [![](https://shopify.dev/images/icons/32/globe.png)![](https://shopify.dev/images/icons/32/globe-dark.png)](https://shopify.dev/docs/apps/checkout/localizing-ui-extensions) [Localize your extension](https://shopify.dev/docs/apps/checkout/localizing-ui-extensions) [Learn how to localize the text and number formats in your extension.](https://shopify.dev/docs/apps/checkout/localizing-ui-extensions) [![](https://shopify.dev/images/icons/32/blocks.png)![](https://shopify.dev/images/icons/32/blocks-dark.png)](https://shopify.dev/docs/api/checkout-ui-extensions/latest/components) [Explore the checkout UI extension component reference](https://shopify.dev/docs/api/checkout-ui-extensions/latest/components) [Learn about all of the components that you can use in your checkout UI extension.](https://shopify.dev/docs/api/checkout-ui-extensions/latest/components) [![](https://shopify.dev/images/icons/32/build.png)![](https://shopify.dev/images/icons/32/build-dark.png)](https://shopify.dev/docs/api/checkout-ui-extensions/latest/apis/extensiontargets) [Explore the checkout UI extension targets API reference](https://shopify.dev/docs/api/checkout-ui-extensions/latest/apis/extensiontargets) [Learn about the extension targets offered in checkout.](https://shopify.dev/docs/api/checkout-ui-extensions/latest/apis/extensiontargets)