diff --git a/plugins/woocommerce-blocks/src/RestApi.php b/plugins/woocommerce-blocks/src/RestApi.php
index 885b918ee18..959bc34f446 100644
--- a/plugins/woocommerce-blocks/src/RestApi.php
+++ b/plugins/woocommerce-blocks/src/RestApi.php
@@ -94,6 +94,7 @@ class RestApi {
 			'product-reviews'               => __NAMESPACE__ . '\RestApi\Controllers\ProductReviews',
 			'store-cart'                    => __NAMESPACE__ . '\RestApi\StoreApi\Controllers\Cart',
 			'store-cart-items'              => __NAMESPACE__ . '\RestApi\StoreApi\Controllers\CartItems',
+			'store-cart-coupons'            => __NAMESPACE__ . '\RestApi\StoreApi\Controllers\CartCoupons',
 			'store-products'                => __NAMESPACE__ . '\RestApi\StoreApi\Controllers\Products',
 			'store-product-collection-data' => __NAMESPACE__ . '\RestApi\StoreApi\Controllers\ProductCollectionData',
 			'store-product-attributes'      => __NAMESPACE__ . '\RestApi\StoreApi\Controllers\ProductAttributes',
diff --git a/plugins/woocommerce-blocks/src/RestApi/StoreApi/Controllers/CartCoupons.php b/plugins/woocommerce-blocks/src/RestApi/StoreApi/Controllers/CartCoupons.php
new file mode 100644
index 00000000000..37542c4e2c4
--- /dev/null
+++ b/plugins/woocommerce-blocks/src/RestApi/StoreApi/Controllers/CartCoupons.php
@@ -0,0 +1,252 @@
+<?php
+/**
+ * Cart Coupons controller.
+ *
+ * @internal This API is used internally by Blocks--it is still in flux and may be subject to revisions.
+ * @package WooCommerce/Blocks
+ */
+
+namespace Automattic\WooCommerce\Blocks\RestApi\StoreApi\Controllers;
+
+defined( 'ABSPATH' ) || exit;
+
+use \WP_Error as RestError;
+use \WP_REST_Server as RestServer;
+use \WP_REST_Controller as RestController;
+use \WP_REST_Response as RestResponse;
+use \WP_REST_Request as RestRequest;
+use \WC_REST_Exception as RestException;
+use Automattic\WooCommerce\Blocks\RestApi\StoreApi\Schemas\CartCouponSchema;
+use Automattic\WooCommerce\Blocks\RestApi\StoreApi\Utilities\CartController;
+
+/**
+ * Cart Coupons API.
+ */
+class CartCoupons extends RestController {
+	/**
+	 * Endpoint namespace.
+	 *
+	 * @var string
+	 */
+	protected $namespace = 'wc/store';
+
+	/**
+	 * Route base.
+	 *
+	 * @var string
+	 */
+	protected $rest_base = 'cart/coupons';
+
+	/**
+	 * Schema class instance.
+	 *
+	 * @var object
+	 */
+	protected $schema;
+
+	/**
+	 * Setup API class.
+	 */
+	public function __construct() {
+		$this->schema = new CartCouponSchema();
+	}
+
+	/**
+	 * Register routes.
+	 */
+	public function register_routes() {
+		register_rest_route(
+			$this->namespace,
+			'/' . $this->rest_base,
+			[
+				[
+					'methods'  => RestServer::READABLE,
+					'callback' => [ $this, 'get_items' ],
+					'args'     => [
+						'context' => $this->get_context_param( [ 'default' => 'view' ] ),
+					],
+				],
+				[
+					'methods'  => RestServer::CREATABLE,
+					'callback' => array( $this, 'create_item' ),
+					'args'     => $this->get_endpoint_args_for_item_schema( RestServer::CREATABLE ),
+				],
+				[
+					'methods'  => RestServer::DELETABLE,
+					'callback' => [ $this, 'delete_items' ],
+				],
+				'schema' => [ $this, 'get_public_item_schema' ],
+			]
+		);
+		register_rest_route(
+			$this->namespace,
+			'/' . $this->rest_base . '/(?P<code>[\w-]+)',
+			[
+				'args'   => [
+					'code' => [
+						'description' => __( 'Unique identifier for the coupon within the cart.', 'woo-gutenberg-products-block' ),
+						'type'        => 'string',
+					],
+				],
+				[
+					'methods'  => RestServer::READABLE,
+					'callback' => [ $this, 'get_item' ],
+					'args'     => [
+						'context' => $this->get_context_param( [ 'default' => 'view' ] ),
+					],
+				],
+				[
+					'methods'  => RestServer::DELETABLE,
+					'callback' => [ $this, 'delete_item' ],
+				],
+				'schema' => [ $this, 'get_public_item_schema' ],
+			]
+		);
+	}
+
+	/**
+	 * Get a collection of cart coupons.
+	 *
+	 * @param RestRequest $request Full details about the request.
+	 * @return RestError|RestResponse
+	 */
+	public function get_items( $request ) {
+		$controller   = new CartController();
+		$cart_coupons = $controller->get_cart_coupons();
+		$items        = [];
+
+		foreach ( $cart_coupons as $coupon_code ) {
+			$response = $this->prepare_item_for_response( $coupon_code, $request );
+			$response->add_links( $this->prepare_links( $coupon_code ) );
+
+			$response = $this->prepare_response_for_collection( $response );
+			$items[]  = $response;
+		}
+
+		$response = rest_ensure_response( $items );
+
+		return $response;
+	}
+
+	/**
+	 * Get a single cart coupon.
+	 *
+	 * @param RestRequest $request Full details about the request.
+	 * @return RestError|RestResponse
+	 */
+	public function get_item( $request ) {
+		$controller = new CartController();
+
+		if ( ! $controller->has_coupon( $request['code'] ) ) {
+			return new RestError( 'woocommerce_rest_cart_coupon_invalid_code', __( 'Coupon does not exist in the cart.', 'woo-gutenberg-products-block' ), array( 'status' => 404 ) );
+		}
+
+		$data     = $this->prepare_item_for_response( $request['code'], $request );
+		$response = rest_ensure_response( $data );
+
+		return $response;
+	}
+
+	/**
+	 * Add a coupon to the cart and return the result.
+	 *
+	 * @param RestRequest $request Full data about the request.
+	 * @return RestError|RestResponse Response object on success, or WP_Error object on failure.
+	 */
+	public function create_item( $request ) {
+		if ( ! wc_coupons_enabled() ) {
+			return new RestError( 'woocommerce_rest_cart_coupon_disabled', __( 'Coupons are disabled.', 'woo-gutenberg-products-block' ), array( 'status' => 404 ) );
+		}
+
+		$controller = new CartController();
+
+		try {
+			$controller->apply_coupon( $request['code'] );
+		} catch ( RestException $e ) {
+			return new RestError( $e->getErrorCode(), $e->getMessage(), array( 'status' => $e->getCode() ) );
+		}
+
+		$response = $this->get_item( $request );
+
+		if ( $response instanceof RestError ) {
+			return $response;
+		}
+
+		$response = rest_ensure_response( $response );
+		$response->set_status( 201 );
+
+		return $response;
+	}
+
+	/**
+	 * Delete a single cart coupon.
+	 *
+	 * @param RestRequest $request Full data about the request.
+	 * @return RestError|RestResponse Response object on success, or WP_Error object on failure.
+	 */
+	public function delete_item( $request ) {
+		$controller = new CartController();
+
+		if ( ! $controller->has_coupon( $request['code'] ) ) {
+			return new RestError( 'woocommerce_rest_cart_coupon_invalid_code', __( 'Coupon does not exist in the cart.', 'woo-gutenberg-products-block' ), array( 'status' => 404 ) );
+		}
+
+		$cart = $controller->get_cart_instance();
+		$cart->remove_coupon( $request['code'] );
+
+		return new RestResponse( null, 204 );
+	}
+
+	/**
+	 * Deletes all coupons in the cart.
+	 *
+	 * @param RestRequest $request Full data about the request.
+	 * @return RestError|RestResponse Response object on success, or WP_Error object on failure.
+	 */
+	public function delete_items( $request ) {
+		$controller = new CartController();
+		$cart       = $controller->get_cart_instance();
+		$cart->remove_coupons();
+
+		return new RestResponse( [], 200 );
+	}
+
+	/**
+	 * Cart item schema.
+	 *
+	 * @return array
+	 */
+	public function get_item_schema() {
+		return $this->schema->get_item_schema();
+	}
+
+	/**
+	 * Prepares a single item output for response.
+	 *
+	 * @param string      $coupon_code Coupon code.
+	 * @param RestRequest $request Request object.
+	 * @return RestResponse Response object.
+	 */
+	public function prepare_item_for_response( $coupon_code, $request ) {
+		return rest_ensure_response( $this->schema->get_item_response( $coupon_code ) );
+	}
+
+	/**
+	 * Prepare links for the request.
+	 *
+	 * @param string $coupon_code Coupon code.
+	 * @return array
+	 */
+	protected function prepare_links( $coupon_code ) {
+		$base  = $this->namespace . '/' . $this->rest_base;
+		$links = array(
+			'self'       => array(
+				'href' => rest_url( trailingslashit( $base ) . $coupon_code ),
+			),
+			'collection' => array(
+				'href' => rest_url( $base ),
+			),
+		);
+		return $links;
+	}
+}
diff --git a/plugins/woocommerce-blocks/src/RestApi/StoreApi/README.md b/plugins/woocommerce-blocks/src/RestApi/StoreApi/README.md
index 60519ce164b..0d472d5ca13 100644
--- a/plugins/woocommerce-blocks/src/RestApi/StoreApi/README.md
+++ b/plugins/woocommerce-blocks/src/RestApi/StoreApi/README.md
@@ -90,6 +90,7 @@ Available resources in the Store API include:
 | [`Products`](#products-api)                                | `/wc/store/products`                    |
 | [`Cart`](#cart-api)                                        | `/wc/store/cart`                        |
 | [`Cart Items`](#cart-items-api)                            | `/wc/store/cart/items`                  |
+| [`Cart Coupons`](#cart-coupons-api)                        | `/wc/store/cart/coupons`                |
 | [`Cart Shipping Rates`](#cart-shipping-rates-api)          | `/wc/store/cart/shipping-rates`         |
 | [`Product Attributes`](#product-attributes-api)            | `/wc/store/products/attributes`         |
 | [`Product Attribute Terms`](#product-attribute-terms-api)  | `/wc/store/products/attributes/1/terms` |
@@ -321,6 +322,7 @@ Example response:
 
 ```json
 {
+	"coupons": [],
 	"items": [
 		{
 			"key": "6512bd43d9caa6e02c990b0a82652dca",
@@ -800,6 +802,159 @@ Example response:
 []
 ```
 
+## Cart coupons API
+
+### List cart coupons
+
+```http
+GET /cart/coupons
+```
+
+There are no parameters required for this endpoint.
+
+```http
+curl "https://example-store.com/wp-json/wc/store/cart/items"
+```
+
+Example response:
+
+```json
+[
+  {
+    "code": "20off",
+    "totals": {
+      "currency_code": "GBP",
+      "currency_symbol": "£",
+      "currency_minor_unit": 2,
+      "currency_decimal_separator": ".",
+      "currency_thousand_separator": ",",
+      "currency_prefix": "£",
+      "currency_suffix": "",
+      "total_discount": "1667",
+      "total_discount_tax": "333"
+    },
+    "_links": {
+      "self": [
+        {
+          "href": "http:\/\/local.wordpress.test\/wp-json\/wc\/store\/cart\/coupons\/20off"
+        }
+      ],
+      "collection": [
+        {
+          "href": "http:\/\/local.wordpress.test\/wp-json\/wc\/store\/cart\/coupons"
+        }
+      ]
+    }
+  }
+]
+```
+
+### Single cart coupon
+
+Get a single cart coupon.
+
+```http
+GET /cart/coupons/:code
+```
+
+| Attribute | Type   | Required | Description                                     |
+| :-------- | :----- | :------: | :---------------------------------------------- |
+| `code`    | string |   Yes    | The coupon code of the cart coupon to retrieve. |
+
+```http
+curl "https://example-store.com/wp-json/wc/store/cart/coupons/20off"
+```
+
+Example response:
+
+```json
+{
+  "code": "20off",
+  "totals": {
+    "currency_code": "GBP",
+    "currency_symbol": "£",
+    "currency_minor_unit": 2,
+    "currency_decimal_separator": ".",
+    "currency_thousand_separator": ",",
+    "currency_prefix": "£",
+    "currency_suffix": "",
+    "total_discount": "1667",
+    "total_discount_tax": "333"
+  }
+}
+```
+
+### New cart coupon
+
+Apply a coupon to the cart.
+
+```http
+POST /cart/coupons/
+```
+
+| Attribute | Type   | Required | Description                                    |
+| :-------- | :----- | :------: | :--------------------------------------------- |
+| `code`    | string |   Yes    | The coupon code you wish to apply to the cart. |
+
+```http
+curl --request POST https://example-store.com/wp-json/wc/store/cart/coupons?code=20off
+```
+
+Example response:
+
+```json
+{
+  "code": "20off",
+  "totals": {
+    "currency_code": "GBP",
+    "currency_symbol": "£",
+    "currency_minor_unit": 2,
+    "currency_decimal_separator": ".",
+    "currency_thousand_separator": ",",
+    "currency_prefix": "£",
+    "currency_suffix": "",
+    "total_discount": "1667",
+    "total_discount_tax": "333"
+  }
+}
+```
+
+### Delete single cart coupon
+
+Delete/remove a coupon from the cart.
+
+```http
+DELETE /cart/coupons/:code
+```
+
+| Attribute | Type   | Required | Description                                       |
+| :-------- | :----- | :------: | :------------------------------------------------ |
+| `code`    | string |   Yes    | The coupon code you wish to remove from the cart. |
+
+```http
+curl --request DELETE https://example-store.com/wp-json/wc/store/cart/coupons/20off
+```
+
+### Delete all cart coupons
+
+Delete/remove all coupons from the cart.
+
+```http
+DELETE /cart/coupons/
+```
+
+There are no parameters required for this endpoint.
+
+```http
+curl --request DELETE https://example-store.com/wp-json/wc/store/cart/coupons
+```
+
+Example response:
+
+```json
+[]
+```
+
 ## Cart shipping rates API
 
 ### Get shipping rates for current cart
diff --git a/plugins/woocommerce-blocks/src/RestApi/StoreApi/Schemas/CartCouponSchema.php b/plugins/woocommerce-blocks/src/RestApi/StoreApi/Schemas/CartCouponSchema.php
new file mode 100644
index 00000000000..51e33246c88
--- /dev/null
+++ b/plugins/woocommerce-blocks/src/RestApi/StoreApi/Schemas/CartCouponSchema.php
@@ -0,0 +1,102 @@
+<?php
+/**
+ * Cart Coupon Schema.
+ *
+ * @package WooCommerce/Blocks
+ */
+
+namespace Automattic\WooCommerce\Blocks\RestApi\StoreApi\Schemas;
+
+defined( 'ABSPATH' ) || exit;
+
+use Automattic\WooCommerce\Blocks\RestApi\StoreApi\Utilities\CartController;
+
+/**
+ * CartCouponSchema class.
+ *
+ * @since 2.5.0
+ */
+class CartCouponSchema extends AbstractSchema {
+	/**
+	 * The schema item name.
+	 *
+	 * @var string
+	 */
+	protected $title = 'cart_coupon';
+
+	/**
+	 * Cart schema properties.
+	 *
+	 * @return array
+	 */
+	protected function get_properties() {
+		return [
+			'code'   => [
+				'description' => __( 'The coupons unique code.', 'woo-gutenberg-products-block' ),
+				'type'        => 'string',
+				'context'     => [ 'view', 'edit' ],
+				'arg_options' => [
+					'sanitize_callback' => 'wc_format_coupon_code',
+					'validate_callback' => [ $this, 'coupon_exists' ],
+				],
+			],
+			'totals' => [
+				'description' => __( 'Total amounts provided using the smallest unit of the currency.', 'woo-gutenberg-products-block' ),
+				'type'        => 'object',
+				'context'     => [ 'view', 'edit' ],
+				'readonly'    => true,
+				'properties'  => array_merge(
+					$this->get_store_currency_properties(),
+					[
+						'total_discount'     => [
+							'description' => __( 'Total discount applied by this coupon.', 'woo-gutenberg-products-block' ),
+							'type'        => 'string',
+							'context'     => [ 'view', 'edit' ],
+							'readonly'    => true,
+						],
+						'total_discount_tax' => [
+							'description' => __( 'Total tax removed due to discount applied by this coupon.', 'woo-gutenberg-products-block' ),
+							'type'        => 'string',
+							'context'     => [ 'view', 'edit' ],
+							'readonly'    => true,
+						],
+					]
+				),
+			],
+		];
+	}
+
+	/**
+	 * Check given coupon exists.
+	 *
+	 * @param string $coupon_code Coupon code.
+	 * @return bool
+	 */
+	public function coupon_exists( $coupon_code ) {
+		$coupon = new \WC_Coupon( $coupon_code );
+		return (bool) $coupon->get_id() || $coupon->get_virtual();
+	}
+
+	/**
+	 * Convert a WooCommerce cart item to an object suitable for the response.
+	 *
+	 * @param string $coupon_code Coupon code from the cart.
+	 * @return array
+	 */
+	public function get_item_response( $coupon_code ) {
+		$controller           = new CartController();
+		$cart                 = $controller->get_cart_instance();
+		$total_discounts      = $cart->get_coupon_discount_totals();
+		$total_discount_taxes = $cart->get_coupon_discount_tax_totals();
+		return [
+			'code'   => $coupon_code,
+			'totals' => array_merge(
+				$this->get_store_currency_response(),
+				[
+					'total_discount'     => $this->prepare_money_response( isset( $total_discounts[ $coupon_code ] ) ? $total_discounts[ $coupon_code ] : 0, wc_get_price_decimals() ),
+					'total_discount_tax' => $this->prepare_money_response( isset( $total_discount_taxes[ $coupon_code ] ) ? $total_discount_taxes[ $coupon_code ] : 0, wc_get_price_decimals(), PHP_ROUND_HALF_DOWN ),
+				]
+			),
+		];
+	}
+}
diff --git a/plugins/woocommerce-blocks/src/RestApi/StoreApi/Schemas/CartItemSchema.php b/plugins/woocommerce-blocks/src/RestApi/StoreApi/Schemas/CartItemSchema.php
index e5764add541..b0269a21ede 100644
--- a/plugins/woocommerce-blocks/src/RestApi/StoreApi/Schemas/CartItemSchema.php
+++ b/plugins/woocommerce-blocks/src/RestApi/StoreApi/Schemas/CartItemSchema.php
@@ -1,8 +1,6 @@
 <?php
 /**
- * Abstract Schema.
- *
- * Rest API schema class.
+ * Cart Item Schema.
  *
  * @package WooCommerce/Blocks
  */
@@ -14,7 +12,7 @@ defined( 'ABSPATH' ) || exit;
 use Automattic\WooCommerce\Blocks\RestApi\Utilities\ProductImages;
 
 /**
- * AbstractBlock class.
+ * CartItemSchema class.
  *
  * @since 2.5.0
  */
diff --git a/plugins/woocommerce-blocks/src/RestApi/StoreApi/Schemas/CartSchema.php b/plugins/woocommerce-blocks/src/RestApi/StoreApi/Schemas/CartSchema.php
index 9e77e8fe6e6..b087fd535e5 100644
--- a/plugins/woocommerce-blocks/src/RestApi/StoreApi/Schemas/CartSchema.php
+++ b/plugins/woocommerce-blocks/src/RestApi/StoreApi/Schemas/CartSchema.php
@@ -29,6 +29,16 @@ class CartSchema extends AbstractSchema {
 	 */
 	protected function get_properties() {
 		return [
+			'coupons'        => [
+				'description' => __( 'List of applied cart coupons.', 'woo-gutenberg-products-block' ),
+				'type'        => 'array',
+				'context'     => [ 'view', 'edit' ],
+				'readonly'    => true,
+				'items'       => [
+					'type'       => 'object',
+					'properties' => $this->force_schema_readonly( ( new CartCouponSchema() )->get_properties() ),
+				],
+			],
 			'items'          => [
 				'description' => __( 'List of cart items.', 'woo-gutenberg-products-block' ),
 				'type'        => 'array',
@@ -161,8 +171,10 @@ class CartSchema extends AbstractSchema {
 	 * @return array
 	 */
 	public function get_item_response( $cart ) {
-		$cart_item_schema = new CartItemSchema();
+		$cart_coupon_schema = new CartCouponSchema();
+		$cart_item_schema   = new CartItemSchema();
 		return [
+			'coupons'        => array_values( array_map( [ $cart_coupon_schema, 'get_item_response' ], array_filter( $cart->get_applied_coupons() ) ) ),
 			'items'          => array_values( array_map( [ $cart_item_schema, 'get_item_response' ], array_filter( $cart->get_cart() ) ) ),
 			'items_count'    => $cart->get_cart_contents_count(),
 			'items_weight'   => wc_get_weight( $cart->get_cart_contents_weight(), 'g' ),
diff --git a/plugins/woocommerce-blocks/src/RestApi/StoreApi/Utilities/CartController.php b/plugins/woocommerce-blocks/src/RestApi/StoreApi/Utilities/CartController.php
index 54747f1f57c..cce572dc105 100644
--- a/plugins/woocommerce-blocks/src/RestApi/StoreApi/Utilities/CartController.php
+++ b/plugins/woocommerce-blocks/src/RestApi/StoreApi/Utilities/CartController.php
@@ -2,8 +2,6 @@
 /**
  * Helper class to bridge the gap between the cart API and Woo core.
  *
- * Overrides some of the woo core cart methods to make them work with the API and generally increase flexibility. Some of this logic should move to core.
- *
  * @package WooCommerce/Blocks
  */
 
@@ -24,6 +22,10 @@ class CartController {
 	/**
 	 * Based on the core cart class but returns errors rather than rendering notices directly.
 	 *
+	 * @todo Overriding the core add_to_cart method was necessary because core outputs notices when an item is added to
+	 * the cart. For us this would cause notices to build up and output on the store, out of context. Core would need
+	 * refactoring to split notices out from other cart actions.
+	 *
 	 * @throws RestException Exception if invalid data is detected.
 	 *
 	 * @param array $request Add to cart request params.
@@ -52,21 +54,44 @@ class CartController {
 				$variation_id = 0;
 			}
 
-			$cart_id          = wc()->cart->generate_cart_id( $product_id, $variation_id, $request['variation'], $request['cart_item_data'] );
+			$cart_id          = wc()->cart->generate_cart_id(
+				$product_id,
+				$variation_id,
+				$request['variation'],
+				$request['cart_item_data']
+			);
 			$existing_cart_id = wc()->cart->find_product_in_cart( $cart_id );
 
 			if ( ! $product->is_purchasable() ) {
-				throw new RestException( 'woocommerce_rest_cart_product_is_not_purchasable', __( 'This product cannot be purchased.', 'woo-gutenberg-products-block' ), 403 );
+				throw new RestException(
+					'woocommerce_rest_cart_product_is_not_purchasable',
+					__( 'This product cannot be purchased.', 'woo-gutenberg-products-block' ),
+					403
+				);
 			}
 
 			if ( $product->is_sold_individually() && $existing_cart_id ) {
-				/* translators: %s: product name */
-				throw new RestException( 'woocommerce_rest_cart_product_sold_individually', sprintf( __( '"%s" is already inside your cart.', 'woo-gutenberg-products-block' ), $product->get_name() ), 403 );
+				throw new RestException(
+					'woocommerce_rest_cart_product_sold_individually',
+					sprintf(
+						/* translators: %s: product name */
+						__( '"%s" is already inside your cart.', 'woo-gutenberg-products-block' ),
+						$product->get_name()
+					),
+					403
+				);
 			}
 
 			if ( ! $product->is_in_stock() ) {
-				/* translators: %s: product name */
-				throw new RestException( 'woocommerce_rest_cart_product_no_stock', sprintf( __( 'You cannot add &quot;%s&quot; to the cart because the product is out of stock.', 'woo-gutenberg-products-block' ), $product->get_name() ), 403 );
+				throw new RestException(
+					'woocommerce_rest_cart_product_no_stock',
+					sprintf(
+						/* translators: %s: product name */
+						__( 'You cannot add &quot;%s&quot; to the cart because the product is out of stock.', 'woo-gutenberg-products-block' ),
+						$product->get_name()
+					),
+					403
+				);
 			}
 
 			if ( $product->managing_stock() ) {
@@ -112,7 +137,15 @@ class CartController {
 
 			wc()->cart->cart_contents = apply_filters( 'woocommerce_cart_contents_changed', wc()->cart->cart_contents );
 
-			do_action( 'woocommerce_add_to_cart', $cart_id, $product_id, $request['quantity'], $variation_id, $request['variation'], $request['cart_item_data'] );
+			do_action(
+				'woocommerce_add_to_cart',
+				$cart_id,
+				$product_id,
+				$request['quantity'],
+				$variation_id,
+				$request['variation'],
+				$request['cart_item_data']
+			);
 
 			return $cart_id;
 		} catch ( RestException $e ) {
@@ -156,6 +189,104 @@ class CartController {
 		wc()->cart->empty_cart();
 	}
 
+	/**
+	 * See if cart has applied coupon by code.
+	 *
+	 * @param string $coupon_code Cart coupon code.
+	 * @return bool
+	 */
+	public function has_coupon( $coupon_code ) {
+		return wc()->cart->has_discount( $coupon_code );
+	}
+
+	/**
+	 * Returns all applied coupons.
+	 *
+	 * @param callable $callback Optional callback to apply to the array filter.
+	 * @return array
+	 */
+	public function get_cart_coupons( $callback = null ) {
+		return $callback ? array_filter( wc()->cart->get_applied_coupons(), $callback ) : array_filter( wc()->cart->get_applied_coupons() );
+	}
+
+	/**
+	 * Based on the core cart class but returns errors rather than rendering notices directly.
+	 *
+	 * @todo Overriding the core apply_coupon method was necessary because core outputs notices when a coupon gets
+	 * applied. For us this would cause notices to build up and output on the store, out of context. Core would need
+	 * refactoring to split notices out from other cart actions.
+	 *
+	 * @throws RestException Exception if invalid data is detected.
+	 *
+	 * @param string $coupon_code Coupon code.
+	 */
+	public function apply_coupon( $coupon_code ) {
+		$cart            = $this->get_cart_instance();
+		$applied_coupons = $this->get_cart_coupons();
+		$coupon          = new \WC_Coupon( $coupon_code );
+
+		if ( $coupon->get_code() !== $coupon_code ) {
+			throw new RestException(
+				'woocommerce_rest_cart_coupon_error',
+				__( 'Invalid coupon code.', 'woo-gutenberg-products-block' ),
+				403
+			);
+		}
+
+		if ( $this->has_coupon( $coupon_code ) ) {
+			throw new RestException(
+				'woocommerce_rest_cart_coupon_error',
+				__( 'Coupon has already been applied.', 'woo-gutenberg-products-block' ),
+				403
+			);
+		}
+
+		if ( ! $coupon->is_valid() ) {
+			throw new RestException(
+				'woocommerce_rest_cart_coupon_error',
+				$coupon->get_error_message(),
+				403
+			);
+		}
+
+		// Prevents new coupons being added if individual use coupons are already in the cart.
+		$individual_use_coupons = $this->get_cart_coupons(
+			function( $code ) {
+				$coupon = new \WC_Coupon( $code );
+				return $coupon->get_individual_use();
+			}
+		);
+
+		foreach ( $individual_use_coupons as $code ) {
+			$individual_use_coupon = new \WC_Coupon( $code );
+
+			if ( false === apply_filters( 'woocommerce_apply_with_individual_use_coupon', false, $coupon, $individual_use_coupon, $applied_coupons ) ) {
+				throw new RestException(
+					'woocommerce_rest_cart_coupon_error',
+					sprintf(
+						/* translators: %s: coupon code */
+						__( '"%s" has already been applied and cannot be used in conjunction with other coupons.', 'woo-gutenberg-products-block' ),
+						$code
+					),
+					403
+				);
+			}
+		}
+
+		if ( $coupon->get_individual_use() ) {
+			$coupons_to_remove = array_diff( $applied_coupons, apply_filters( 'woocommerce_apply_individual_use_coupon', array(), $coupon, $applied_coupons ) );
+
+			foreach ( $coupons_to_remove as $code ) {
+				$cart->remove_coupon( $code );
+			}
+		}
+
+		$applied_coupons[] = $coupon_code;
+		$cart->set_applied_coupons( $applied_coupons );
+
+		do_action( 'woocommerce_applied_coupon', $coupon_code );
+	}
+
 	/**
 	 * Get a product object to be added to the cart.
 	 *
@@ -168,7 +299,11 @@ class CartController {
 		$product = wc_get_product( $request['id'] );
 
 		if ( ! $product || 'trash' === $product->get_status() ) {
-			throw new RestException( 'woocommerce_rest_cart_invalid_product', __( 'This product cannot be added to the cart.', 'woo-gutenberg-products-block' ), 403 );
+			throw new RestException(
+				'woocommerce_rest_cart_invalid_product',
+				__( 'This product cannot be added to the cart.', 'woo-gutenberg-products-block' ),
+				403
+			);
 		}
 
 		return $product;
@@ -297,7 +432,11 @@ class CartController {
 		$variation_id     = $data_store->find_matching_product_variation( $product, $match_attributes );
 
 		if ( empty( $variation_id ) ) {
-			throw new RestException( 'woocommerce_rest_variation_id_from_variation_data', __( 'No matching variation found.', 'woo-gutenberg-products-block' ), 400 );
+			throw new RestException(
+				'woocommerce_rest_variation_id_from_variation_data',
+				__( 'No matching variation found.', 'woo-gutenberg-products-block' ),
+				400
+			);
 		}
 
 		return $variation_id;
@@ -321,17 +460,36 @@ class CartController {
 			if ( ! $attribute['is_variation'] ) {
 				continue;
 			}
-			$attribute_label = wc_attribute_label( $attribute['name'] );
+			$attribute_label          = wc_attribute_label( $attribute['name'] );
+			$variation_attribute_name = wc_variation_attribute_name( $attribute['name'] );
 
 			// Attribute labels e.g. Size.
 			if ( isset( $variation_data[ $attribute_label ] ) ) {
-				$return[ wc_variation_attribute_name( $attribute['name'] ) ] = $attribute['is_taxonomy'] ? sanitize_title( $variation_data[ $attribute_label ] ) : html_entity_decode( wc_clean( $variation_data[ $attribute_label ] ), ENT_QUOTES, get_bloginfo( 'charset' ) );
+				$return[ $variation_attribute_name ] =
+					$attribute['is_taxonomy']
+						?
+						sanitize_title( $variation_data[ $attribute_label ] )
+						:
+						html_entity_decode(
+							wc_clean( $variation_data[ $attribute_label ] ),
+							ENT_QUOTES,
+							get_bloginfo( 'charset' )
+						);
 				continue;
 			}
 
 			// Attribute slugs e.g. pa_size.
 			if ( isset( $variation_data[ $attribute['name'] ] ) ) {
-				$return[ wc_variation_attribute_name( $attribute['name'] ) ] = $attribute['is_taxonomy'] ? sanitize_title( $variation_data[ $attribute['name'] ] ) : html_entity_decode( wc_clean( $variation_data[ $attribute['name'] ] ), ENT_QUOTES, get_bloginfo( 'charset' ) );
+				$return[ $variation_attribute_name ] =
+					$attribute['is_taxonomy']
+						?
+						sanitize_title( $variation_data[ $attribute['name'] ] )
+						:
+						html_entity_decode(
+							wc_clean( $variation_data[ $attribute['name'] ] ),
+							ENT_QUOTES,
+							get_bloginfo( 'charset' )
+						);
 			}
 		}
 		return $return;
@@ -351,7 +509,11 @@ class CartController {
 		}
 
 		if ( ! $product || 'trash' === $product->get_status() ) {
-			throw new RestException( 'woocommerce_rest_cart_invalid_parent_product', __( 'This product cannot be added to the cart.', 'woo-gutenberg-products-block' ), 403 );
+			throw new RestException(
+				'woocommerce_rest_cart_invalid_parent_product',
+				__( 'This product cannot be added to the cart.', 'woo-gutenberg-products-block' ),
+				403
+			);
 		}
 
 		return $product->get_attributes();
diff --git a/plugins/woocommerce-blocks/tests/php/RestApi/StoreApi/Controllers/CartCoupons.php b/plugins/woocommerce-blocks/tests/php/RestApi/StoreApi/Controllers/CartCoupons.php
new file mode 100644
index 00000000000..b531f895964
--- /dev/null
+++ b/plugins/woocommerce-blocks/tests/php/RestApi/StoreApi/Controllers/CartCoupons.php
@@ -0,0 +1,169 @@
+<?php
+/**
+ * Controller Tests.
+ *
+ * @package WooCommerce\Blocks\Tests
+ */
+
+namespace Automattic\WooCommerce\Blocks\Tests\RestApi\StoreApi\Controllers;
+
+use \WP_REST_Request;
+use \WC_REST_Unit_Test_Case as TestCase;
+use \WC_Helper_Product as ProductHelper;
+use \WC_Helper_Coupon as CouponHelper;
+
+/**
+ * Cart Coupons Controller Tests.
+ */
+class CartCoupons extends TestCase {
+	/**
+	 * Setup test products data. Called before every test.
+	 */
+	public function setUp() {
+		parent::setUp();
+
+		wp_set_current_user( 0 );
+
+		$this->product = ProductHelper::create_simple_product( false );
+		$this->coupon  = CouponHelper::create_coupon();
+
+		wc_empty_cart();
+
+		wc()->cart->add_to_cart( $this->product->get_id(), 2 );
+		wc()->cart->apply_coupon( $this->coupon->get_code() );
+	}
+
+	/**
+	 * Test route registration.
+	 */
+	public function test_register_routes() {
+		$routes = $this->server->get_routes();
+		$this->assertArrayHasKey( '/wc/store/cart/coupons', $routes );
+		$this->assertArrayHasKey( '/wc/store/cart/coupons/(?P<code>[\w-]+)', $routes );
+	}
+
+	/**
+	 * Test getting cart.
+	 */
+	public function test_get_items() {
+		$response = $this->server->dispatch( new WP_REST_Request( 'GET', '/wc/store/cart/coupons' ) );
+		$data     = $response->get_data();
+
+		$this->assertEquals( 200, $response->get_status() );
+		$this->assertEquals( 1, count( $data ) );
+	}
+
+	/**
+	 * Test getting cart item by key.
+	 */
+	public function test_get_item() {
+		$response = $this->server->dispatch( new WP_REST_Request( 'GET', '/wc/store/cart/coupons/' . $this->coupon->get_code() ) );
+		$data     = $response->get_data();
+
+		$this->assertEquals( 200, $response->get_status() );
+		$this->assertEquals( $this->coupon->get_code(), $data['code'] );
+		$this->assertEquals( '0', $data['totals']['total_discount'] );
+		$this->assertEquals( '0', $data['totals']['total_discount_tax'] );
+	}
+
+	/**
+	 * Test add to cart.
+	 */
+	public function test_create_item() {
+		wc()->cart->remove_coupons();
+
+		$request = new WP_REST_Request( 'POST', '/wc/store/cart/coupons' );
+		$request->set_body_params(
+			array(
+				'code' => $this->coupon->get_code(),
+			)
+		);
+		$response = $this->server->dispatch( $request );
+		$data     = $response->get_data();
+
+		$this->assertEquals( 201, $response->get_status() );
+		$this->assertEquals( $this->coupon->get_code(), $data['code'] );
+	}
+
+	/**
+	 * Test add to cart does not allow invalid items.
+	 */
+	public function test_invalid_create_item() {
+		wc()->cart->remove_coupons();
+
+		$request = new WP_REST_Request( 'POST', '/wc/store/cart/coupons' );
+		$request->set_body_params(
+			array(
+				'code' => 'IDONOTEXIST',
+			)
+		);
+		$response = $this->server->dispatch( $request );
+		$data     = $response->get_data();
+
+		$this->assertEquals( 400, $response->get_status() );
+	}
+
+	/**
+	 * Test delete item.
+	 */
+	public function test_delete_item() {
+		$request  = new WP_REST_Request( 'DELETE', '/wc/store/cart/coupons/' . $this->coupon->get_code() );
+		$response = $this->server->dispatch( $request );
+		$data     = $response->get_data();
+
+		$this->assertEquals( 204, $response->get_status() );
+		$this->assertEmpty( $data );
+
+		$request  = new WP_REST_Request( 'DELETE', '/wc/store/cart/coupons/' . $this->coupon->get_code() );
+		$response = $this->server->dispatch( $request );
+		$data     = $response->get_data();
+
+		$this->assertEquals( 404, $response->get_status() );
+
+		$request  = new WP_REST_Request( 'DELETE', '/wc/store/cart/coupons/i-do-not-exist' );
+		$response = $this->server->dispatch( $request );
+		$data     = $response->get_data();
+
+		$this->assertEquals( 404, $response->get_status() );
+	}
+
+	/**
+	 * Test delete all items.
+	 */
+	public function test_delete_items() {
+		$request  = new WP_REST_Request( 'DELETE', '/wc/store/cart/coupons' );
+		$response = $this->server->dispatch( $request );
+		$data     = $response->get_data();
+
+		$this->assertEquals( 200, $response->get_status() );
+		$this->assertEquals( [], $data );
+
+		$response = $this->server->dispatch( new WP_REST_Request( 'GET', '/wc/store/cart/coupons' ) );
+		$data     = $response->get_data();
+
+		$this->assertEquals( 200, $response->get_status() );
+		$this->assertEquals( 0, count( $data ) );
+	}
+
+	/**
+	 * Test schema retrieval.
+	 */
+	public function test_get_item_schema() {
+		$controller = new \Automattic\WooCommerce\Blocks\RestApi\StoreApi\Controllers\CartCoupons();
+		$schema     = $controller->get_item_schema();
+
+		$this->assertArrayHasKey( 'code', $schema['properties'] );
+		$this->assertArrayHasKey( 'totals', $schema['properties'] );
+	}
+
+	/**
+	 * Test conversion of cart item to rest response.
+	 */
+	public function test_prepare_item_for_response() {
+		$controller = new \Automattic\WooCommerce\Blocks\RestApi\StoreApi\Controllers\CartCoupons();
+		$response   = $controller->prepare_item_for_response( $this->coupon->get_code(), [] );
+
+		$this->assertArrayHasKey( 'code', $response->get_data() );
+		$this->assertArrayHasKey( 'totals', $response->get_data() );
+	}
+}