diff --git a/commercetools/commercetools-sdk-java-api/src/integrationTest/java/commercetools/custom_command/CartDecoratorTest.java b/commercetools/commercetools-sdk-java-api/src/integrationTest/java/commercetools/custom_command/CartDecoratorTest.java
new file mode 100644
index 00000000000..81e4a17bf90
--- /dev/null
+++ b/commercetools/commercetools-sdk-java-api/src/integrationTest/java/commercetools/custom_command/CartDecoratorTest.java
@@ -0,0 +1,118 @@
+
+package commercetools.custom_command;
+
+import java.net.URI;
+import java.time.Duration;
+import java.util.concurrent.CompletableFuture;
+import java.util.function.Function;
+
+import com.commercetools.api.client.ByProjectKeyCartsByIDPost;
+import com.commercetools.api.client.ProjectApiRoot;
+import com.commercetools.api.models.cart.*;
+import commercetools.utils.CommercetoolsTestUtils;
+
+import io.vrap.rmf.base.client.ApiHttpClient;
+import io.vrap.rmf.base.client.ApiHttpRequest;
+import io.vrap.rmf.base.client.ApiHttpResponse;
+import io.vrap.rmf.base.client.CreateHttpRequestCommand;
+import io.vrap.rmf.base.client.ResponseSerializer;
+
+import org.junit.jupiter.api.Test;
+
+public class CartDecoratorTest {
+    @Test
+    public void decoratedClient() {
+        final ProjectApiRoot apiRoot = CommercetoolsTestUtils.getProjectApiRoot();
+        final DecoratedApiHttpClient client = new DecoratedApiHttpClient(apiRoot.getApiHttpClient(), true);
+        final ProjectApiRoot decoratedRoot = ProjectApiRoot.fromClient(apiRoot.getProjectKey(), client);
+        final CartDraft cartDraft = CartDraftBuilder.of().currency("EUR").build();
+
+        final CartRecalculateAction cartRecalculateAction = CartUpdateActionBuilder.of().recalculateBuilder().build();
+        final CartChangeTaxModeAction cartChangeTaxModeAction = CartUpdateActionBuilder.of()
+                .changeTaxModeBuilder()
+                .taxMode(TaxMode.DISABLED)
+                .build();
+        final Cart cart = decoratedRoot.carts().create(cartDraft).execute().thenApply(ApiHttpResponse::getBody).join();
+        final Cart updatedCart = decoratedRoot.carts()
+                .withId(cart.getId())
+                .post(IncludeCartCartUpdateBuilder.of()
+                        .cart(cart)
+                        .version(cart.getVersion())
+                        .actions(cartRecalculateAction, cartChangeTaxModeAction)
+                        .build())
+                .execute()
+                .thenApply(ApiHttpResponse::getBody)
+                .join();
+    }
+
+    public static class DecoratedApiHttpClient implements ApiHttpClient {
+        private final ApiHttpClient apiHttpClient;
+
+        private ApiHttpRequest lastRequest;
+
+        private boolean enableResetLineItemExternalTotals;
+
+        public DecoratedApiHttpClient(ApiHttpClient apiHttpClient, boolean enableResetLineItemExternalTotals) {
+            this.apiHttpClient = apiHttpClient;
+            this.enableResetLineItemExternalTotals = enableResetLineItemExternalTotals;
+        }
+
+        @Override
+        public ResponseSerializer getSerializerService() {
+            return apiHttpClient.getSerializerService();
+        }
+
+        @Override
+        public URI getBaseUri() {
+            return apiHttpClient.getBaseUri();
+        }
+
+        @Override
+        public CompletableFuture<ApiHttpResponse<byte[]>> execute(ApiHttpRequest request) {
+            lastRequest = request;
+            return apiHttpClient.execute(request);
+        }
+
+        @Override
+        public <O> CompletableFuture<ApiHttpResponse<O>> execute(CreateHttpRequestCommand request,
+                Function<ApiHttpResponse<byte[]>, ApiHttpResponse<O>> mapper) {
+            return ApiHttpClient.super.execute(resetLineItemExternalTotals(request), mapper);
+        }
+
+        @Override
+        public <O> ApiHttpResponse<O> executeBlocking(CreateHttpRequestCommand method,
+                Function<ApiHttpResponse<byte[]>, ApiHttpResponse<O>> mapper, Duration timeout) {
+            return ApiHttpClient.super.executeBlocking(resetLineItemExternalTotals(method), mapper, timeout);
+        }
+
+        @Override
+        public CompletableFuture<ApiHttpResponse<byte[]>> send(CreateHttpRequestCommand method) {
+            return ApiHttpClient.super.send(resetLineItemExternalTotals(method));
+        }
+
+        @Override
+        public <T> ApiHttpResponse<byte[]> sendBlocking(CreateHttpRequestCommand method, Duration timeout) {
+            return ApiHttpClient.super.sendBlocking(resetLineItemExternalTotals(method), timeout);
+        }
+
+        @Override
+        public void close() throws Exception {
+            apiHttpClient.close();
+        }
+
+        public CreateHttpRequestCommand resetLineItemExternalTotals(CreateHttpRequestCommand method) {
+            if (enableResetLineItemExternalTotals && method instanceof ByProjectKeyCartsByIDPost) {
+                final ByProjectKeyCartsByIDPost byProjectKeyCartsByIDPost = (ByProjectKeyCartsByIDPost) method;
+                final CartUpdate cartUpdate = byProjectKeyCartsByIDPost.getBody();
+                if (cartUpdate instanceof WithCartCartUpdateImpl) {
+                    final WithCartCartUpdateImpl withCartCartUpdate = (WithCartCartUpdateImpl) cartUpdate;
+                    final Cart cart = withCartCartUpdate.getCart();
+
+                    // do sth with the cart
+                }
+            }
+
+            return method;
+        }
+    }
+}
diff --git a/commercetools/commercetools-sdk-java-api/src/integrationTest/java/commercetools/custom_command/IncludeCartCartUpdateBuilder.java b/commercetools/commercetools-sdk-java-api/src/integrationTest/java/commercetools/custom_command/IncludeCartCartUpdateBuilder.java
new file mode 100644
index 00000000000..cd15ff80c9d
--- /dev/null
+++ b/commercetools/commercetools-sdk-java-api/src/integrationTest/java/commercetools/custom_command/IncludeCartCartUpdateBuilder.java
@@ -0,0 +1,37 @@
+
+package commercetools.custom_command;
+
+import java.util.List;
+import java.util.Objects;
+
+import com.commercetools.api.models.cart.Cart;
+import com.commercetools.api.models.cart.CartUpdate;
+import com.commercetools.api.models.cart.CartUpdateAction;
+import com.commercetools.api.models.cart.CartUpdateBuilder;
+
+public class IncludeCartCartUpdateBuilder extends CartUpdateBuilder {
+    private Cart cart;
+
+    public Cart getCart() {
+        return cart;
+    }
+
+    public IncludeCartCartUpdateBuilder cart(Cart cart) {
+        this.cart = cart;
+        return this;
+    }
+
+    public static IncludeCartCartUpdateBuilder of() {
+        return new IncludeCartCartUpdateBuilder();
+    }
+
+    @Override
+    public CartUpdate build() {
+        final Long version = super.getVersion();
+        final List<CartUpdateAction> actions = super.getActions();
+        Objects.requireNonNull(version, CartUpdate.class + ": version is missing");
+        Objects.requireNonNull(actions, CartUpdate.class + ": actions is missing");
+        Objects.requireNonNull(cart, CartUpdate.class + ": cart is missing");
+        return new WithCartCartUpdateImpl(cart, version, actions);
+    }
+}
diff --git a/commercetools/commercetools-sdk-java-api/src/integrationTest/java/commercetools/custom_command/WithCartCartUpdateImpl.java b/commercetools/commercetools-sdk-java-api/src/integrationTest/java/commercetools/custom_command/WithCartCartUpdateImpl.java
new file mode 100644
index 00000000000..c1d49456ad0
--- /dev/null
+++ b/commercetools/commercetools-sdk-java-api/src/integrationTest/java/commercetools/custom_command/WithCartCartUpdateImpl.java
@@ -0,0 +1,24 @@
+
+package commercetools.custom_command;
+
+import com.commercetools.api.models.cart.Cart;
+
+public class WithCartCartUpdateImpl extends com.commercetools.api.models.cart.CartUpdateImpl {
+
+    private Cart cart;
+
+    public WithCartCartUpdateImpl(final Cart cart, final Long version,
+            final java.util.List<com.commercetools.api.models.cart.CartUpdateAction> actions) {
+        this.cart = cart;
+        super.setActions(actions);
+        super.setVersion(version);
+    }
+
+    public Cart getCart() {
+        return cart;
+    }
+
+    public void setCart(final Cart cart) {
+        this.cart = cart;
+    }
+}