> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.bigcommerce.com/_mcp/server.

# Unions

> Build amazing commerce solutions powered by the BigCommerce platform


## API Docs

- Unions [AddCustomerAddressError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/add-customer-address-error.md)
- Unions [AddProductReviewError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/add-product-review-error.md)
- Unions [ApplyMcpSessionSyncCodeError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/apply-mcp-session-sync-code-error.md)
- Unions [CartUnassignError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/cart-unassign-error.md)
- Unions [ChangePasswordError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/change-password-error.md)
- Unions [ClientConfiguration](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/client-configuration.md)
- Unions [CompleteCheckoutError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/complete-checkout-error.md)
- Unions [CreateCartMetafieldError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/create-cart-metafield-error.md)
- Unions [CreateCartRedirectUrlsError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/create-cart-redirect-urls-error.md)
- Unions [CreateCheckoutError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/create-checkout-error.md)
- Unions [CreateCompanyUserError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/create-company-user-error.md)
- Unions [CreatePaymentWalletIntentError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/create-payment-wallet-intent-error.md)
- Unions [CreateSubscriberError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/create-subscriber-error.md)
- Unions [DeleteCartMetafieldError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/delete-cart-metafield-error.md)
- Unions [DeleteCustomerAddressError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/delete-customer-address-error.md)
- Unions [GenerateMcpSessionSyncTokenError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/generate-mcp-session-sync-token-error.md)
- Unions [GenerateSessionSyncTokenError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/generate-session-sync-token-error.md)
- Unions [GiftCertificatePreviewError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/gift-certificate-preview-error.md)
- Unions [OrderNonCouponShippingDiscount](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/order-non-coupon-shipping-discount.md)
- Unions [OrderShipmentTracking](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/order-shipment-tracking.md)
- Unions [PaymentInstrument](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/payment-instrument.md)
- Unions [PaymentWalletIntentData](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/payment-wallet-intent-data.md)
- Unions [RedirectTo](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/redirect-to.md)
- Unions [RegisterCompanyError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/register-company-error.md)
- Unions [RegisterCustomerError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/register-customer-error.md)
- Unions [RemoveSubscriberError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/remove-subscriber-error.md)
- Unions [RequestResetPasswordError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/request-reset-password-error.md)
- Unions [ResetPasswordError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/reset-password-error.md)
- Unions [StoredPaymentInstrumentDetails](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/stored-payment-instrument-details.md)
- Unions [StoreLogo](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/store-logo.md)
- Unions [SubmitContactUsError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/submit-contact-us-error.md)
- Unions [UpdateCartLocaleError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/update-cart-locale-error.md)
- Unions [UpdateCartMetafieldError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/update-cart-metafield-error.md)
- Unions [UpdateCheckoutError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/update-checkout-error.md)
- Unions [UpdateCustomerAddressError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/update-customer-address-error.md)
- Unions [UpdateCustomerError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/update-customer-error.md)
- Unions [ValidateSessionSyncJwtError](https://docs.bigcommerce.com/developer/api-reference/graphql/storefront/types/unions/validate-session-sync-jwt-error.md)