# CartLinesAddPayload

Payload returned by the cartLinesAdd mutation. This type contains the updated cart information and any errors that occurred during the cart lines addition operation.

## Type Definition

```graphql
type CartLinesAddPayload {
  cart: Cart
  userErrors: [UserError]!
}
```

## Fields

| Field | Type | Description |
|-------|------|-------------|
| cart | Cart | The updated cart |
| userErrors | [UserError]! | List of errors that occurred during cart lines addition |

## Relationships

CartLinesAddPayload is the return type for the cartLinesAdd mutation. It contains a Cart object representing the updated shopping cart state after line items have been added. The userErrors field provides validation and operation error details as UserError objects.

## Example

```graphql
mutation {
  cartLinesAdd(cartId: "eyJhbGciOiJIUzI1NiJ9...", lines: [{merchandiseId: "12345", quantity: 1}]) {
    cart {
      id
      lines {
        edges {
          node {
            id
            quantity
          }
        }
      }
    }
    userErrors {
      field
      message
    }
  }
}
```

## Implements

This type does not implement any interfaces.

## Related Types

- [Cart](/reference/storefront/1.3.0/objects/cart)
- [UserError](/reference/storefront/1.3.0/objects/user-error)