post:
  operationId: PostCartsCartLineItems
  summary: Add a Line Item
  description: Generates a Line Item with a given Product Variant and adds it to the Cart
  parameters:
    - in: path
      name: id
      required: true
      description: The id of the Cart to add the Line Item to.
      schema:
        type: string
  tags:
    - Cart
  responses:
    '200':
      description: OK
      content:
        application/json:
          schema:
            properties:
              cart:
                $ref: ../components/schemas/cart.yaml
  requestBody:
    content:
      application/json:
        schema:
          type: object
          required:
            - variant_id
            - quantity
          properties:
            variant_id:
              type: string
              description: The id of the Product Variant to generate the Line Item from.
            quantity:
              type: integer
              description: The quantity of the Product Variant to add to the Line Item.
            metadata:
              type: object
              description: >-
                An optional key-value map with additional details about the Line
                Item.