Configurable Product GraphQl query

extend_schema.md

https://community.magento.com/t5/Magento-DevBlog/Optimizing-storefronts-with-GraphQL-in-Magento-2/ba-p/94196

productDetail.graphql

query productDetail($urlKey: String, $onServer: Boolean!) {
  productDetail: products(filter: {url_key: {eq: $urlKey}}) {
    items {
      sku
      name
      url_key
      small_image
      price {
        regularPrice {
          amount {
            currency
            value
          }
        }
      }
      description
      media_gallery_entries {
        label
        position
        disabled
        file
      }
      ... on ConfigurableProduct {
        configurable_options {
          attribute_code
          attribute_id
          id
          label
          values {
            default_label
            label
            store_label
            use_default_value
            value_index
          }
        }
        variants {
          product {
            id
            media_gallery_entries {
              disabled
              file
              label
              position
            }
            sku
            stock_status
          }
        }
      }
      meta_title @include(if: $onServer)
      meta_keyword @include(if: $onServer)
      meta_description @include(if: $onServer)
    }
  }
}