The GraphQL Storefront API now supports fetching the bulk pricing tiers on both products and variants.

Consider this query:

query bulkPricingTiers {
  site {
    products(first: 3) {
      edges {
        cursor
        node {
          entityId
          name
          prices {
            price {
              value
              currencyCode
            }
            bulkPricing {
              ... BulkPricingFields
            }
          }
          variants(first: 3) {
            edges {
              node {
                sku
                prices {
                  price {
                    value
                    currencyCode
                  }
                  bulkPricing {
                    ... BulkPricingFields
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

fragment BulkPricingFields on BulkPricingTier {
  minimumQuantity
  maximumQuantity
  ... on BulkPricingFixedPriceDiscount {
    price
  }
  ... on BulkPricingRelativePriceDiscount {
    priceAdjustment
  }
  ... on BulkPricingPercentageDiscount {
    percentOff
  }
}