create_variants

Instructions

Implementation Reference

• src/tools/variants.ts:319-351 (handler)

  The tool handler for 'create_variants'. Receives productId, variants (array of variantCreateSchema), and optional strategy. Calls the VARIANTS_BULK_CREATE_MUTATION GraphQL mutation and returns formatted results.

  server.tool(
    "create_variants",
    "Create one or more variants on an existing product. Each variant's optionValues must cover EVERY option declared on the product (Size + Color + Material if there are 3 options) — partial coverage is rejected. New products from create_product start with a single hidden 'Default Title' variant; when adding the first real variants, pass strategy='REMOVE_STANDALONE_VARIANT' so Shopify replaces the placeholder rather than leaving it. inventoryQuantities seeds initial stock per location at create time; for ongoing changes use set_inventory_quantity instead.",
    createVariantsSchema,
    async (args) => {
      const data = await client.graphql<{
        productVariantsBulkCreate: {
          productVariants: VariantNode[];
          userErrors: ShopifyUserError[];
        };
      }>(VARIANTS_BULK_CREATE_MUTATION, {
        productId: args.productId,
        variants: args.variants,
        strategy: args.strategy,
      });
      throwIfUserErrors(
        data.productVariantsBulkCreate.userErrors,
        "productVariantsBulkCreate",
      );
      const created = data.productVariantsBulkCreate.productVariants;
      return {
        content: [
          {
            type: "text" as const,
            text: [
              `Created ${created.length} variant(s):`,
              ...created.map((v) => formatVariant(v)),
            ].join("\n"),
          },
        ],
      };
    },
  );

• src/tools/variants.ts:198-207 (schema)

  Input schema (createVariantsSchema) for the tool. productId (string), variants (array of variantCreateSchema with 1-100 items), strategy (optional enum: DEFAULT|REMOVE_STANDALONE_VARIANT).

  const createVariantsSchema = {
    productId: z.string().describe("Product GID."),
    variants: z.array(variantCreateSchema).min(1).max(100),
    strategy: z
      .enum(["DEFAULT", "REMOVE_STANDALONE_VARIANT"])
      .optional()
      .describe(
        "DEFAULT: add to existing variants. REMOVE_STANDALONE_VARIANT: replace the auto-created 'Default Title' variant (use on first real variant create).",
      ),
  };

• src/tools/variants.ts:157-180 (helper)

  The variantCreateSchema defining the shape of each variant in the variants array: optionValues, price, compareAtPrice, sku, barcode, taxable, inventoryPolicy, inventoryQuantities.

  const variantCreateSchema = z.object({
    optionValues: z
      .array(optionValueInputSchema)
      .describe(
        "One entry per product option. Shape must match the product's options (order-insensitive, matched by optionName).",
      ),
    price: z.string().describe("Variant price as decimal string, e.g. '19.99'."),
    compareAtPrice: z.string().optional(),
    sku: z.string().optional(),
    barcode: z.string().optional(),
    taxable: z.boolean().optional(),
    inventoryPolicy: z
      .enum(["DENY", "CONTINUE"])
      .optional()
      .describe(
        "Oversell policy: DENY blocks sales at 0 stock, CONTINUE allows backorder.",
      ),
    inventoryQuantities: z
      .array(inventoryQuantityInputSchema)
      .optional()
      .describe(
        "Initial stock per location. Only accepted on create — use set_inventory_quantity for subsequent updates.",
      ),
  });

• src/tools/variants.ts:61-82 (helper)

  The GraphQL mutation (VARIANTS_BULK_CREATE_MUTATION) used by the create_variants handler to perform the bulk create operation.

  const VARIANTS_BULK_CREATE_MUTATION = /* GraphQL */ `
    mutation VariantsBulkCreate(
      $productId: ID!
      $variants: [ProductVariantsBulkInput!]!
      $strategy: ProductVariantsBulkCreateStrategy
    ) {
      productVariantsBulkCreate(
        productId: $productId
        variants: $variants
        strategy: $strategy
      ) {
        productVariants {
          id
          title
          price
          sku
          selectedOptions { name value }
        }
        userErrors { field message }
      }
    }
  `;

• src/server.ts:56-64 (registration)

  Registration of all variant tools (including create_variants) in the MCP server via registerVariantTools(s, shopify).

  const s = new McpServer({ name: "shopify-mcp", version: "0.1.0" });
  registerProductTools(s, shopify);
  registerOrderTools(s, shopify);
  registerInventoryTools(s, shopify);
  registerCustomerTools(s, shopify);
  registerMetafieldTools(s, shopify);
  registerDraftOrderTools(s, shopify);
  registerCollectionTools(s, shopify);
  registerVariantTools(s, shopify);