Shopify Update MCP Server

Instructions

Implementation Reference

• src/index.ts:271-301 (registration)

  Registration of the 'tag-customer' MCP tool including schema and inline handler that delegates to ShopifyClient.tagCustomer

  server.tool(
    "tag-customer",
    "Add tags to a customer",
    {
      customerId: z.string().describe("Customer ID to tag"),
      tags: z.array(z.string()).describe("Tags to add to the customer"),
    },
    async ({ customerId, tags }) => {
      const client = new ShopifyClient();
      try {
        const success = await client.tagCustomer(
          SHOPIFY_ACCESS_TOKEN,
          MYSHOPIFY_DOMAIN,
          tags,
          customerId
        );
        return {
          content: [
            {
              type: "text",
              text: success
                ? "Successfully tagged customer"
                : "Failed to tag customer",
            },
          ],
        };
      } catch (error) {
        return handleError("Failed to tag customer", error);
      }
    }
  );

• src/ShopifyClient/ShopifyClient.ts:1558-1609 (handler)

  Core handler implementation for tagging a customer using Shopify GraphQL 'tagsAdd' mutation

  async tagCustomer(
    accessToken: string,
    shop: string,
    tags: string[],
    externalCustomerId: string
  ): Promise<boolean> {
    const myshopifyDomain = await this.getMyShopifyDomain(accessToken, shop);
  
    const graphqlQuery = gql`
      mutation tagsAdd($id: ID!, $tags: [String!]!) {
        tagsAdd(id: $id, tags: $tags) {
          userErrors {
            field
            message
          }
          node {
            id
          }
        }
      }
    `;
  
    const res = await this.shopifyGraphqlRequest<{
      data: {
        tagsAdd: {
          userErrors: Array<{
            field: string[];
            message: string;
          }>;
          node: {
            id: string;
          };
        };
      };
    }>({
      url: `https://${myshopifyDomain}/admin/api/${this.SHOPIFY_API_VERSION}/graphql.json`,
      accessToken,
      query: graphqlQuery,
      variables: {
        id: `gid://shopify/Customer/${externalCustomerId}`,
        tags,
      },
    });
  
    const userErrors = res.data.data.tagsAdd.userErrors;
    if (userErrors.length > 0) {
      const errorMessages = userErrors.map((error) => error.message).join(", ");
      throw new Error(errorMessages);
    }
  
    return true;
  }

• src/index.ts:274-277 (schema)

  Input schema using Zod for customerId (string) and tags (array of strings)

  {
    customerId: z.string().describe("Customer ID to tag"),
    tags: z.array(z.string()).describe("Tags to add to the customer"),
  },

• src/ShopifyClient/ShopifyClientPort.ts:1032-1037 (helper)

  Interface definition for the tagCustomer method in ShopifyClientPort

  tagCustomer(
    accessToken: string,
    myshopifyDomain: string,
    tags: string[],
    customerId: string
  ): Promise<boolean>;

• src/index.ts:639-654 (helper)

  Utility function handleError used in the tool handler for error responses

  function handleError(
    defaultMessage: string,
    error: unknown
  ): {
    content: { type: "text"; text: string }[];
    isError: boolean;
  } {
    let errorMessage = defaultMessage;
    if (error instanceof CustomError) {
      errorMessage = `${defaultMessage}: ${error.message}`;
    }
    return {
      content: [{ type: "text", text: errorMessage }],
      isError: true,
    };
  }