Klaviyo MCP Server

Implementation Reference

• src/tools/lists.js:58-81 (handler)

  Executes the create_list tool by sending a POST request to Klaviyo's /lists/ endpoint with the provided name and list_type.

  async (params) => {
    try {
      const payload = {
        data: {
          type: "list",
          attributes: {
            name: params.name,
            list_type: params.list_type
          }
        }
      };
      
      const result = await klaviyoClient.post('/lists/', payload);
      return {
        content: [{ type: "text", text: JSON.stringify(result, null, 2) }]
      };
    } catch (error) {
      return {
        content: [{ type: "text", text: `Error creating list: ${error.message}` }],
        isError: true
      };
    }
  },
  { description: "Create a new list in Klaviyo" }

• src/tools/lists.js:54-57 (schema)

  Defines the input schema using Zod for the create_list tool parameters.

  {
    name: z.string().describe("Name of the list"),
    list_type: z.enum(["list", "segment"]).describe("Type of list (list or segment)")
  },

• src/tools/lists.js:52-82 (registration)

  Registers the create_list tool on the MCP server with its schema, handler, and description.

  server.tool(
    "create_list",
    {
      name: z.string().describe("Name of the list"),
      list_type: z.enum(["list", "segment"]).describe("Type of list (list or segment)")
    },
    async (params) => {
      try {
        const payload = {
          data: {
            type: "list",
            attributes: {
              name: params.name,
              list_type: params.list_type
            }
          }
        };
        
        const result = await klaviyoClient.post('/lists/', payload);
        return {
          content: [{ type: "text", text: JSON.stringify(result, null, 2) }]
        };
      } catch (error) {
        return {
          content: [{ type: "text", text: `Error creating list: ${error.message}` }],
          isError: true
        };
      }
    },
    { description: "Create a new list in Klaviyo" }
  );

• src/server.js:33-33 (registration)

  Invokes registerListTools to register all list tools, including create_list.

  registerListTools(server);