Klaviyo MCP Server

Implementation Reference

• src/tools/lists.js:91-110 (handler)

  The asynchronous handler function that takes list_id and profile_ids, constructs a payload, posts to Klaviyo's API to add profiles to the list, and returns success or error message.

  async (params) => {
    try {
      const payload = {
        data: params.profile_ids.map(id => ({
          type: "profile",
          id
        }))
      };
      
      await klaviyoClient.post(`/lists/${params.list_id}/relationships/profiles/`, payload);
      return {
        content: [{ type: "text", text: "Profiles added to list successfully" }]
      };
    } catch (error) {
      return {
        content: [{ type: "text", text: `Error adding profiles to list: ${error.message}` }],
        isError: true
      };
    }
  },

• src/tools/lists.js:87-90 (schema)

  Zod schema for input validation: list_id as string and profile_ids as array of strings.

  {
    list_id: z.string().describe("ID of the list"),
    profile_ids: z.array(z.string()).describe("Array of profile IDs to add to the list")
  },

• src/tools/lists.js:85-112 (registration)

  Registration of the 'add_profiles_to_list' tool using server.tool, including schema, handler, and description within the registerListTools function.

  server.tool(
    "add_profiles_to_list",
    {
      list_id: z.string().describe("ID of the list"),
      profile_ids: z.array(z.string()).describe("Array of profile IDs to add to the list")
    },
    async (params) => {
      try {
        const payload = {
          data: params.profile_ids.map(id => ({
            type: "profile",
            id
          }))
        };
        
        await klaviyoClient.post(`/lists/${params.list_id}/relationships/profiles/`, payload);
        return {
          content: [{ type: "text", text: "Profiles added to list successfully" }]
        };
      } catch (error) {
        return {
          content: [{ type: "text", text: `Error adding profiles to list: ${error.message}` }],
          isError: true
        };
      }
    },
    { description: "Add profiles to a list in Klaviyo" }
  );