Klaviyo MCP Server

Implementation Reference

• src/tools/metrics.js:13-25 (handler)

  The handler function that implements the core logic of the 'get_metrics' tool by calling the Klaviyo API via klaviyoClient.get and formatting the response as MCP content or error.

  async (params) => {
    try {
      const metrics = await klaviyoClient.get('/metrics/', params);
      return {
        content: [{ type: "text", text: JSON.stringify(metrics, null, 2) }]
      };
    } catch (error) {
      return {
        content: [{ type: "text", text: `Error retrieving metrics: ${error.message}` }],
        isError: true
      };
    }
  },

• src/tools/metrics.js:8-12 (schema)

  Zod schema defining the input parameters for the 'get_metrics' tool: optional filter, page_size (1-100), and page_cursor.

  {
    filter: z.string().optional().describe("Filter query for metrics"),
    page_size: z.number().min(1).max(100).optional().describe("Number of metrics per page (1-100)"),
    page_cursor: z.string().optional().describe("Cursor for pagination")
  },

• src/tools/metrics.js:6-27 (registration)

  The server.tool call that registers the 'get_metrics' tool, including its name, input schema, handler function, and description.

  server.tool(
    "get_metrics",
    {
      filter: z.string().optional().describe("Filter query for metrics"),
      page_size: z.number().min(1).max(100).optional().describe("Number of metrics per page (1-100)"),
      page_cursor: z.string().optional().describe("Cursor for pagination")
    },
    async (params) => {
      try {
        const metrics = await klaviyoClient.get('/metrics/', params);
        return {
          content: [{ type: "text", text: JSON.stringify(metrics, null, 2) }]
        };
      } catch (error) {
        return {
          content: [{ type: "text", text: `Error retrieving metrics: ${error.message}` }],
          isError: true
        };
      }
    },
    { description: "Get metrics from Klaviyo" }
  );

• src/server.js:36-36 (registration)

  Invocation of registerMetricTools which registers the 'get_metrics' tool (among others) on the main MCP server instance.

  registerMetricTools(server);