Klaviyo MCP Server

Implementation Reference

• src/tools/profiles.js:100-148 (registration)

  Registration of the 'update_profile' MCP tool, including inline schema, handler function, and description.

  server.tool(
    "update_profile",
    {
      id: z.string().describe("ID of the profile to update"),
      email: z.string().email().optional().describe("Email address of the profile"),
      phone_number: z.string().optional().describe("Phone number of the profile"),
      external_id: z.string().optional().describe("External ID for the profile"),
      first_name: z.string().optional().describe("First name of the profile"),
      last_name: z.string().optional().describe("Last name of the profile"),
      properties: z.record(z.any()).optional().describe("Additional properties for the profile")
    },
    async (params) => {
      try {
        const { id, ...rest } = params;
        const attributes = {};
        
        // Add all provided fields to attributes
        for (const [key, value] of Object.entries(rest)) {
          if (value !== undefined && key !== 'properties') {
            attributes[key] = value;
          }
        }
        
        // Add properties if provided
        if (params.properties) {
          attributes.properties = params.properties;
        }
        
        const payload = {
          data: {
            type: "profile",
            id,
            attributes
          }
        };
        
        const result = await klaviyoClient.patch(`/profiles/${id}/`, payload);
        return {
          content: [{ type: "text", text: JSON.stringify(result, null, 2) }]
        };
      } catch (error) {
        return {
          content: [{ type: "text", text: `Error updating profile: ${error.message}` }],
          isError: true
        };
      }
    },
    { description: "Update an existing profile in Klaviyo" }
  );

• src/tools/profiles.js:111-147 (handler)

  The handler function that destructures parameters, builds the JSON:API payload for profile update, calls klaviyoClient.patch, and returns the result or error response.

  async (params) => {
    try {
      const { id, ...rest } = params;
      const attributes = {};
      
      // Add all provided fields to attributes
      for (const [key, value] of Object.entries(rest)) {
        if (value !== undefined && key !== 'properties') {
          attributes[key] = value;
        }
      }
      
      // Add properties if provided
      if (params.properties) {
        attributes.properties = params.properties;
      }
      
      const payload = {
        data: {
          type: "profile",
          id,
          attributes
        }
      };
      
      const result = await klaviyoClient.patch(`/profiles/${id}/`, payload);
      return {
        content: [{ type: "text", text: JSON.stringify(result, null, 2) }]
      };
    } catch (error) {
      return {
        content: [{ type: "text", text: `Error updating profile: ${error.message}` }],
        isError: true
      };
    }
  },
  { description: "Update an existing profile in Klaviyo" }

• src/tools/profiles.js:102-110 (schema)

  Zod validation schema defining the input parameters for the 'update_profile' tool.

  {
    id: z.string().describe("ID of the profile to update"),
    email: z.string().email().optional().describe("Email address of the profile"),
    phone_number: z.string().optional().describe("Phone number of the profile"),
    external_id: z.string().optional().describe("External ID for the profile"),
    first_name: z.string().optional().describe("First name of the profile"),
    last_name: z.string().optional().describe("Last name of the profile"),
    properties: z.record(z.any()).optional().describe("Additional properties for the profile")
  },

• src/klaviyo-client.js:192-200 (helper)

  The patch helper function used by the update_profile handler to make the HTTP PATCH request to Klaviyo API with retry logic.

  export async function patch(endpoint, data, fallbackFn) {
    return executeWithRetry(
      () => client.patch(endpoint, data),
      'PATCH',
      endpoint,
      data,
      fallbackFn
    );
  }