mailchimp-mcp

Instructions

Implementation Reference

• server.js:159-216 (handler)

  The set_campaign_content tool is registered and implemented in server.js, handling input validation for campaign content and interaction with the Mailchimp campaigns API.

  server.tool(
    "set_campaign_content",
    "Set the HTML/plain-text content for a campaign. Provide either html for custom content or template_id to use a Mailchimp template.",
    {
      campaign_id: z.string().describe("Campaign ID"),
      html: z.string().optional().describe("Full HTML content for the email"),
      plain_text: z.string().optional().describe("Plain text version of the email"),
      template_id: z.number().optional().describe("Mailchimp template ID to use instead of raw HTML"),
    },
    async ({ campaign_id, html, plain_text, template_id }) => {
      if (!html && !template_id) {
        return {
          content: [{ type: "text", text: JSON.stringify({ error: "Must provide either 'html' or 'template_id'" }, null, 2) }],
          isError: true,
        };
      }
      const body = {};
      if (html && template_id) {
        // html and template_id are mutually exclusive in Mailchimp API.
        // When both are sent, Mailchimp silently ignores html and uses the template.
        // Prefer html (the explicit content) and warn.
        body.html = html;
        if (plain_text) body.plain_text = plain_text;
        const response = await mailchimp.campaigns.setContent(campaign_id, body);
        return {
          content: [
            {
              type: "text",
              text: JSON.stringify({
                success: true,
                warning: "Both html and template_id were provided. Used html only — Mailchimp ignores html when template is also set.",
                has_html: !!response.html,
                has_plain_text: !!response.plain_text,
              }, null, 2),
            },
          ],
        };
      }
      if (template_id) {
        body.template = { id: template_id };
      }
      if (html) {
        body.html = html;
      }
      if (plain_text) {
        body.plain_text = plain_text;
      }
      const response = await mailchimp.campaigns.setContent(campaign_id, body);
      return {
        content: [
          {
            type: "text",
            text: JSON.stringify({ success: true, has_html: !!response.html, has_plain_text: !!response.plain_text }, null, 2),
          },
        ],
      };
    }
  );