Mailchimp MCP Server

Instructions

Implementation Reference

• mcp_mailchimp/server.py:513-544 (handler)

  The `add_or_update_member` tool handler is implemented in `mcp_mailchimp/server.py` using `@mcp.tool()` to expose it to the MCP protocol. It performs an upsert operation on a Mailchimp list member using the Mailchimp API.

  @mcp.tool()
  async def add_or_update_member(
      list_id: str,
      email: str,
      status: str = "subscribed",
      first_name: str = "",
      last_name: str = "",
      tags: str = "",
  ) -> str:
      """Add a new subscriber or update if exists (upsert). Status: subscribed, pending, unsubscribed. Tags: comma-separated."""
      mc = get_client()
      h = mc.subscriber_hash(email)
      body: dict[str, Any] = {
          "email_address": email.lower().strip(),
          "status_if_new": status,
      }
      merge_fields: dict[str, str] = {}
      if first_name:
          merge_fields["FNAME"] = first_name
      if last_name:
          merge_fields["LNAME"] = last_name
      if merge_fields:
          body["merge_fields"] = merge_fields
      if tags:
          body["tags"] = [t.strip() for t in tags.split(",") if t.strip()]
      m = await mc.put(f"/lists/{list_id}/members/{h}", json=body)
      return _fmt({
          "email": m.get("email_address", ""),
          "status": m.get("status", ""),
          "id": m.get("id", ""),
          "message": "Member added/updated.",
      })