list_merge_fields

Retrieve all merge fields from a specific Mailchimp list to access custom subscriber data for email personalization and segmentation.

Instructions

List all merge fields in a specific list

Input Schema

TableJSON Schema

Name	Required	Description	Default
`list_id`	Yes	The list ID

Implementation Reference

src/services/mailchimp.ts:361-369 (handler)

The core handler function implementing the logic to list merge fields for a given Mailchimp list ID by calling the Mailchimp API with pagination.

async listMergeFields(
  listId: string
): Promise<{ merge_fields: MailchimpMergeField[] }> {
  return await this.makePaginatedRequest(
    `/lists/${listId}/merge-fields`,
    "display_order",
    "ASC"
  );
}

src/tools/index.ts:346-359 (registration)

Registers the 'list_merge_fields' tool in the getToolDefinitions array, including its name, description, and input schema.

{
  name: "list_merge_fields",
  description: "List all merge fields in a specific list",
  inputSchema: {
    type: "object",
    properties: {
      list_id: {
        type: "string",
        description: "The list ID",
      },
    },
    required: ["list_id"],
  },
},

src/types/index.ts:931-966 (schema)

TypeScript interface defining the MailchimpMergeField structure for output data validation and typing.

export interface MailchimpMergeField {
  id: number;
  name: string;
  type:
    | "text"
    | "number"
    | "address"
    | "phone"
    | "date"
    | "url"
    | "imageurl"
    | "radio"
    | "dropdown"
    | "birthday"
    | "zip";
  required: boolean;
  default_value?: string;
  public: boolean;
  display_order: number;
  options?: {
    default_country?: number;
    phone_format?: string;
    date_format?: string;
    choices?: string[];
    size?: number;
  };
  help_text?: string;
  list_id: string;
  _links?: Array<{
    rel: string;
    href: string;
    method: string;
    targetSchema?: string;
    schema?: string;
  }>;
}

src/tools/index.ts:938-958 (handler)

The tool execution handler in handleToolCall that dispatches to the service and formats the merge fields response for the MCP protocol.

case "list_merge_fields":
  const mergeFields = await service.listMergeFields(args.list_id);
  return {
    content: [
      {
        type: "text",
        text: JSON.stringify(
          mergeFields.merge_fields.map((mf) => ({
            id: mf.id,
            name: mf.name,
            type: mf.type,
            required: mf.required,
            public: mf.public,
            display_order: mf.display_order,
          })),
          null,
          2
        ),
      },
    ],
  };

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