substack-mcp

Instructions

Implementation Reference

• src/server.ts:110-140 (handler)

  The 'get_draft' tool registration with its handler function. Uses Zod schema to validate draft_id parameter, calls client.getDraft(), and returns the draft data (id, title, subtitle, body, audience, word_count, created_at, updated_at) as JSON.

  server.tool(
    "get_draft",
    "Get the full content of a draft post by ID. Returns title, body, metadata.",
    {
      draft_id: z.number().describe("The draft ID to retrieve"),
    },
    async ({ draft_id }) => {
      const draft = await client.getDraft(draft_id);
      return {
        content: [
          {
            type: "text",
            text: JSON.stringify(
              {
                id: draft.id,
                title: draft.draft_title,
                subtitle: draft.draft_subtitle,
                body: draft.draft_body,
                audience: draft.audience,
                word_count: draft.word_count,
                created_at: draft.draft_created_at,
                updated_at: draft.draft_updated_at,
              },
              null,
              2,
            ),
          },
        ],
      };
    },
  );

• src/api/client.ts:111-115 (helper)

  The getDraft method in SubstackClient that makes the actual HTTP GET request to the Substack API endpoint /api/v1/drafts/{id} to fetch a single draft by ID.

  async getDraft(id: number): Promise<SubstackDraft> {
    return this.request<SubstackDraft>(
      `${this.publicationUrl}/api/v1/drafts/${id}`,
    );
  }

• src/api/types.ts:38-51 (schema)

  The SubstackDraft interface defining the structure of draft data returned by the get_draft tool, including id, draft_title, draft_subtitle, draft_body, audience, word_count, and timestamps.

  export interface SubstackDraft {
    id: number;
    draft_title: string;
    draft_subtitle: string | null;
    draft_body: string | null;
    draft_bylines: Array<{ id: number; is_guest: boolean }>;
    audience: string;
    type: string;
    word_count: number;
    cover_image: string | null;
    section_id: number | null;
    draft_created_at: string;
    draft_updated_at: string;
  }