Hacker News MCP Server

Instructions

Implementation Reference

• src/index.ts:465-489 (handler)

  Main handler for the 'getUser' tool: validates input using UserRequestSchema, fetches user data via hnApi.getUser, formats it with formatUser, constructs response text with user profile details.

  case "getUser": {
    const validatedArgs = validateInput(UserRequestSchema, args);
    const { id } = validatedArgs;
  
    const user = await hnApi.getUser(id);
  
    if (!user) {
      throw new McpError(
        ErrorCode.InvalidParams,
        `User with ID ${id} not found`
      );
    }
  
    const formattedUser = formatUser(user);
    const text =
      `User Profile:\n` +
      `Username: ${formattedUser.id}\n` +
      `Karma: ${formattedUser.karma}\n` +
      `Created: ${new Date(formattedUser.created * 1000).toISOString()}\n` +
      (formattedUser.about ? `\nAbout:\n${formattedUser.about}\n` : "");
  
    return {
      content: [{ type: "text", text: text.trim() }],
    };
  }

• src/index.ts:150-160 (registration)

  Registers the 'getUser' tool in the ListTools response, specifying name, description, and input schema.

  {
    name: "getUser",
    description: "Get a user profile by ID",
    inputSchema: {
      type: "object",
      properties: {
        id: { type: "string", description: "The ID of the user" },
      },
      required: ["id"],
    },
  },

• src/schemas/index.ts:62-64 (schema)

  Zod schema for validating the input parameters of the 'getUser' tool (user ID as string).

  export const UserRequestSchema = z.object({
    id: z.string(),
  });

• src/api/hn.ts:81-84 (helper)

  HackerNewsAPI method that fetches user profile data from the official HN Firebase API endpoint.

  async getUser(id: string): Promise<any> {
    const response = await fetch(`${API_BASE_URL}/user/${id}.json`);
    return response.json();
  }

• src/models/user.ts:9-17 (helper)

  Helper function to format raw user data from HN API into a structured User interface.

  export function formatUser(user: any): User {
    return {
      id: user.id,
      created: user.created,
      karma: user.karma,
      about: user.about,
      submitted: user.submitted,
    };
  }