list_comments

Instructions

Implementation Reference

• src/tools/comments.ts:29-45 (handler)

  The handler function that executes the 'list_comments' tool logic. It calls client.listComments(video_id, max_results) and formats the output.

    async (args) => {
      const data = await client.listComments(args.video_id, args.max_results);
      const lines = [
        `Found ${data.items.length} comment thread(s) on ${args.video_id}:`,
        ...data.items.map((thread) => {
          const top = thread.snippet?.topLevelComment?.snippet;
          const id = thread.snippet?.topLevelComment?.id ?? "?";
          const author = top?.authorDisplayName ?? "?";
          const text = (top?.textOriginal ?? "").replace(/\s+/g, " ").slice(0, 160);
          const likes = top?.likeCount ?? 0;
          const replies = thread.snippet?.totalReplyCount ?? 0;
          return `  ${id} — ${author} (${likes}❤, ${replies}↩): ${text}`;
        }),
      ];
      return { content: [{ type: "text" as const, text: lines.join("\n") }] };
    },
  );

• src/tools/comments.ts:5-8 (schema)

  Input schema for list_comments: video_id (string) and optional max_results (number, 1-100, default 20).

  const listCommentsSchema = {
    video_id: z.string().describe("Video ID to list comments from"),
    max_results: z.number().int().min(1).max(100).default(20),
  };

• src/tools/comments.ts:24-45 (registration)

  The registerCommentTools function that calls server.tool('list_comments', ...) to register the tool with the MCP server.

  export function registerCommentTools(server: McpServer, client: YouTubeClient): void {
    server.tool(
      "list_comments",
      "List top-level comment threads on a video (newest first). Returns comment IDs, authors, text, and like counts.",
      listCommentsSchema,
      async (args) => {
        const data = await client.listComments(args.video_id, args.max_results);
        const lines = [
          `Found ${data.items.length} comment thread(s) on ${args.video_id}:`,
          ...data.items.map((thread) => {
            const top = thread.snippet?.topLevelComment?.snippet;
            const id = thread.snippet?.topLevelComment?.id ?? "?";
            const author = top?.authorDisplayName ?? "?";
            const text = (top?.textOriginal ?? "").replace(/\s+/g, " ").slice(0, 160);
            const likes = top?.likeCount ?? 0;
            const replies = thread.snippet?.totalReplyCount ?? 0;
            return `  ${id} — ${author} (${likes}❤, ${replies}↩): ${text}`;
          }),
        ];
        return { content: [{ type: "text" as const, text: lines.join("\n") }] };
      },
    );

• src/server.ts:49-49 (registration)

  Where registerCommentTools is called from server.ts to wire up the tool.

  registerCommentTools(s, youtube);

• src/youtube/client.ts:206-213 (helper)

  The YouTubeClient.listComments helper method that performs the actual API call to /commentThreads.

  listComments(videoId: string, maxResults = 20): Promise<{ items: CommentThread[] }> {
    return this.dataGet("/commentThreads", {
      part: "snippet,replies",
      videoId,
      maxResults: String(maxResults),
      order: "time",
    });
  }