Search HackerNews Posts

Instructions

Implementation Reference

• src/tools/index.ts:25-67 (handler)

  The handler function that executes the 'search_posts' tool logic: constructs SearchParams, invokes hnClient.searchStories, formats results as structured JSON, and handles errors.

    async ({ query, author, minScore, startTime, endTime, limit }) => {
      try {
        const searchParams: SearchParams = {
          query,
          author,
          minScore,
          startTime,
          endTime,
          limit: limit || 20
        };
  
        const posts = await hnClient.searchStories(searchParams);
  
        return {
          content: [{
            type: "text",
            text: JSON.stringify({
              search_params: searchParams,
              result_count: posts.length,
              posts: posts.map(post => ({
                id: post.id,
                title: post.title,
                by: post.by,
                score: post.score,
                time: post.time,
                url: post.url,
                descendants: post.descendants
              }))
            }, null, 2)
          }]
        };
      } catch (error) {
        logger.error("Failed to search posts:", error);
        return {
          content: [{
            type: "text",
            text: `Error searching posts: ${error instanceof Error ? error.message : String(error)}`
          }],
          isError: true
        };
      }
    }
  );

• src/tools/index.ts:13-23 (schema)

  Input schema using Zod for validating tool parameters: query, author, minScore, time ranges, and limit.

  {
    title: "Search HackerNews Posts",
    description: "Search and filter HackerNews posts by keywords, author, score, and date range",
    inputSchema: {
      query: z.string().optional(),
      author: z.string().optional(),
      minScore: z.number().optional(),
      startTime: z.number().optional(),
      endTime: z.number().optional(),
      limit: z.number().min(1).max(100).default(20).optional()
    }

• src/tools/index.ts:12-67 (registration)

  Registers the 'search_posts' tool with the MCP server in setupTools, providing name, schema, and handler.

    "search_posts",
    {
      title: "Search HackerNews Posts",
      description: "Search and filter HackerNews posts by keywords, author, score, and date range",
      inputSchema: {
        query: z.string().optional(),
        author: z.string().optional(),
        minScore: z.number().optional(),
        startTime: z.number().optional(),
        endTime: z.number().optional(),
        limit: z.number().min(1).max(100).default(20).optional()
      }
    },
    async ({ query, author, minScore, startTime, endTime, limit }) => {
      try {
        const searchParams: SearchParams = {
          query,
          author,
          minScore,
          startTime,
          endTime,
          limit: limit || 20
        };
  
        const posts = await hnClient.searchStories(searchParams);
  
        return {
          content: [{
            type: "text",
            text: JSON.stringify({
              search_params: searchParams,
              result_count: posts.length,
              posts: posts.map(post => ({
                id: post.id,
                title: post.title,
                by: post.by,
                score: post.score,
                time: post.time,
                url: post.url,
                descendants: post.descendants
              }))
            }, null, 2)
          }]
        };
      } catch (error) {
        logger.error("Failed to search posts:", error);
        return {
          content: [{
            type: "text",
            text: `Error searching posts: ${error instanceof Error ? error.message : String(error)}`
          }],
          isError: true
        };
      }
    }
  );

• src/api/client.ts:187-200 (helper)

  Supporting method in HackerNewsClient that performs the actual story search: fetches top stories, retrieves items, filters by parameters, and limits results. Called by the tool handler.

  async searchStories(params: SearchParams): Promise<HackerNewsItem[]> {
    const topStories = await this.getTopStories();
    const storyLimit = Math.min(params.limit || 50, 100); // Limit to avoid too many API calls
    
    const stories = await Promise.all(
      topStories.slice(0, storyLimit * 2).map(id => this.getItem(id))
    );
  
    const validStories = stories.filter((story): story is HackerNewsItem => 
      story !== null && story.type === "story"
    );
  
    return this.filterStories(validStories, params).slice(0, storyLimit);
  }