Reddit Buddy MCP

Instructions

Implementation Reference

• src/tools/index.ts:123-206 (handler)

  The main handler function implementing the search_reddit tool logic: performs Reddit search via API, handles multiple subreddits, applies filters for author and flair, extracts and formats post data.

  async searchReddit(params: z.infer<typeof searchRedditSchema>) {
    // Handle multiple subreddits
    let results: RedditListing<RedditPost>;
    
    if (params.subreddits && params.subreddits.length > 0) {
      if (params.subreddits.length === 1) {
        // Single subreddit - direct search
        results = await this.api.search(params.query, {
          subreddit: params.subreddits[0],
          sort: params.sort,
          time: params.time,
          limit: params.limit,
        });
      } else {
        // Multiple subreddits - parallel search
        const searchPromises = params.subreddits.map(sub => 
          this.api.search(params.query, {
            subreddit: sub,
            sort: params.sort,
            time: params.time,
            limit: Math.ceil(params.limit! / params.subreddits!.length),
          })
        );
        
        const allResults = await Promise.all(searchPromises);
        
        // Combine results
        results = {
          kind: 'Listing',
          data: {
            children: allResults.flatMap(r => r.data.children),
            after: null,
            before: null,
          }
        };
      }
    } else {
      // Search all of Reddit
      results = await this.api.search(params.query, {
        subreddit: undefined,
        sort: params.sort,
        time: params.time,
        limit: params.limit,
      });
    }
  
    // Filter by author if specified
    if (params.author) {
      results.data.children = results.data.children.filter(
        child => child.data.author.toLowerCase() === params.author!.toLowerCase()
      );
    }
  
    // Filter by flair if specified
    if (params.flair) {
      results.data.children = results.data.children.filter(
        child => child.data.link_flair_text?.toLowerCase().includes(params.flair!.toLowerCase())
      );
    }
  
    // Extract just the essential fields from Reddit's verbose response
    const posts = results.data.children.map(child => ({
      id: child.data.id,
      title: child.data.title,
      author: child.data.author,
      score: child.data.score,
      upvote_ratio: child.data.upvote_ratio,
      num_comments: child.data.num_comments,
      created_utc: child.data.created_utc,
      url: child.data.url,
      permalink: `https://reddit.com${child.data.permalink}`,
      subreddit: child.data.subreddit,
      is_video: child.data.is_video,
      is_text_post: child.data.is_self,
      content: child.data.selftext?.substring(0, 500), // Limit text preview
      nsfw: child.data.over_18,
      link_flair_text: child.data.link_flair_text,
    }));
  
    return {
      results: posts,
      total_results: posts.length
    };
  }

• src/tools/index.ts:20-28 (schema)

  Zod schema defining the input parameters and validation for the search_reddit tool.

  export const searchRedditSchema = z.object({
    query: z.string().describe('Search query'),
    subreddits: z.array(z.string()).optional().describe('Subreddits to search in (leave empty for all)'),
    sort: z.enum(['relevance', 'hot', 'top', 'new', 'comments']).optional().default('relevance'),
    time: z.enum(['hour', 'day', 'week', 'month', 'year', 'all']).optional().default('all'),
    limit: z.number().min(1).max(100).optional().default(25).describe('Default 25, range (1-100). Override ONLY IF user requests.'),
    author: z.string().optional(),
    flair: z.string().optional(),
  });

• src/mcp-server.ts:113-116 (registration)

  Registration of the search_reddit tool in the MCP server toolDefinitions array, specifying name, description, and input schema.

  name: 'search_reddit',
  description: 'Search for posts across Reddit or specific subreddits. Returns matching posts with content and metadata.',
  inputSchema: zodToJsonSchema(searchRedditSchema) as any,
  readOnlyHint: true

• src/mcp-server.ts:156-159 (registration)

  Dispatch case in the tools/call handler that routes search_reddit calls to the searchReddit method.

  case 'search_reddit':
    result = await tools.searchReddit(
      searchRedditSchema.parse(args)
    );