Reddit MCP Tool

Instructions

Implementation Reference

• reddit_mcp/server.py:181-233 (handler)

  The main tool handler function for 'get_reddit_post_details', decorated with @mcp.tool() which registers it in FastMCP. It handles input validation implicitly via type hints, fetches data using the RedditClient helper, formats the output as a human-readable string, provides initialization error messages, and error handling.

  @mcp.tool()
  async def get_reddit_post_details(post_id: str) -> str:
      """
      Get detailed information about a specific Reddit post
  
      Args:
          post_id: The Reddit post ID
  
      Returns:
          Human readable string containing detailed post information
      """
      if reddit_client is None:
          return """Error: Reddit client not initialized. 
  
  To fix this:
  1. Copy env.example to .env: cp env.example .env
  2. Edit .env with your Reddit API credentials:
     - Get credentials from https://old.reddit.com/prefs/apps/
     - Create a 'script' type app
     - Fill in REDDIT_CLIENT_ID, REDDIT_CLIENT_SECRET, and REDDIT_USER_AGENT
  3. Restart the MCP server
  
  Example .env content:
  REDDIT_CLIENT_ID=your_14_char_client_id
  REDDIT_CLIENT_SECRET=your_27_char_client_secret  
  REDDIT_USER_AGENT=reddit-mcp-tool:v0.2.0 (by /u/yourusername)"""
      
      try:
          post_details = await reddit_client.get_post_details(post_id)
          
          result = (
              f"**{post_details['title']}**\n\n"
              f"Author: {post_details['author']}\n"
              f"Score: {post_details['score']} (upvote ratio: {post_details['upvote_ratio']:.0%})\n"
              f"Comments: {post_details['num_comments']}\n"
              f"Link: {post_details['permalink']}\n"
              f"Subreddit: r/{post_details['subreddit']}\n"
              f"Domain: {post_details['domain']}\n"
              f"Locked: {post_details['locked']}\n"
              f"Stickied: {post_details['stickied']}\n"
          )
          
          if post_details.get('flair_text'):
              result += f"Flair: {post_details['flair_text']}\n"
          
          if post_details['selftext']:
              result += f"\nContent:\n{post_details['selftext']}\n"
          
          return result
          
      except Exception as e:
          logger.error(f"Error getting post details for {post_id}: {str(e)}")
          return f"Error getting post details for {post_id}: {str(e)}"

• reddit_mcp/reddit_client.py:73-98 (helper)

  The RedditClient.get_post_details method, a supporting utility that uses asyncpraw to fetch detailed post data from the Reddit API and returns a structured dictionary used by the tool handler.

  async def get_post_details(self, post_id: str) -> Dict[str, Any]:
      """Get detailed information about a specific post."""
      try:
          submission = await self.reddit.submission(id=post_id)
          
          return {
              "id": submission.id,
              "title": submission.title,
              "author": str(submission.author) if submission.author else "[deleted]",
              "score": submission.score,
              "upvote_ratio": submission.upvote_ratio,
              "url": submission.url,
              "permalink": f"https://reddit.com{submission.permalink}",
              "created_utc": submission.created_utc,
              "num_comments": submission.num_comments,
              "selftext": submission.selftext,
              "is_self": submission.is_self,
              "domain": submission.domain,
              "subreddit": str(submission.subreddit),
              "flair_text": submission.link_flair_text,
              "locked": submission.locked,
              "stickied": submission.stickied,
          }
          
      except Exception as e:
          raise Exception(f"Error getting post details for {post_id}: {str(e)}")