Bluesky MCP Server

Instructions

Implementation Reference

• src/index.ts:946-1055 (handler)

  Complete registration and implementation of the 'get-list-posts' tool. This includes the tool name, description, Zod input schema for list URI, count, and type parameters, and the full async handler function that validates the list URI, fetches posts via Bluesky's getListFeed API with pagination support, applies optional time-based filtering, limits results, preprocesses the posts using preprocessPosts, formats a summary, and returns a formatted response or error.

  server.tool(
    "get-list-posts",
    "Fetch posts from users in a specified list",
    {
      list: z.string().describe("The URI of the list (e.g., at://did:plc:abcdef/app.bsky.graph.list/listname)"),
      count: z.number().min(1).max(500).describe("Number of posts to fetch or hours to look back"),
      type: z.enum(["posts", "hours"]).describe("Whether count represents number of posts or hours to look back")
    },
    async ({ list, count, type }) => {
      if (!agent) {
        return mcpErrorResponse("Not connected to Bluesky. Check your environment variables.");
      }
  
      const currentAgent = agent; // Assign to non-null variable to satisfy TypeScript
      
      try {
        // Validate the list by getting its info
        const listInfo = await validateUri(currentAgent, list, 'list');
        if (!listInfo) {
          return mcpErrorResponse(`Invalid list URI or list not found: ${list}.`);
        }
  
        const MAX_TOTAL_POSTS = 500; // Safety limit to prevent excessive API calls
        
        let allPosts: any[] = [];
        let nextCursor: string | undefined = undefined;
        let shouldContinueFetching = true;
        
        // Set up time-based or count-based fetching
        const useHoursLimit = type === "hours";
        const targetHours = count;
        const targetDate = new Date(Date.now() - targetHours * 60 * 60 * 1000);
        
        while (shouldContinueFetching && allPosts.length < MAX_TOTAL_POSTS) {
          // Calculate how many posts to fetch in this batch
          const batchLimit = 100;
          
          const response = await currentAgent.app.bsky.feed.getListFeed({ 
            list,
            limit: batchLimit,
            cursor: nextCursor
          });
          
          if (!response.success) {
            break;
          }
          
          const { feed, cursor } = response.data;
          
          // Filter posts based on time window if using hours limit
          let filteredFeed = feed;
          if (useHoursLimit) {
            filteredFeed = feed.filter(post => {
              const createdAt = post?.post?.record?.createdAt;
              if (!createdAt || typeof createdAt !== 'string') return false;
              const postDate = new Date(createdAt);
              return postDate >= targetDate;
            });
          }
          
          // Add the filtered posts to our collection
          allPosts = allPosts.concat(filteredFeed);
          
          // Update cursor for the next batch
          nextCursor = cursor;
          
          // Check if we should continue fetching based on the mode
          if (useHoursLimit) {
            // Check if we've reached posts older than our target date
            const oldestPost = feed[feed.length - 1];
            if (oldestPost?.post?.record?.createdAt && typeof oldestPost.post.record.createdAt === 'string') {
              const postDate = new Date(oldestPost.post.record.createdAt);
              if (postDate < targetDate) {
                shouldContinueFetching = false;
              }
            }
          } else {
            // If we're using count-based fetching, stop when we have enough posts
            shouldContinueFetching = allPosts.length < count;
          }
          
          // Stop if we don't have a cursor for the next page
          if (!cursor) {
            shouldContinueFetching = false;
          }
        }
        
        // If we're using count-based fetching, limit the posts to the requested count
        const finalPosts = !useHoursLimit
          ? allPosts.slice(0, count)
          : allPosts;
  
        // If no posts were found after filtering
        if (finalPosts.length === 0) {
          return mcpSuccessResponse(`No posts found from the list.`);
        }
  
        // Format the posts
        const formattedPosts = preprocessPosts(finalPosts);
  
        // Add summary information
        const summaryText = formatSummaryText(finalPosts.length, "list");
  
        return mcpSuccessResponse(`${summaryText}\n\n${formattedPosts}`);
      } catch (error) {
        return mcpErrorResponse(`Error fetching list posts: ${error instanceof Error ? error.message : String(error)}`);
      }
    }
  );