Reddit Buddy MCP

/** * Proper MCP Server implementation with stdio and streamable HTTP transports */ import { Server } from '@modelcontextprotocol/sdk/server/index.js'; import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js'; import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js'; import { CallToolRequestSchema, ListToolsRequestSchema, Tool } from '@modelcontextprotocol/sdk/types.js'; import { createServer, IncomingMessage, ServerResponse } from 'http'; import { zodToJsonSchema } from 'zod-to-json-schema'; import { AuthManager } from './core/auth.js'; import { CacheManager } from './core/cache.js'; import { RateLimiter } from './core/rate-limiter.js'; import { RedditAPI } from './services/reddit-api.js'; import { RedditTools, browseSubredditSchema, searchRedditSchema, getPostDetailsSchema, userAnalysisSchema, redditExplainSchema, } from './tools/index.js'; // Server metadata export const SERVER_NAME = 'reddit-mcp-buddy'; export const SERVER_VERSION = '1.1.10'; /** * Create MCP server with proper protocol implementation */ export async function createMCPServer() { // Initialize core components const authManager = new AuthManager(); await authManager.load(); const rateLimit = authManager.getRateLimit(); const cacheTTL = authManager.getCacheTTL(); const disableCache = process.env.REDDIT_BUDDY_NO_CACHE === 'true'; console.error(`🚀 Reddit MCP Buddy Server v${SERVER_VERSION}`); console.error(`📊 Mode: ${authManager.getAuthMode()}`); console.error(`⏱️ Rate limit: ${rateLimit} requests/minute`); console.error(`💾 Cache: ${disableCache ? 'Disabled' : `TTL ${cacheTTL / 60000} minutes`}`); // Create cache manager with auth-based TTL const cacheManager = new CacheManager({ defaultTTL: disableCache ? 0 : cacheTTL, maxSize: disableCache ? 0 : 50 * 1024 * 1024, // 50MB or 0 if disabled }); // Create rate limiter const rateLimiter = new RateLimiter({ limit: rateLimit, window: 60000, // 1 minute name: 'Reddit API', }); // Create Reddit API client const redditAPI = new RedditAPI({ authManager, rateLimiter, cacheManager, }); // Create tools instance const tools = new RedditTools(redditAPI); // Create MCP server const server = new Server( { name: SERVER_NAME, version: SERVER_VERSION, description: `Reddit content browser and analyzer. Access posts, comments, and user data from Reddit. KEY CONCEPTS: - Subreddits: Communities like "technology", "science". Use without r/ prefix - Special subreddits: "all" (entire Reddit), "popular" (trending/default) - Sorting: "hot" (trending), "new" (recent), "top" (highest score), "rising" (gaining traction), "controversial" (disputed) - Time ranges: For "top" sort - "hour", "day", "week", "month", "year", "all" - Post IDs: Short codes like "abc123" from Reddit URLs - Usernames: Without u/ prefix (use "spez" not "u/spez") COMMON QUERIES: - "What's trending on Reddit?" → browse_subreddit with subreddit="all" and sort="hot" - "Top posts this week in technology" → browse_subreddit with subreddit="technology", sort="top", time="week" - "Search for AI discussions" → search_reddit with query="artificial intelligence" - "Get comments on a Reddit post" → get_post_details with URL or just post_id - "Analyze a Reddit user" → user_analysis with username Rate limits: ${rateLimit} requests/minute. Cache TTL: ${cacheTTL / 60000} minutes.`, }, { capabilities: { tools: {}, }, } ); // Generate tool definitions from Zod schemas const toolDefinitions: Tool[] = [ { name: 'browse_subreddit', description: 'Fetch posts from a subreddit sorted by your choice (hot/new/top/rising). Returns post list with content, scores, and metadata.', inputSchema: zodToJsonSchema(browseSubredditSchema) as any, readOnlyHint: true }, { 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 }, { name: 'get_post_details', description: 'Fetch a Reddit post with its comments. Requires EITHER url OR post_id. IMPORTANT: When using post_id alone, an extra API call is made to fetch the subreddit first (2 calls total). For better efficiency, always provide the subreddit parameter when known (1 call total).', inputSchema: zodToJsonSchema(getPostDetailsSchema) as any, readOnlyHint: true }, { name: 'user_analysis', description: 'Analyze a Reddit user\'s posting history, karma, and activity patterns. Returns posts, comments, and statistics.', inputSchema: zodToJsonSchema(userAnalysisSchema) as any, readOnlyHint: true }, { name: 'reddit_explain', description: 'Get explanations of Reddit terms, slang, and culture. Returns definition, origin, usage, and examples.', inputSchema: zodToJsonSchema(redditExplainSchema) as any, readOnlyHint: true } ]; // Store handlers for HTTP access const handlers = { 'tools/list': async () => ({ tools: toolDefinitions, }), 'tools/call': async (params: any) => { const { name, arguments: args } = params; try { let result: any; // Validate and parse arguments based on tool switch (name) { case 'browse_subreddit': result = await tools.browseSubreddit( browseSubredditSchema.parse(args) ); break; case 'search_reddit': result = await tools.searchReddit( searchRedditSchema.parse(args) ); break; case 'get_post_details': result = await tools.getPostDetails( getPostDetailsSchema.parse(args) ); break; case 'user_analysis': result = await tools.userAnalysis( userAnalysisSchema.parse(args) ); break; case 'reddit_explain': result = await tools.redditExplain( redditExplainSchema.parse(args) ); break; default: throw new Error(`Unknown tool: ${name}`); } return { content: [ { type: 'text', text: JSON.stringify(result, null, 2), }, ], }; } catch (error: any) { return { content: [ { type: 'text', text: `Error: ${error.message}`, }, ], isError: true, }; } } }; // Register handlers with the MCP server server.setRequestHandler(ListToolsRequestSchema, handlers['tools/list']); server.setRequestHandler(CallToolRequestSchema, async (request) => { return handlers['tools/call'](request.params); }); return { server, cacheManager, tools, handlers }; } /** * Start server with stdio transport (for Claude Desktop) */ export async function startStdioServer() { const { server, cacheManager } = await createMCPServer(); const transport = new StdioServerTransport(); await server.connect(transport); console.error('✅ Reddit MCP Buddy Server running (stdio mode)'); console.error('💡 Reading from stdin, writing to stdout'); // Cleanup on exit process.on('SIGINT', () => { cacheManager.destroy(); process.exit(0); }); process.on('SIGTERM', () => { cacheManager.destroy(); process.exit(0); }); } /** * Start server with streamable HTTP transport for Postman MCP */ export async function startHttpServer(port: number = 3000) { const { server, cacheManager } = await createMCPServer(); // Create transport - stateless mode for simpler setup const transport = new StreamableHTTPServerTransport({ sessionIdGenerator: undefined, // Stateless mode - no session management enableJsonResponse: false // Use SSE for notifications }); // Connect MCP server to transport await server.connect(transport); // Create HTTP server const httpServer = createServer(async (req: IncomingMessage, res: ServerResponse) => { // Enable CORS res.setHeader('Access-Control-Allow-Origin', '*'); res.setHeader('Access-Control-Allow-Methods', 'GET, POST, DELETE, OPTIONS'); res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Accept, MCP-Session-Id'); res.setHeader('Access-Control-Expose-Headers', 'MCP-Session-Id'); // Handle OPTIONS for CORS preflight if (req.method === 'OPTIONS') { res.writeHead(200); res.end(); return; } // Handle health check if (req.url === '/health' && req.method === 'GET') { res.writeHead(200, { 'Content-Type': 'application/json' }); res.end(JSON.stringify({ status: 'ok', server: SERVER_NAME, version: SERVER_VERSION, protocol: 'MCP', transport: 'streamable-http', features: { sessions: true, notifications: true, resumability: false } })); return; } // Handle root endpoint if (req.url === '/' && req.method === 'GET') { res.writeHead(200, { 'Content-Type': 'text/plain' }); res.end('Reddit MCP Buddy Server (Streamable HTTP)\n'); return; } // Handle MCP endpoint - delegate to transport if (req.url === '/mcp') { // Parse body for POST requests if (req.method === 'POST') { let body = ''; req.on('data', chunk => { body += chunk.toString(); }); req.on('end', async () => { try { const parsedBody = JSON.parse(body); await transport.handleRequest(req, res, parsedBody); } catch (error) { res.writeHead(400, { 'Content-Type': 'application/json' }); res.end(JSON.stringify({ jsonrpc: '2.0', error: { code: -32700, message: 'Parse error' }, id: null })); } }); } else { // GET or DELETE requests await transport.handleRequest(req, res); } return; } // 404 for other endpoints res.writeHead(404, { 'Content-Type': 'text/plain' }); res.end('Not Found\n'); }); // Start listening httpServer.listen(port, () => { console.error(`✅ Reddit MCP Buddy Server running (Streamable HTTP)`); console.error(`🌐 Base URL: http://localhost:${port}`); console.error(`📡 MCP endpoint: http://localhost:${port}/mcp`); console.error(`🔌 Connect with Postman MCP client`); console.error('💡 Tip: Run "reddit-mcp-buddy --auth" for 10x more requests\n'); }); // Cleanup on exit const cleanup = () => { cacheManager.destroy(); httpServer.close(); process.exit(0); }; process.on('SIGINT', cleanup); process.on('SIGTERM', cleanup); }