YouTube Transcript DL MCP Server

import express, { Request, Response, NextFunction } from 'express'; import cors from 'cors'; import helmet from 'helmet'; import rateLimit from 'express-rate-limit'; import { BaseTransport } from './base-transport.js'; import { Server } from '@modelcontextprotocol/sdk/server/index.js'; import http from 'http'; export class SimpleHTTPTransport extends BaseTransport { private app?: express.Application; private httpServer?: http.Server; async start(): Promise<void> { if (!this.options.enabled) { this.logger.info('HTTP transport is disabled'); return; } try { this.app = express(); // Security middleware this.app.use(helmet()); // Enable CORS this.app.use(cors({ origin: true, credentials: true, methods: ['GET', 'POST', 'OPTIONS'] })); // JSON body parser this.app.use(express.json({ limit: '10mb' })); // Rate limiting const limiter = rateLimit({ windowMs: 15 * 60 * 1000, // 15 minutes max: 100 // limit each IP to 100 requests per windowMs }); this.app.use('/rpc', limiter); // Setup RPC endpoint that manually handles MCP messages this.app.post('/rpc', async (req: Request, res: Response) => { try { const { jsonrpc, id, method, params } = req.body; if (jsonrpc !== '2.0') { return res.status(400).json({ jsonrpc: '2.0', id, error: { code: -32600, message: 'Invalid Request' } }); } // Handle MCP methods directly let result; switch (method) { case 'tools/list': result = await this.handleToolsList(); break; case 'tools/call': result = await this.handleToolCall(params); break; default: return res.status(400).json({ jsonrpc: '2.0', id, error: { code: -32601, message: 'Method not found' } }); } return res.json({ jsonrpc: '2.0', id, result }); } catch (error) { this.logger.error('RPC error:', error); return res.status(500).json({ jsonrpc: '2.0', id: req.body.id, error: { code: -32603, message: 'Internal error', data: error instanceof Error ? error.message : 'Unknown error' } }); } }); // Health check endpoint this.app.get('/health', (req: Request, res: Response) => { res.json({ status: 'healthy', transport: 'http', timestamp: new Date().toISOString() }); }); // Root endpoint this.app.get('/', (req: Request, res: Response) => { res.json({ name: 'YouTube Transcript MCP Server (HTTP)', version: '1.0.0', transport: 'http', endpoint: '/rpc', health: '/health' }); }); // Error handling middleware this.app.use((err: Error, req: Request, res: Response, next: NextFunction) => { this.logger.error('HTTP transport error:', err); res.status(500).json({ error: 'Internal server error', message: err.message }); }); // Start HTTP server const port = this.options.port || 3002; const host = this.options.host || '0.0.0.0'; this.httpServer = this.app.listen(port, host, () => { this.logger.info(`HTTP transport listening on ${host}:${port}`); }); this.isRunning = true; this.logger.info(`HTTP transport started successfully on port ${port}`); } catch (error) { this.logger.error('Failed to start HTTP transport:', error); throw error; } } private async handleToolsList() { // Mock tools list - in a real implementation, this would come from the MCP server return { tools: [ { name: 'get_transcript', description: 'Extract transcript from a single YouTube video', inputSchema: { type: 'object', properties: { videoId: { type: 'string', description: 'YouTube video ID or URL' }, language: { type: 'string', description: 'Language code', default: 'en' }, format: { type: 'string', enum: ['text', 'json', 'srt'], default: 'json' } }, required: ['videoId'] } }, { name: 'get_bulk_transcripts', description: 'Extract transcripts from multiple YouTube videos', inputSchema: { type: 'object', properties: { videoIds: { type: 'array', items: { type: 'string' } }, language: { type: 'string', default: 'en' }, outputFormat: { type: 'string', enum: ['text', 'json', 'srt'], default: 'json' } }, required: ['videoIds'] } } ] }; } private async handleToolCall(params: any) { const { name, arguments: args } = params; // Mock tool execution - in a real implementation, this would delegate to the MCP server switch (name) { case 'get_transcript': return { content: [{ type: 'text', text: JSON.stringify({ videoId: args.videoId, message: 'HTTP transport is working! (Mock response)', timestamp: new Date().toISOString() }, null, 2) }] }; case 'get_bulk_transcripts': return { content: [{ type: 'text', text: JSON.stringify({ results: args.videoIds.map((id: string) => ({ videoId: id, message: 'HTTP transport bulk processing! (Mock response)' })), timestamp: new Date().toISOString() }, null, 2) }] }; default: throw new Error(`Unknown tool: ${name}`); } } async stop(): Promise<void> { if (!this.isRunning) return; try { if (this.httpServer) { await new Promise<void>((resolve, reject) => { this.httpServer!.close((err) => { if (err) reject(err); else resolve(); }); }); } this.isRunning = false; this.logger.info('HTTP transport stopped'); } catch (error) { this.logger.error('Error stopping HTTP transport:', error); throw error; } } }