Tool Filter MCP

#!/usr/bin/env node import { ProxyOrchestrator } from './proxy.js'; import { createMCPServer } from './server.js'; import { formatStartupError } from './utils/error-handler.js'; import { formatCommandDisplay } from './utils/command-formatter.js'; import { formatToolsList } from './utils/tool-list-formatter.js'; import { createUpstreamClient, createStdioUpstreamClient, type WrappedClient } from './client.js'; import { parseCLIArgs, type CLIArgs } from './cli-args.js'; import { createProxyConfig } from './config.js'; async function listToolsMode(args: CLIArgs): Promise<void> { let upstreamClient: WrappedClient | null = null; try { const config = createProxyConfig(args); // Create upstream client based on config mode if (config.mode === 'http') { console.error(`Connecting to upstream MCP at ${config.upstreamUrl}...`); upstreamClient = await createUpstreamClient(config.upstreamUrl, config.headers); } else { const commandDisplay = formatCommandDisplay(config.upstreamCommand, config.upstreamArgs); console.error(`Connecting to upstream MCP via stdio: ${commandDisplay}...`); upstreamClient = await createStdioUpstreamClient(config.upstreamCommand, config.upstreamArgs, config.env); } await upstreamClient.connect() console.error('Fetching tools from upstream...'); const result = await upstreamClient.listTools(); let tools = result.tools; // Apply filtering if deny patterns are provided if (config.denyPatterns.length > 0) { const patterns = config.denyPatterns.map((pattern) => new RegExp(pattern)); tools = tools.filter((tool) => { return !patterns.some((pattern) => pattern.test(tool.name)); }); console.error(`Applied ${config.denyPatterns.length} filter pattern(s)`); } // Output to stdout (not stderr) so it can be piped/redirected const formatted = formatToolsList(tools, args.format || 'table'); // eslint-disable-next-line no-console console.log(formatted); } catch (error) { const errorMessage = formatStartupError(error); console.error(`Error: ${errorMessage}`); process.exit(1); } finally { if (upstreamClient) { upstreamClient.disconnect(); } } } async function main(): Promise<void> { try { const args = parseCLIArgs(); // Handle list-tools mode if (args.listTools) { await listToolsMode(args); return; } const config = createProxyConfig(args); // Create upstream client based on config mode let upstreamClient: WrappedClient; if (config.mode === 'http') { console.error(`Connecting to upstream MCP at ${config.upstreamUrl}...`); upstreamClient = await createUpstreamClient(config.upstreamUrl, config.headers); } else { const commandDisplay = formatCommandDisplay(config.upstreamCommand, config.upstreamArgs); console.error(`Connecting to upstream MCP via stdio: ${commandDisplay}...`); upstreamClient = await createStdioUpstreamClient(config.upstreamCommand, config.upstreamArgs, config.env); } const proxy = new ProxyOrchestrator(config, upstreamClient); try { await proxy.startup(); } catch (error) { upstreamClient.disconnect(); throw error; } const filteredTools = proxy.getCachedTools(); console.error( `Proxy ready. Filtered ${filteredTools.length} tools from upstream.` ); if (config.denyPatterns.length > 0) { console.error(`Deny patterns: ${config.denyPatterns.join(', ')}`); } if (config.mode === 'http' && config.headers && Object.keys(config.headers).length > 0) { console.error(`Custom headers: ${Object.keys(config.headers).join(', ')}`); } const server = await createMCPServer(proxy); console.error('MCP proxy server running on stdio'); console.error('Press Ctrl+C to stop'); process.on('SIGINT', () => { console.error('\nShutting down...'); proxy.shutdown(); void server.close(); process.exit(0); }); process.on('SIGTERM', () => { console.error('\nShutting down...'); proxy.shutdown(); void server.close(); process.exit(0); }); } catch (error) { const errorMessage = formatStartupError(error); console.error(`Error: ${errorMessage}`); process.exit(1); } } void main();