MCP Time Server Node

#!/usr/bin/env -S npx tsx /** * Research MCP SDK types for proper error handling */ import type { JSONRPCError, JSONRPCRequest, JSONRPCResponse, CallToolResult, } from '@modelcontextprotocol/sdk/types.js'; console.log('=== MCP SDK Type Research ===\n'); // Explore error codes console.log('1. Standard JSON-RPC Error Codes:'); console.log(' -32700: Parse error'); console.log(' -32600: Invalid Request'); console.log(' -32601: Method not found'); console.log(' -32602: Invalid params'); console.log(' -32603: Internal error'); console.log(' -32000 to -32099: Server error (reserved for implementation-defined errors)\n'); // Check how MCP handles errors console.log('2. MCP Error Handling:'); console.log(' - Errors are returned as JSONRPCError objects'); console.log(' - The CallToolResult can include an error property'); console.log(' - Server can return error responses directly\n'); // Type definitions console.log('3. Type Definitions for Reference:'); console.log(` interface JSONRPCError { code: number; message: string; data?: unknown; } interface ErrorResponse { jsonrpc: "2.0"; id: string | number | null; error: JSONRPCError; } // For tool execution errors interface CallToolResult { content?: Array<{ type: string; text?: string }>; error?: { code: string; message: string; details?: unknown; }; } `); console.log('\n4. Rate Limiting Error Response Options:'); console.log(' Option A: Return JSON-RPC error (blocks at protocol level)'); console.log(' Option B: Return CallToolResult with error (tool-level error)'); console.log(' Option C: Throw error and let handler convert it\n'); console.log('5. Best Practice Recommendation:'); console.log(' - Use JSON-RPC error (-32000 range) for rate limiting'); console.log(' - This prevents tool execution entirely'); console.log(' - Include helpful data in error.data field'); console.log(' - Client gets immediate feedback without tool processing\n'); console.log('=== Research Complete ===');