MCP Time Server Node

# MCP SDK Adapter This is our internal SDK that wraps the broken MCP SDK and provides proper error handling. ## Why This Exists The MCP SDK has fundamental flaws: - ErrorCode export bug requires `require()` workaround - Only 3 error codes for everything (InvalidParams, InvalidRequest, InternalError) - No meaningful error differentiation possible - Every MCP implementation creates their own workaround ## How to Use ### In Tools ```typescript // NEVER import from @modelcontextprotocol/sdk directly! import { ValidationError, TimezoneError, DateParsingError, // ... other error types } from '../adapters/mcp-sdk'; export function myTool(params: unknown): ToolResult { // Validate input if (!params.timezone) { throw new ValidationError('Missing required field: timezone'); } // Check specific conditions if (!isValidTimezone(params.timezone)) { throw new TimezoneError('Invalid timezone', params.timezone); } // ... tool logic } ``` ### Error Types - `ValidationError` - Invalid input parameters (400) → InvalidParams - `TimezoneError` - Invalid timezone specification (400) → InvalidParams - `DateParsingError` - Cannot parse date/time (400) → InvalidParams - `BusinessHoursError` - Invalid business hours config (400) → InvalidRequest - `HolidayDataError` - Cannot fetch holiday data (503) → InvalidRequest - `TimeCalculationError` - Arithmetic overflow/underflow (500) → InternalError ### In index.ts The main server file catches our errors and maps them: ```typescript import { mapToMcpError } from './adapters/mcp-sdk'; try { const result = await toolFunction(args); return { content: [{ type: 'text', text: JSON.stringify(result) }] }; } catch (error) { throw mapToMcpError(error, toolName); } ``` ## Testing When testing tools, mock the adapter: ```typescript jest.mock('../adapters/mcp-sdk', () => ({ ValidationError: jest.fn(), TimezoneError: jest.fn(), // ... other errors })); ``` This keeps tests focused on tool logic, not SDK behavior. ## Architecture ``` /adapters/mcp-sdk/ index.ts - Public API (what tools import) errors.ts - Our error class hierarchy mapper.ts - Maps our errors to MCP SDK types.d.ts - Fixes SDK type definitions README.md - This file ``` ## Future-Proofing When the MCP SDK changes (and it will), we only update this adapter. Our tools remain unchanged because they import from here, not the SDK.