MCP WooCommerce Server

import { Tool } from '@modelcontextprotocol/sdk/types.js'; import { Logger } from '../utils/logger.js'; /** * N8N Compatibility Layer for MCP Tools * Ensures all tool schemas are fully compatible with N8N's expected format */ export class N8nCompatibility { private logger: Logger; constructor(logger: Logger) { this.logger = logger; } /** * Convert MCP tool schema to N8N-compatible format */ convertToolForN8n(tool: Tool): any { const n8nTool = { name: tool.name, description: tool.description, schema: { type: 'object', properties: tool.inputSchema?.properties || {}, required: tool.inputSchema?.required || [], additionalProperties: false } }; // Ensure all properties have proper JSON Schema validation if (n8nTool.schema.properties) { Object.keys(n8nTool.schema.properties).forEach(key => { const property: any = n8nTool.schema.properties[key]; // Add default values if missing if (!property.type) { property.type = 'string'; } // Ensure proper format for N8N if (property.type === 'string' && !property.description) { property.description = `Input parameter: ${key}`; } // Handle enum values properly if (property.enum && Array.isArray(property.enum)) { property.enum = property.enum.map((val: any) => String(val)); } }); } this.logger.debug('Converted tool for N8N compatibility', { toolName: tool.name, originalSchema: tool.inputSchema, n8nSchema: n8nTool.schema }); return n8nTool; } /** * Validate tool input against N8N requirements */ validateToolInput(toolName: string, input: any): { valid: boolean; errors?: string[] } { const errors: string[] = []; // Basic validation if (typeof input !== 'object' || input === null) { errors.push('Input must be a valid object'); } // Check for common N8N issues if (input && typeof input === 'object') { Object.keys(input).forEach(key => { const value = input[key]; // N8N doesn't handle undefined values well if (value === undefined) { errors.push(`Property '${key}' is undefined - should be null or omitted`); } // Check for invalid characters in string values if (typeof value === 'string' && value.includes('\u0000')) { errors.push(`Property '${key}' contains null character`); } }); } return { valid: errors.length === 0, errors: errors.length > 0 ? errors : undefined }; } /** * Sanitize tool input for N8N processing */ sanitizeToolInput(input: any): any { if (!input || typeof input !== 'object') { return {}; } const sanitized: any = {}; Object.keys(input).forEach(key => { const value = input[key]; // Remove undefined values if (value === undefined) { return; } // Sanitize strings if (typeof value === 'string') { sanitized[key] = value.replace(/\u0000/g, '').trim(); } // Handle arrays else if (Array.isArray(value)) { sanitized[key] = value.filter(item => item !== undefined); } // Handle objects else if (value && typeof value === 'object') { sanitized[key] = this.sanitizeToolInput(value); } // Handle primitives else { sanitized[key] = value; } }); return sanitized; } /** * Format tool response for N8N compatibility */ formatToolResponse(response: any): any { // Ensure response has proper structure for N8N if (!response || typeof response !== 'object') { return { success: false, error: 'Invalid response format', data: null }; } // If it's already properly formatted, return as-is if (response.content && Array.isArray(response.content)) { return response; } // Convert to proper MCP response format return { content: [{ type: 'text', text: typeof response === 'string' ? response : JSON.stringify(response, null, 2) }], isError: false }; } /** * Create N8N-compatible error response */ createErrorResponse(error: string | Error): any { const errorMessage = error instanceof Error ? error.message : error; return { content: [{ type: 'text', text: JSON.stringify({ success: false, error: errorMessage, timestamp: new Date().toISOString() }, null, 2) }], isError: true }; } /** * Get all available tools in N8N-compatible format */ getN8nCompatibleTools(tools: Tool[]): any[] { return tools.map(tool => this.convertToolForN8n(tool)); } /** * Process tool execution with N8N compatibility layer */ async processToolExecution( toolName: string, input: any, originalHandler: (name: string, args: any) => Promise<any> ): Promise<any> { try { // Validate input const validation = this.validateToolInput(toolName, input); if (!validation.valid) { this.logger.error('N8N tool input validation failed', { toolName, input, errors: validation.errors }); return this.createErrorResponse(`Input validation failed: ${validation.errors?.join(', ')}`); } // Sanitize input const sanitizedInput = this.sanitizeToolInput(input); // Execute original handler const result = await originalHandler(toolName, sanitizedInput); // Format response for N8N return this.formatToolResponse(result); } catch (error) { this.logger.error('N8N tool execution error', { toolName, input, error: error instanceof Error ? error.message : error }); return this.createErrorResponse(error instanceof Error ? error : 'Unknown execution error'); } } }