MCPQL

#!/usr/bin/env node import { Server } from "@modelcontextprotocol/sdk/server/index.js"; import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"; import { CallToolRequestSchema, ListToolsRequestSchema } from "@modelcontextprotocol/sdk/types.js"; import { connectDB } from './db.js'; import { MCP_MSQL_TOOLS } from './tools.js'; import * as toolHandlers from './mcp-server.js'; import fs from 'fs'; import path from 'path'; import { fileURLToPath } from 'url'; // Get __dirname equivalent in ES modules const __filename = fileURLToPath(import.meta.url); const __dirname = path.dirname(__filename); // Setup file logging function logToFile(message, ...args) { const logFile = path.join(__dirname, '..', 'mcp_debug.log'); const timestamp = new Date().toISOString(); const logMessage = `[${timestamp}] ${message} ${args.map(arg => typeof arg === 'object' ? JSON.stringify(arg) : arg).join(' ')}\n`; try { fs.appendFileSync(logFile, logMessage); console.error(message, ...args); // Also log to console } catch (err) { console.error('Error writing to log file:', err); } } // Function to safely prepare data for MCP response (minimal processing) function prepareDataForResponse(data) { try { let serialized = JSON.stringify(data, (key, value) => { // Only handle truly problematic values, preserve SQL content if (value === undefined) return null; if (typeof value === 'function') return '[Function]'; if (value instanceof Date) return value.toISOString(); return value; // Keep everything else as-is, including long strings and special chars }, 2); logToFile(`[DEBUG] Response serialized successfully, length: ${serialized.length}`); return serialized; } catch (error) { logToFile(`[DEBUG] Data preparation error: ${error.message}`); return `[Data Preparation Error: ${error.message}]`; } } // Create the server with name and version // @ts-ignore - Bypass TypeScript errors from the SDK's types const server = new Server({ name: "msql-proxy-server", version: "1.0.0" }, { capabilities: { tools: {} } }); // Register the ListTools handler // @ts-ignore - Bypass TypeScript errors from the SDK's types server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: MCP_MSQL_TOOLS })); // Register the CallTool handler // @ts-ignore - Bypass TypeScript errors from the SDK's types server.setRequestHandler(CallToolRequestSchema, async (request) => { const toolName = request.params.name; const input = request.params.arguments; const handler = toolHandlers[toolName]; if (!handler) { return { content: [ { type: "text", text: `Error: Tool '${toolName}' not found.` } ], isError: true }; } try { await connectDB(); let result; switch (toolName) { case 'mcp_get_sp_all_info_simple': result = await toolHandlers.mcp_get_sp_all_info_simple(input); break; case 'mcp_preview_data_enhanced': result = await toolHandlers.mcp_preview_data_enhanced(input); break; case 'mcp_get_sample_values': result = await toolHandlers.mcp_get_sample_values(input); break; case 'mcp_get_column_stats_enhanced': result = await toolHandlers.mcp_get_column_stats_enhanced(input); break; case 'mcp_quick_data_analysis': result = await toolHandlers.mcp_quick_data_analysis(input); break; case 'mcp_search_objects_by_name': result = await toolHandlers.mcp_search_objects_by_name(input); break; case 'mcp_search_in_definitions': result = await toolHandlers.mcp_search_in_definitions(input); break; case 'mcp_search_objects_by_type': result = await toolHandlers.mcp_search_objects_by_type(input); break; case 'mcp_get_object_dependencies': result = await toolHandlers.mcp_get_object_dependencies(input); break; case 'mcp_search_comprehensive': result = await toolHandlers.mcp_search_comprehensive(input); break; default: result = await handler(input); } logToFile(`[DEBUG] Tool: ${toolName}, Success: ${result.success}`); // Check if the handler result indicates an error if (!result.success) { logToFile(`[DEBUG] Handler error: ${result.error}`); const errorResponse = { content: [ { type: "text", text: `Error: ${result.error}` } ], isError: true }; logToFile(`[DEBUG] About to return error response for tool: ${toolName}`); return errorResponse; } // Safely prepare the data for response const serializedData = prepareDataForResponse(result.data); logToFile(`[DEBUG] Returning data length: ${serializedData.length}`); // Return successful result data only const response = { content: [ { type: "text", text: serializedData } ] }; logToFile(`[DEBUG] About to return successful response for tool: ${toolName}`); // Log after response is sent setImmediate(() => { logToFile(`[DEBUG] Response sent successfully for tool: ${toolName}`); }); return response; } catch (error) { logToFile(`[DEBUG] Catch block error: ${error.message}`); logToFile(`[DEBUG] Error stack: ${error.stack}`); const catchErrorResponse = { content: [ { type: "text", text: `Error executing tool '${toolName}': ${error.message}` } ], isError: true }; logToFile(`[DEBUG] About to return catch error response for tool: ${toolName}`); return catchErrorResponse; } // Don't close the connection after each call to allow multiple tool calls in the same session // The connection will be managed by the MCP's own lifecycle }); // Start the server using stdio transport // This is exactly how the working example does it async function runServer() { const transport = new StdioServerTransport(); await server.connect(transport); logToFile("=== SQL Server MCP Proxy STARTED ==="); console.error("SQL Server MCP Proxy running on stdio"); } runServer().catch((error) => { console.error("Fatal error running server:", error); process.exit(1); });