Oracle Database Model Context Protocol Server

import { spawn } from 'child_process';
import * as path from 'path';

// Define the environment variables for the MCP server
// For production, use a secure method to manage credentials.
const env = {
  ORACLE_CONNECTION_STRING: process.env.ORACLE_CONNECTION_STRING ?? 'localhost:1521/XEPDB1',
  ORACLE_USER: process.env.ORACLE_USER ?? 'your_readonly_user',
  ORACLE_PASSWORD: process.env.ORACLE_PASSWORD ?? 'your_password',
  ORACLE_POOL_MIN: process.env.ORACLE_POOL_MIN ?? '2',
  ORACLE_POOL_MAX: process.env.ORACLE_POOL_MAX ?? '10',
  QUERY_TIMEOUT_MS: process.env.QUERY_TIMEOUT_MS ?? '30000',
  MAX_ROWS_PER_QUERY: process.env.MAX_ROWS_PER_QUERY ?? '1000',
  // Inherit current process environment to ensure basic PATH, etc.
  ...process.env,
};

// The executable command as installed via npm -g or in node_modules/.bin
const command = 'mcp-database-server';

console.log(`Attempting to start MCP Oracle Database Server with command: ${command}`);
console.log('Ensure ORACLE_CONNECTION_STRING, ORACLE_USER, ORACLE_PASSWORD are set via environment variables.');

// Spawn the server process, similar to how an MCP client would
const serverProcess = spawn(command, [], {
  env,
  stdio: ['pipe', 'pipe', 'pipe'], // Capture stdin, stdout, stderr
});

serverProcess.stdout.on('data', (data) => {
  console.log(`[Server stdout]: ${data.toString().trim()}`);
});

serverProcess.stderr.on('data', (data) => {
  console.error(`[Server stderr]: ${data.toString().trim()}`);
});

serverProcess.on('close', (code) => {
  console.log(`MCP Oracle Database Server process exited with code ${code}`);
});

serverProcess.on('error', (err) => {
  console.error(`Failed to start MCP Oracle Database Server process: ${err.message}`);
});

// In a real scenario, an MCP client would then write JSON-RPC messages to serverProcess.stdin.
// For example, to send an 'initialize' message after a delay:
/*
setTimeout(() => {
  const initializeMessage = {
    jsonrpc: '2.0',
    id: 1,
    method: 'initialize',
    params: { capabilities: {} }
  };
  console.log('Sending simulated MCP initialize message...');
  serverProcess.stdin.write(JSON.stringify(initializeMessage) + '\n');
}, 5000);
*/

// Keep the Node.js process alive for a bit to see output (optional)
setTimeout(() => {
  if (!serverProcess.killed) {
    console.log('Simulated parent process exit after 60 seconds.');
    serverProcess.kill(); // Terminate the child process
  }
}, 60000);