MCP_Server_n8n_

CRITICAL: The `postgresql.py` file contains a hardcoded PostgreSQL connection string (`psqlurl`) including database credentials (owner username and password). This is a severe security vulnerability. While the README suggests using environment variables, the code does not implement this. Additionally, the project encourages public exposure via ngrok, which, while noted as optional, combined with hardcoded credentials and the direct database query capabilities, poses a significant risk if not handled with extreme care. The `mcp.tool()` functions use parameterized queries, mitigating direct SQL injection for the defined tools, but the general `query_db` function could be misused if new tools are added without proper parameterization.