Democratizing Internal Data — Building an MCP Server That Lets You Search 991 Tables in Natural Language

Ryan Tsuji, CTO at airCloset, built DB Graph MCP — a Model Context Protocol server that enables natural language search across 15 schemas, 991 tables, 11 SQL databases, and 6 MongoDB instances via Claude Code. The system solves the institutional knowledge problem where cross-schema relationships (often lacking foreign keys) exist only in a few engineers' heads, causing investigation bottlenecks. The architecture includes a daily batch job parsing ORM definitions from 28 repositories into a BigQuery graph, a review UI for human verification, and an MCP server for safe production querying.