Why I Built a Code Intelligence Platform in 6 Days (And What MCP Servers Actually Solve)
Everyone's talking about AI coding tools. But here's the problem nobody mentions: LLMs don't understand your codebase. They understand code in general. When your company has 63 repositories, a proprietary DSL, and calculation chains that span 15 files — "code in general" isn't enough.
At Taxwell, our tax calculation engine lives across two very different codebases: PowerBASIC (Drake) and MathMaster DSL (TaxAct). When we started using Claude Code for development work, we hit a wall immediately. The AI would confidently generate code using syntax that didn't exist. It would trace a calculation chain halfway and then fabricate the rest. It would suggest changes to functions without understanding that 47 other functions depended on them.
The answer wasn't better prompts. The answer was giving the AI a structured knowledge layer it could query. That's what Model Context Protocol (MCP) servers do — they give LLMs tools to look things up instead of guessing.
I built our code intelligence MCP server over a long weekend that turned into 6 days. The architecture is straightforward: an offline indexer parses all 63 repos and builds a SQLite database with FTS5 full-text search. Function definitions, call relationships, DSL field dependencies, cross-form references, include chains — all pre-computed and queryable. The MCP server exposes 37+ tools that Claude Code can call: search_code, get_call_chain, get_calculation_flow, get_form_dependencies, find_references.
The result? Questions that used to take hours of manual file-hopping now take seconds. "What breaks if I change this function?" has a real answer. "Trace the Earned Income Credit calculation end to end" returns the complete chain instead of a hallucinated approximation.
The lesson for other technical leaders
If your team is using AI coding tools and getting mediocre results, the problem probably isn't the AI. The problem is that the AI doesn't have access to the relationships and context that live in your engineers' heads. An MCP server — even a simple one backed by SQLite — can be the difference between an AI that wastes time and an AI that multiplies your team's output.
You don't need a vector database. You don't need embeddings. You need a well-indexed relational model of your codebase and a way for the AI to query it. Start there.