Building Your Own "Google Maps for Codebases": A Guide to Codebase Q&A with LLMs

From Overwhelm to Insight: Navigating the Modern Code Jungle You clone a promising repository, ready to contribute or understand its magic. You’re greeted by dozens of directories, hundreds of files, and a README that ends at "Getting Started." Sound familiar? Navigating a complex, unfamiliar codebase remains one of software development's most universal and time-consuming challenges. The recent popularity of tools that act as a "Google Maps for codebases"—where you paste a GitHub URL and ask questions—highlights our collective desire to cut through this complexity. But what if you could build the core of this capability yourself? In this guide, we'll move from being a user of these AI-powered navigators to an architect. We'll build a foundational system that ingests a codebase, understands its structure and content, and answers your questions in plain English. We'll use open-source tools, focusing on the practical pipeline rather than black-box APIs. The Architectural Blueprint: RAG fo