Why Cline Doesn't Index Your Codebase (and Why That's a Good Thing)

Summary

Here's a common question we get from prospective Cline users: "How does Cline handle large codebases? Do you use RAG to index everything?"It's a reasonable question. Retrieval Augmented Generation (RAG) has become the go-to solution for giving AI systems access to large knowledge bases. But for Cline, we've taken a deliberately different path. We don't index your codebase, and this choice isn't an oversight's a fundamental design decision that delivers better code quality, stronger security, and more reliable results.Here's why.Why RAG Breaks Down for CodeRAG emerged as a clever solution to a real problem: early language models had limited context windows, so we needed ways to feed them relevant information from larger datasets. The approach seems straightforward – chunk your data, create embeddings, store them in a vector database, and retrieve relevant pieces when needed.But code isn't like other data. It's interconnected, constantly evolving, and often contains your most sensitive intellectual property. When you apply traditional RAG approaches to codebases, three critical problems emerge:1. Code Doesn't Think in ChunksRAG can be roughly divided into two parts: indexing the knowledge base (codebase in our case) and retrieval. But here's the problem: when you chunk code for embeddings, you're literally tearing apart its logic.Imagine trying to understand a symphony by listening to random 10-second clips. That's what RAG does to your codebase. A function call might be in chunk 47, its definition in chunk 892, and the critical context that explains why it exists? Scattered across a dozen other fragments.Even sophisticated approaches struggle with this. Chunking is relatively simple for natural language text — paragraphs (and sentences) provide obvious boundary points for creating semantically meaningful segments. However, naive chunking methods struggle with accurately delineating meaningful segments of code.2. Indexes Decay While Code EvolvesSoftware development mo...