Structure-Aware Codebase Retrieval (Repo Map)

Retrieval specialized for code that exploits program structure instead of (or alongside) embeddings. The repo is parsed into ASTs and a symbol and dependency graph with tree-sitter; files and symbols are ranked by graph centrality (Aider's PageRank-weighted tag map), graph-traversal tools walk call, definition, and import edges (AutoCodeRover and code-graph agents), and spectrum-based fault localization can narrow the search from failing tests. This lets a coding agent assemble a minimal, relevant context from a repository far larger than its context window. Distinct from `graph-rag`, whose graph is built from document entities rather than from code semantics.