CodeSpine is a Python MCP server that indexes your Java project once and serves structural info to AI agents on demand. Instead of reading 30 files per query, it makes one MCP call and returns caller trees, impact paths, dead code reports, and execution flows. Features: hybrid BM25+fuzzy search, git change coupling, multi-module support, dirty overlay for in-progress edits. Zero hallucinations, 90% fewer tokens. MIT licensed.