Why Flat Files Break as AI Agent Memory (And What We Built Instead)

Your AI coding agent has amnesia. Every Claude Code session, every Cursor chat, every Windsurf interaction starts from zero. The architectural decision you explained on Monday? Gone. The debugging lesson from Friday? Never happened. The style preferences you've stated twelve times? Say them again. The common fix is a flat file. Claude Code has CLAUDE.md . Cursor has .cursorrules . They work — for a while. Then they don't. Where flat files break I kept hitting the same five failures as my CLAUDE.md grew past 200 lines: 1. Search is impossible. You're grepping for context that may or may not be there. The phrase you used three weeks ago doesn't match how you'd describe it today. 2. Nothing is auto-captured. Every lesson has to be manually written. You debug a Docker volume mount issue for 30 minutes, and unless you type "remember this," it's gone. 3. It grows forever. No deduplication. No decay. No contradiction detection. "We use REST" from January sits next to "We migrated to WebSocket