Claude Code resets context every session. MEMORY.md gives it persistent memory of your project's evolving state in a 200-line index file. Setup takes 5 minutes. One prompt at the end of each session keeps it current. # Session 1: "This project uses Clerk for auth, not NextAuth." # Session 2: "As I mentioned, we use Clerk..." # Session 3: "We migrated to Clerk in March. Stop suggesting NextAuth." # Session 4: "READ THE CLAUDE.MD. We use Clerk." # Session 5: "..." # Session 6: *opens CLAUDE.md, adds it in bold, all caps* Enter fullscreen mode Exit fullscreen mode Sound familiar? Developers spend 10-15 minutes per session rebuilding context that was clear yesterday ( CleanAim, 2026 ). Over a month of daily sessions, that's 5-10 hours of repeating yourself. The fix is one file. MEMORY.md is a lightweight index that Claude Code reads at session start. Not a conversation log. Not a code dump. A table of contents for your project's current state.…