The most common frustration with Claude Code is re-explaining the same context at the start of every session. "We use Drizzle, not Prisma." "Don't use any in TypeScript." "The auth is in /src/lib/auth.ts ." Claude has three mechanisms for remembering across sessions. They solve different problems and are appropriate in different situations. Using the wrong one means either re-explaining constantly or contaminating context you didn't want shared. The Three Mechanisms at a Glance...