How I built Multi-User Memory Isolation with Hindsight Banks

Last week I realized our AI was sharing one user's excuses with a completely different person — fixing it with Hindsight banks took exactly three lines of code. What We Built AXIOM is a discipline accountability agent for engineering students. It tracks goals, scores discipline out of 1000, builds personalized daily plans, and remembers everything you tell it across sessions using Hindsight persistent memory. My specific contribution was solving the multi-user problem — making sure each user's memory is completely private and isolated from everyone else's. The Problem: One Brain, Many Users Our initial implementation used a single Hindsight memory bank for everyone: BANK_ID = " discipline-bot " This meant every user's memories went into the same pool. When User A logged in, recall() might return memories from User B's sessions. The agent was accidentally sharing one person's goals, failures, and excuses with a completely different person. For a discipline agent where the whole point is