State and memory

An agentAgentA program that uses a language model to decide what to do (search, call a tool, answer, refuse), in a loop, with stopping rules.See in the glossary →Close can remember a preference and the latest questions, provided it first writes down what it keeps, for whom, and for how long. A memory with no owner or no limit leaks from one user to another, grows without end, or keeps what it never should have: a key, an address.

The concept

Think of a private bank’s client file. One file per client, never read by another adviser without the right to, and a retention policyRetention policyWhat a memory keeps, why, how to correct it, when it expires, and what it refuses to keep. Written before the first record.See in the glossary →Close written before the first file is opened.

1. A minimal state: one preference, and the last five exchanges.
2. The preference changes the question before the model call.
3. A written storage policy.
4. A memory indexed by (user, key).
5. Copies on the way in and on the way out.

How I worked

As since Session 4: the code and the storage policy are written by the assistant, tested against the real grader and explained line by line; I reran the check myself before handing in.

What the hand-in contains

• answer_with_state. If the preference is “short”, the question gets “(answer briefly)” before the model call. .get avoids an error when the preference doesn’t exist. Then del state.episodes[:-5] erases everything but the last five exchanges: the memory has a cap.
• The storage policy, in five lines: what is kept, why, how to correct it, when it expires, and what it refuses to keep: secrets, wallet keys, personal data.
• MemoryStore.
  • An empty or missing user ID is refused, on write as on read.
  • The key is the pair (owner, key): two users can each have their own locale.
  • A missing key returns None, without looking anywhere else.
  • deepcopy on the way in and out: nobody changes the memory by editing their own list.

What I keep

• You write the memory policy before storing anything, refusalsRefusalAn explicit "I can't answer": no citation, zero confidence, human review. A state, not a crash.See in the glossary →Close included.
• A memory is filed by owner, never in a shared bucket.
• Return a copy, not the object: otherwise the reader becomes a second writer.

The defense question

Does your agent mix up two clients’ memories?

No: every value is filed under the pair (user, key), an empty user is refused, and a missing key returns None without looking anywhere else. And the written policy refuses to keep secrets, wallet keys and personal data.

Result: 300/300, handed in through PR #559.