Claude Memory Tool: Persistent Agent State in Python

Anthropic shipped a primitive that finally fixes the most painful thing about long-running agents: they forget. The memory tool, available right now on the Claude Developer Platform, lets your agent read and write files in a /memories directory that survives across requests, conversations, and even context-window resets.

This is not retrieval-augmented generation, it is not a vector database, and it is not the older Managed Agents memory store. It is a simple, file-based tool call that Claude initiates and your application executes. You own the bytes. You decide whether they live in a local folder, Postgres, S3, or an encrypted volume.