Agent Memory Gateway is a policy gateway that sits in front of the memory AI agents share, and every write and read has to pass through it. Before a memory is stored, the gateway scans it for credentials. If it finds one, it quarantines the whole write, so the secret never reaches the knowledge base (Senso). Each memory keeps the access restrictions of the sources it came from, and the server checks the reader's current permissions on every read. Agents hold only short-lived, run-scoped gateway tokens and never the backend keys, so a hand-written script calling the API gets the same decision as the agent's own client. In a live demo on AWS, with AkashML agents, Senso memory and ClickHouse audit logs, the same note causes a real cross-customer data breach without the gateway. With the gateway, that note is blocked, while the agent still publishes a useful, source-linked report.