Anthropic Launches Enterprise Frontier Safeguards to Combine Zero-Data-Retention and Cross-Session Misuse Detection

Under EFS, activity data used for monitoring can be stored in cloud infrastructure under the customer's control, while detection remains with Anthropic. Customers keep custody, encryption keys, access policies and audit logging. Anthropic said EFS is not yet available; it will roll out in phases, with broad availability planned later this fall and access available on request. Until the architecture ships, eligible customers can run Claude Fable 5 and Fable 5.1 under a zero-data-retention commitment.

Anthropic said its reason for keeping monitoring data is detection quality, not training, and that it has never trained on enterprise data without explicit permission. The most sophisticated misuse observed by the company spans many tasks, sessions and accounts, including cases with stolen enterprise credentials. Running an automated classifier on each interaction and discarding the data immediately cannot catch that shape of attack, so correlation requires a time window. EFS moves the window into the customer's environment rather than removing it.

Anthropic developed EFS with more than 100 customers across financial services, healthcare, manufacturing, telecom, law, retail and the public sector, along with AWS, Google Cloud and Microsoft Azure. The company said design conversations covered a quarter of the Fortune 100 and every U.S. global systemically important bank. Three design decisions came out of the process: activity data can reside in the customer's own cloud bucket under their encryption keys and access policies; when automated monitoring detects a pattern worth attention, the signal goes directly to the customer; and automated systems analyze a rolling window of traffic for attempted offensive cyber or biological capability and signs of stolen or leaked credentials. No Anthropic human review is required.

EFS was announced alongside Claude Fable 5.1 and Mythos 5.1. Fable 5.1 cut cache reads by 75% to $0.25 per million tokens, resulting in roughly 25% lower cost on typical workloads and up to about 45% on highly agentic ones. Its cybersecurity safeguards also produce about 60% fewer interventions per Claude Code session than Fable 5's, partly because Fable 5.1 is allowed to identify software vulnerabilities without developing exploits for them. Anthropic charges nothing for EFS; the customer's cloud provider bills for storage and egress.