Self-hosted Claude Managed Agents keeps agent credentials in your environment

Anthropic's self-hosted Claude Managed Agents offering highlights a critical shift in responsibility: when agent harnesses, sandboxes, and credentials move into a customer's own environment, that customer now owns the security of those assets. If credentials stored in internal secrets managers are misconfigured, over-permissioned, or inadequately audited, unattended agents can become a high-value attack vector with little human oversight. The architecture's emphasis on separating harnesses from sandboxes and using host allowlists reflects sound design principles, but those controls only work if operators implement and maintain them correctly. This matters because agentic AI systems often act autonomously over extended periods, meaning a compromised credential can cause significant damage before anyone notices.