Anthropic opens a private beta of Claude Managed Agents hosted entirely by the customer

Managed Agents is Anthropic's set of APIs for building and deploying autonomous agents. It supplies "the agent harness, sandboxes, credential handling, and session history". It launched as a service Anthropic hosts, and Anthropic later let customers host the sandbox. In the new version, "every part of the service runs in your own cloud or on-premise". The customer operates the Managed Agents server, its database and the workers where agents run their shell and file tools. Model requests go where the customer chooses: Anthropic directly, Amazon Bedrock, Google's Agent Platform, Microsoft Foundry, or the customer's own gateway. Session history is stored in the customer's database.

The post gives four design principles and says they apply in all three hosting arrangements. The harness that calls Claude is kept separate from the sandbox where the agent's code runs, and the agent loop, session history and vault secrets stay outside the sandbox. For MCP tools and supported API calls, a proxy outside the sandbox adds the credential to the request. Each environment can be limited to a list of allowed hosts. Every session leaves a record of each step, which exports over OpenTelemetry. Anthropic's stated reason: "you can't rely on a person checking every step, so the limits have to be built into the system itself."

Access is by request through an Anthropic account team. The post gives no pricing, no system requirements and no customer results. We did not open the documentation it links to.

Why it matters: For teams that wanted the whole agent service inside their own network, the post says, "Until now, that meant building the platform themselves." Those teams now have a vendor-built option to compare with their own harness, though only in private beta. The four principles also work as questions to put to a home-built setup: where the agent loop runs, where secrets live, what the sandbox can reach, and what record a run leaves.