Anthropic updates Python SDK with new Admin API features and Managed Agents support

Anthropic released version 1.10.0 of the anthropic-sdk-python on September 30, 2026, introducing several new features and bug fixes aimed at enterprise users of Managed Agents and the Admin API.

The update adds a refusal stop reason and stop_details to Managed Agents session idle events, improving transparency around why sessions terminate. It also introduces support for Claude Enterprise analytics, spend limits, and role-based access control (RBAC) groups within the Admin API, giving administrators finer-grained control over usage and permissions.

New per-user usage and cost reports have been added to the Admin API analytics, allowing organizations to track individual consumption and costs. The Admin API now also includes support for Plugins and Plugin Marketplaces, enabling centralized management of plugin installations and configurations.

For Managed Agents, the SDK adds repository error types to session errors and allows removal of an organization-wide plugin installation setting. The release also includes beta support for MCP Tunnels, with read-only transport objects added to the Tunnel interface and one-time relay tokens returned in the create response.

Bug fixes include making memory store description, metadata, and archived_at fields required, and type enforcement for admin plugin preference and marketplace fields as enums. Security improvements prevent configuration files that are group- or world-writable from being loaded.

Pagination behavior has been corrected to continue auto-paging past an empty page when next_page is set, and the session tool runner now stops after any idle event that ends the turn. Documentation and type definitions for MCP Tunnels have been updated, and tests now match mocked binary routes when requests include query parameters.

The release also includes CI and internal formatting changes, such as running tests in parallel on the oldest and newest supported Python versions and formatting request options with one argument per line.