Missing `code_execution-2025-08-25` beta header prevents use of non-legacy Code Execution tool

[PederHP]

Title

Missing code_execution-2025-08-25 beta header prevents use of new Code Execution tool

Description

Problem

The AnthropicBeta enum currently only includes the legacy code_execution-2025-05-22 beta header value. The newer code_execution-2025-08-25 header is missing, which prevents users from enabling the updated Code Execution server-side tool.

Impact

• Microsoft.Extensions.AI users: The HostedCodeInterpreterTool in the MEAI extensions maps to the new code execution tool, but there's no way to pass the required beta header through the SDK.
• Direct SDK users: Anyone wanting to use the latest code execution tool capabilities cannot do so, as the API rejects requests without the correct beta header.

Attempting to use the new code execution tool results in an API error since the legacy header only enables the legacy tool variant.

Expected Behavior

The SDK should expose CodeExecution2025_08_25 (or equivalent) in the AnthropicBeta enum so users can opt into the updated code execution functionality.

Reference

• [Code Execution Tool Documentation](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool)