Source Intelligence
Follow Discord

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

← All of v2.1.227 Home All releases ←olderv2.1.226 v2.1.228newer→
Claude Code v2.1.227

Tool-search beta header falls back when experimental betas are turned off

You'll notice
Useful2 Signal3
Tool Search

Turning off experimental betas now falls back to the older tool-search beta header everywhere.

What

Sessions that disable experimental betas now send the older tool-search-tool-2025-10-19 beta header instead of advanced-tool-use-2025-11-20. Previously the older header was used only on Vertex, Bedrock, Mantle and gateway providers.

Details
  • Triggered by the CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS environment variable or by HIPAA compliance mode.
  • Provider-based selection of the older header is unchanged.
Evidence

advanced-tool-use-2025-11-20

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.227 →